Evaluation of Supermarket Food Waste as partial replacement of commercial feed un Mozambique Tilapia, Oreochromis Mossambicus Culture
- Vundisa, N, Makhawana, J, Xiki, X, Okuthe, G E
- Authors: Vundisa, N , Makhawana, J , Xiki, X , Okuthe, G E
- Date: 2021
- Language: English
- Identifier: http://hdl.handle.net/11260/6409 , vital:45478
- Full Text:
- Authors: Vundisa, N , Makhawana, J , Xiki, X , Okuthe, G E
- Date: 2021
- Language: English
- Identifier: http://hdl.handle.net/11260/6409 , vital:45478
- Full Text:
Morphology, histology and histochemistry of the digestive tract of the Banded tilapia, Tilapia sparrmanii (Perciformes: Cichlidae)
- Grace E. Okuthe, Bongile Bhomela
- Authors: Grace E. Okuthe , Bongile Bhomela
- Date: December 23, 2020
- Subjects: Fish, gastrointestinal tract, histo-architecture
- Language: English
- Type: Journal Article
- Identifier: http://hdl.handle.net/11260/2425 , vital:41881
- Description: ABSTRACT. This study described anatomical, histological and histochemical features of the mucosal layer of the digestive tract of Tilapia sparrmanii Smith, 1840, an omnivorous freshwater fish endemic to Southern Africa. This species exhibited a short thick oesophagus with long deep longitudinal folds (466.68 ± 16.91 µm), and a thick (173.50 ± 10.92 µm) muscular layer that allow the passage of large food items. The mucosa was lined with stratified secretory epithelium rich in goblet cells that secreted neutral and acid mucins. The stomach was a sac-like structure with simple tubular glands surrounded by connective tissue. The mucosa was lined with simple columnar epithelium and the lamina propria exhibited a well-developed layer of gastric glands that occupied the entire length of the cardio-fundic region. The stomach mucosa consisted of epithelial cells with intense neutral mucin secretion which protects against gastric juice. Neck cells of gastric glands synthesized neutral and acid mucins. The intestine was highly coiled and presented a complex pattern of transversal folds internally (villi). Villi length decreased progressively from the anterior to the posterior intestine (p < 0.0001). Tunica muscularis of the mid-intestine had the thinnest thickness among all parts of the intestine (p < 0.0001). Goblet cells whose numbers increased towards the rectum secreted both acid and neutral mucins. The results indicate structural similarities of T. sparrmanii GIT with other tilapia species and will be useful for understanding the physiology of the digestive systems as well as functional components of the GIT.
- Full Text:
- Authors: Grace E. Okuthe , Bongile Bhomela
- Date: December 23, 2020
- Subjects: Fish, gastrointestinal tract, histo-architecture
- Language: English
- Type: Journal Article
- Identifier: http://hdl.handle.net/11260/2425 , vital:41881
- Description: ABSTRACT. This study described anatomical, histological and histochemical features of the mucosal layer of the digestive tract of Tilapia sparrmanii Smith, 1840, an omnivorous freshwater fish endemic to Southern Africa. This species exhibited a short thick oesophagus with long deep longitudinal folds (466.68 ± 16.91 µm), and a thick (173.50 ± 10.92 µm) muscular layer that allow the passage of large food items. The mucosa was lined with stratified secretory epithelium rich in goblet cells that secreted neutral and acid mucins. The stomach was a sac-like structure with simple tubular glands surrounded by connective tissue. The mucosa was lined with simple columnar epithelium and the lamina propria exhibited a well-developed layer of gastric glands that occupied the entire length of the cardio-fundic region. The stomach mucosa consisted of epithelial cells with intense neutral mucin secretion which protects against gastric juice. Neck cells of gastric glands synthesized neutral and acid mucins. The intestine was highly coiled and presented a complex pattern of transversal folds internally (villi). Villi length decreased progressively from the anterior to the posterior intestine (p < 0.0001). Tunica muscularis of the mid-intestine had the thinnest thickness among all parts of the intestine (p < 0.0001). Goblet cells whose numbers increased towards the rectum secreted both acid and neutral mucins. The results indicate structural similarities of T. sparrmanii GIT with other tilapia species and will be useful for understanding the physiology of the digestive systems as well as functional components of the GIT.
- Full Text:
Morphology, histology and histochemistry of the digestive tract of the Banded tilapia, Tilapia sparrmanii (Perciformes: Cichlidae)
- Grace E. Okuthe1, Bongile Bhomela1
- Authors: Grace E. Okuthe1 , Bongile Bhomela1
- Date: 2020
- Language: English
- Type: Journal article
- Identifier: http://hdl.handle.net/11260/4296 , vital:44088
- Full Text:
- Authors: Grace E. Okuthe1 , Bongile Bhomela1
- Date: 2020
- Language: English
- Type: Journal article
- Identifier: http://hdl.handle.net/11260/4296 , vital:44088
- Full Text:
Molecular Detection of Antibiotic-Resistant Genes in Pseudomonas aeruginosa from Nonclinical Environment: Public Health Implications in Mthatha, Eastern Cape Province, South Africa
- Mojisola Clara Hosu, Sandeep Vasaikar, Grace Emily Okuthe, Teke Apalata
- Authors: Mojisola Clara Hosu , Sandeep Vasaikar , Grace Emily Okuthe , Teke Apalata
- Date: 5 January 2021
- Subjects: Microbiology
- Language: English
- Type: Journal Article
- Identifier: http://hdl.handle.net/11260/2417 , vital:41877
- Description: Evaluation of resistant profiles and detection of antimicrobial-resistant genes of bacterial pathogens in the nonclinical milieu is imperative to assess the probable risk of dissemination of resistant genes in the environment. .is paper sought to identify antibiotic-resistant genes in Pseudomonas aeruginosa from nonclinical sources in Mthatha, Eastern Cape, and evaluate its public health implications. Samples collected from abattoir wastewater and aquatic environment were processed by membrane filtration and cultured on CHROMagarTM Pseudomonas medium. Species identification was performed by autoSCAN-4 (Dade Behring Inc., IL). Molecular characterization of the isolates was confirmed using real-time polymerase chain reaction (rPCR) and selected isolates were further screened for the possibility of harboring antimicrobial resistance genes. Fifty-one Pseudomonas species were recovered from abattoir wastewater and surface water samples, out of which thirty-six strains were Pseudomonas aeruginosa (70.6%). .e P. aeruginosa isolates demonstrated resistance to aztreonam (86.1%), ceftazidime (63.9%), piperacillin (58.3%), cefepime (55.6%), imipenem (50%), piperacillin/tazobactam (47.2%), meropenem (41.7%), and levofloxacin (30.6%). Twenty out of thirty-six P. aeruginosa displayed multidrug resistance profiles and were classified as multidrug-resistant (MDR) (55.6%). Most of the bacterial isolates exhibited a high Multiple Antibiotic Resistance (MAR) Index ranging from 0.08 to 0.69 with a mean MAR index of 0.38. In the rPCR analysis of fifteen P. aeruginosa isolates, 14 isolates (93.3%) were detected harboring blaSHV, six isolates (40%) harbored blaTEM, and three isolates (20%) harbored blaCTX-M, being the least occurring ESBL. Results of the current study revealed that P. aeruginosa isolates recovered from nonclinical milieu are resistant to frontline clinically relevant antipseudomonal drugs. .is is concerning as it poses a risk to the environment and constitutes a public health threat. Given the public health relevance, the paper recommends monitoring of multidrug-resistant pathogens in effluent environments.
- Full Text:
- Authors: Mojisola Clara Hosu , Sandeep Vasaikar , Grace Emily Okuthe , Teke Apalata
- Date: 5 January 2021
- Subjects: Microbiology
- Language: English
- Type: Journal Article
- Identifier: http://hdl.handle.net/11260/2417 , vital:41877
- Description: Evaluation of resistant profiles and detection of antimicrobial-resistant genes of bacterial pathogens in the nonclinical milieu is imperative to assess the probable risk of dissemination of resistant genes in the environment. .is paper sought to identify antibiotic-resistant genes in Pseudomonas aeruginosa from nonclinical sources in Mthatha, Eastern Cape, and evaluate its public health implications. Samples collected from abattoir wastewater and aquatic environment were processed by membrane filtration and cultured on CHROMagarTM Pseudomonas medium. Species identification was performed by autoSCAN-4 (Dade Behring Inc., IL). Molecular characterization of the isolates was confirmed using real-time polymerase chain reaction (rPCR) and selected isolates were further screened for the possibility of harboring antimicrobial resistance genes. Fifty-one Pseudomonas species were recovered from abattoir wastewater and surface water samples, out of which thirty-six strains were Pseudomonas aeruginosa (70.6%). .e P. aeruginosa isolates demonstrated resistance to aztreonam (86.1%), ceftazidime (63.9%), piperacillin (58.3%), cefepime (55.6%), imipenem (50%), piperacillin/tazobactam (47.2%), meropenem (41.7%), and levofloxacin (30.6%). Twenty out of thirty-six P. aeruginosa displayed multidrug resistance profiles and were classified as multidrug-resistant (MDR) (55.6%). Most of the bacterial isolates exhibited a high Multiple Antibiotic Resistance (MAR) Index ranging from 0.08 to 0.69 with a mean MAR index of 0.38. In the rPCR analysis of fifteen P. aeruginosa isolates, 14 isolates (93.3%) were detected harboring blaSHV, six isolates (40%) harbored blaTEM, and three isolates (20%) harbored blaCTX-M, being the least occurring ESBL. Results of the current study revealed that P. aeruginosa isolates recovered from nonclinical milieu are resistant to frontline clinically relevant antipseudomonal drugs. .is is concerning as it poses a risk to the environment and constitutes a public health threat. Given the public health relevance, the paper recommends monitoring of multidrug-resistant pathogens in effluent environments.
- Full Text:
In vitro antimicrobial photodynamic inactivation of multidrugresistant Acinetobacter baumannii biofilm using Protoporphyrin IX and Methylene blue
- Anane, Yaw Adjei, Apalata, Teke, Vasaikar, Sandeep, Okuthe, Grace Emily, Songca, Sandile Phinda
- Authors: Anane, Yaw Adjei , Apalata, Teke , Vasaikar, Sandeep , Okuthe, Grace Emily , Songca, Sandile Phinda
- Date: 2020
- Language: English
- Identifier: http://hdl.handle.net/11260/2273 , vital:41315
- Full Text:
- Authors: Anane, Yaw Adjei , Apalata, Teke , Vasaikar, Sandeep , Okuthe, Grace Emily , Songca, Sandile Phinda
- Date: 2020
- Language: English
- Identifier: http://hdl.handle.net/11260/2273 , vital:41315
- Full Text:
Molecular Detection of Carbapenemase-Encoding Genes in Multidrug-Resistant Acinetobacter baumannii Clinical Isolates in South Africa
- Anane, Yaw Adjei, Apalata, Teke, Vasaikar, Sandeep, Okuthe, Grace Emily, Songca, Sandile
- Authors: Anane, Yaw Adjei , Apalata, Teke , Vasaikar, Sandeep , Okuthe, Grace Emily , Songca, Sandile
- Date: 2020
- Language: English
- Type: Journal Article
- Identifier: http://hdl.handle.net/11260/2263 , vital:41314
- Description: https://www.hindawi.com/journals/ijmicro/2020/7380740/
- Full Text:
- Authors: Anane, Yaw Adjei , Apalata, Teke , Vasaikar, Sandeep , Okuthe, Grace Emily , Songca, Sandile
- Date: 2020
- Language: English
- Type: Journal Article
- Identifier: http://hdl.handle.net/11260/2263 , vital:41314
- Description: https://www.hindawi.com/journals/ijmicro/2020/7380740/
- Full Text:
Molecular Detection of Carbapenemase-Encoding Genes in Multidrug-Resistant Acinetobacter baumannii Clinical Isolates in South Africa
- Anane, Yaw Adjei, Okuthe, Grace Emily, Apalata, Teke, Vasaikar, Sandeep, Songca, Sandile
- Authors: Anane, Yaw Adjei , Okuthe, Grace Emily , Apalata, Teke , Vasaikar, Sandeep , Songca, Sandile
- Date: 2020
- Language: English
- Type: Journal Article
- Identifier: http://hdl.handle.net/11260/4351 , vital:44108
- Full Text:
- Authors: Anane, Yaw Adjei , Okuthe, Grace Emily , Apalata, Teke , Vasaikar, Sandeep , Songca, Sandile
- Date: 2020
- Language: English
- Type: Journal Article
- Identifier: http://hdl.handle.net/11260/4351 , vital:44108
- Full Text:
JOURNAL ARTICLE B.pdf
- Authors: Grace Emily Okuthe
- Subjects: sex inversion, danio rerio, gonad, mitotic, development
- Language: English
- Type: Journal Article
- Identifier: http://hdl.handle.net/11260/2333 , vital:41323
- Description: published papers by Prof Grace Emily Okuthe
- Full Text:
- Authors: Grace Emily Okuthe
- Subjects: sex inversion, danio rerio, gonad, mitotic, development
- Language: English
- Type: Journal Article
- Identifier: http://hdl.handle.net/11260/2333 , vital:41323
- Description: published papers by Prof Grace Emily Okuthe
- Full Text:
JOURNAL ARTICLE A.pdf
- Authors: Grace Emily Okuthe
- Subjects: sex inversion, danio rerio, gonad, mitotic, development
- Language: English
- Type: Journal Article
- Identifier: http://hdl.handle.net/11260/2325 , vital:41324
- Description: published papers by Prof Grace Emily Okuthe
- Full Text:
- Authors: Grace Emily Okuthe
- Subjects: sex inversion, danio rerio, gonad, mitotic, development
- Language: English
- Type: Journal Article
- Identifier: http://hdl.handle.net/11260/2325 , vital:41324
- Description: published papers by Prof Grace Emily Okuthe
- Full Text:
JOURNAL ARTICLE B.pdf
- Authors: Grace Emily Okuthe
- Subjects: danio rerio, gonad, mitotic/ meiotic transition, development, sex inversion
- Language: English
- Identifier: http://hdl.handle.net/11260/2305 , vital:41322
- Full Text:
- Authors: Grace Emily Okuthe
- Subjects: danio rerio, gonad, mitotic/ meiotic transition, development, sex inversion
- Language: English
- Identifier: http://hdl.handle.net/11260/2305 , vital:41322
- Full Text:
JOURNAL ARTICLE A.pdf
- Authors: Grace Emily Okuthe
- Subjects: danio rerio, gonad, mitotic/ meiotic transition, development, sex inversion
- Language: English
- Identifier: http://hdl.handle.net/11260/2317 , vital:41321
- Full Text:
- Authors: Grace Emily Okuthe
- Subjects: danio rerio, gonad, mitotic/ meiotic transition, development, sex inversion
- Language: English
- Identifier: http://hdl.handle.net/11260/2317 , vital:41321
- Full Text:
Biogenic synthesis of Silver nanoparticles (AgNPs) and its effects on Zebrafish (Danio rerio)
- Authors: Siguba, Busiswa
- Date: 2019
- Subjects: Biogenic synthesis -- Zebrafish , Nanoparticles – Silver , Zebrafish
- Language: English
- Type: Thesis , Masters , M Sc
- Identifier: http://hdl.handle.net/11260/1339 , vital:32260
- Description: The increase in use and production of engineered nanoparticles in recent years points towards their inevitable release into freshwater ecosystems. Subsequently, exposure to organisms in freshwater ecosystems is to be expected. The aim of this dissertation was to synthesize silver nanoparticles (AgNPs) using silver nitrate, gelatine and maltose as precursor, capping and reducing agent respectively. Cytotoxic effects of the as-synthesized AgNPs was evaluated at concentrations of 0.031 μg/L, 0.250 μg/L and 5.000 μg/L on selected target organs in zebrafish (Danio rerio ) after 96 hr of exposure, under a 24 hr static renewal system. Formation of AgNPs was investigated by UV-Vis spectrophotometry, which displayed absorption maxima peak characteristic of plasmon resonance band for silver at 419 nm. From transmission electron microscopy, AgNPs was found to be small, well dispersed and spherical in shape with a narrow size distribution, and an average particle size of3.76 ± 1.00 nm. Histopathological alterations following exposure to AgNPs was noticed in the gills, epidermis, muscle tissue and kidney. Secondary lamellae hypertrophy, oedema and epithelial lifting was observed in all experimental groups. Curling and clubbed tips of secondary lamellae were observed at the lowest concentration (0.031 μg/L). Hyperplasia and lamellae fusion was most common at the median concentration (0.250 μg/L) of AgNP exposure. Hypertrophy of endothelial cells along with blood vessel congestion was also observed. Reduced secondary lamellar length, lamellar erosion and thinning were observed at the highest concentration (5.000 μg/L).AgNP exposure also altered the shape of alarm cells. In addition, hyperplasia and hypertrophy of goblet cells were observed at the highest concentration (5.000 μg/L) at 96 hr. At 5.000 μg/L of AgNP, PAS reaction was intense (deep purple), while the number and size of these cells decreased. Staining with AB pH 2.5 demonstrated an intense deep purple staining at the lowest and at the median concentration (24 hr). Moderate staining was seen at the higher concentrations. Muscle bundles with severe oedema, their thickening and separation were more pronounced in all treated groups. Histopathological tubular deformation and mononuclear cell infiltration were observed in kidney tissues. In addition; an increase in melano‐macrophage aggregation intensity was identified on the 48 hr in the treated groups. An increase in tubular epithelial cell regeneration/ proliferation, resulting in production of new epithelial cells which was indicative of recovering of kidney tissues from AgNP induced injury at 96 hr of exposure. Results presented here shows that fish respond to the presence of AgNPs.
- Full Text:
- Date Issued: 2019
- Authors: Siguba, Busiswa
- Date: 2019
- Subjects: Biogenic synthesis -- Zebrafish , Nanoparticles – Silver , Zebrafish
- Language: English
- Type: Thesis , Masters , M Sc
- Identifier: http://hdl.handle.net/11260/1339 , vital:32260
- Description: The increase in use and production of engineered nanoparticles in recent years points towards their inevitable release into freshwater ecosystems. Subsequently, exposure to organisms in freshwater ecosystems is to be expected. The aim of this dissertation was to synthesize silver nanoparticles (AgNPs) using silver nitrate, gelatine and maltose as precursor, capping and reducing agent respectively. Cytotoxic effects of the as-synthesized AgNPs was evaluated at concentrations of 0.031 μg/L, 0.250 μg/L and 5.000 μg/L on selected target organs in zebrafish (Danio rerio ) after 96 hr of exposure, under a 24 hr static renewal system. Formation of AgNPs was investigated by UV-Vis spectrophotometry, which displayed absorption maxima peak characteristic of plasmon resonance band for silver at 419 nm. From transmission electron microscopy, AgNPs was found to be small, well dispersed and spherical in shape with a narrow size distribution, and an average particle size of3.76 ± 1.00 nm. Histopathological alterations following exposure to AgNPs was noticed in the gills, epidermis, muscle tissue and kidney. Secondary lamellae hypertrophy, oedema and epithelial lifting was observed in all experimental groups. Curling and clubbed tips of secondary lamellae were observed at the lowest concentration (0.031 μg/L). Hyperplasia and lamellae fusion was most common at the median concentration (0.250 μg/L) of AgNP exposure. Hypertrophy of endothelial cells along with blood vessel congestion was also observed. Reduced secondary lamellar length, lamellar erosion and thinning were observed at the highest concentration (5.000 μg/L).AgNP exposure also altered the shape of alarm cells. In addition, hyperplasia and hypertrophy of goblet cells were observed at the highest concentration (5.000 μg/L) at 96 hr. At 5.000 μg/L of AgNP, PAS reaction was intense (deep purple), while the number and size of these cells decreased. Staining with AB pH 2.5 demonstrated an intense deep purple staining at the lowest and at the median concentration (24 hr). Moderate staining was seen at the higher concentrations. Muscle bundles with severe oedema, their thickening and separation were more pronounced in all treated groups. Histopathological tubular deformation and mononuclear cell infiltration were observed in kidney tissues. In addition; an increase in melano‐macrophage aggregation intensity was identified on the 48 hr in the treated groups. An increase in tubular epithelial cell regeneration/ proliferation, resulting in production of new epithelial cells which was indicative of recovering of kidney tissues from AgNP induced injury at 96 hr of exposure. Results presented here shows that fish respond to the presence of AgNPs.
- Full Text:
- Date Issued: 2019
From frontier to midlands: a history of the Graaff-Reinet district, 1786-1910
- Authors: Smith, Kenneth Wyndham
- Date: 1976
- Subjects: Graaff-Reinet (South Africa) -- History
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2656 , vital:20313 , ISBN 0949980730
- Description: The study of local history in South Africa is still in its infancy and has not been accorded the same recognition as elsewhere. There is no convenient manual to guide the would-be local historian of the Cape. There are few models that provide an insight into the main problems encountered by the local historian of a Cape community. In such local histories as exist, attention has been focussed predominantly on the foundation and physical growth of towns, the naming of streets, the establishment of schools and hospitals. Many of these accounts were written for publicity purposes or to commemorate the founding of towns. Although there is no history of the Dutch Reformed Church in Graaff-Reinet, the history of local congregations of the Dutch Reformed Church has generally been well covered in the form of Gedenkboeke and other studies. These frequently have a particular relevance as many towns such as Burgersdorp and Colesberg were founded as a result of the initiative of the church. Preface. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1976
- Authors: Smith, Kenneth Wyndham
- Date: 1976
- Subjects: Graaff-Reinet (South Africa) -- History
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2656 , vital:20313 , ISBN 0949980730
- Description: The study of local history in South Africa is still in its infancy and has not been accorded the same recognition as elsewhere. There is no convenient manual to guide the would-be local historian of the Cape. There are few models that provide an insight into the main problems encountered by the local historian of a Cape community. In such local histories as exist, attention has been focussed predominantly on the foundation and physical growth of towns, the naming of streets, the establishment of schools and hospitals. Many of these accounts were written for publicity purposes or to commemorate the founding of towns. Although there is no history of the Dutch Reformed Church in Graaff-Reinet, the history of local congregations of the Dutch Reformed Church has generally been well covered in the form of Gedenkboeke and other studies. These frequently have a particular relevance as many towns such as Burgersdorp and Colesberg were founded as a result of the initiative of the church. Preface. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1976
Prevalence and molecular analysis of multidrug-resistant Acinetobacter baumannii in the extra-hospital environment in Mthatha, South Africa
- Adjei, Anane Yaw, Apalata, Teke, Vasaikar, Sandeep, Okuthe, Grace Emily, Songca, Sandile
- Authors: Adjei, Anane Yaw , Apalata, Teke , Vasaikar, Sandeep , Okuthe, Grace Emily , Songca, Sandile
- Date: 2019
- Subjects: Acinetobacter baumannii , Carbapenemase-encoding genes , Multidrug-resistance , ISAba1 , intI1
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/11260/2409 , vital:41457 , https://doi.org/10.1016/j.bjid.2019.09.004
- Description: The presence of Acinetobacter baumannii outside hospitals remains unclear. This study aimed to determine the prevalence of multidrug-resistance (MDR) A. baumannii in the extra-hospital environment in Mthatha, South Africa and to investigate the frequency of carbapenemase-encoding genes. Material and Methods: From August 2016 to July 2017 a total of 598 abattoir samples and 689 aquatic samples were collected and analyzed presumptively by cultural methods for the presence of A. baumannii using CHROMagarTM Acinetobacter medium. Species identification was performed by autoSCAN-4 (Dade Behring Inc., IL) and confirmed by the detection of their intrinsic blaOXA-51 gene. Confirmed MDR A. baumannii isolates were screened for the presence of carbapenemase-encoding genes, ISAba1 insertion sequence and integrase intI1. Results: In total, 248 (19.3%) Acinetobacter species were isolated. Acinetobacter. baumannii was detected in 183 (73.8%) of which 85 (46.4%) and 98 (53.6%) were recovered from abattoir and aquatic respectively. MDR A. baumannii was detected in 56.5% (48/85) abattoir isolates and 53.1% (52/98) aquatic isolates. Isolates showed high resistance to antimicrobials most frequently used to treat Acinetobacter infections such as piperacillin/tazobactam; abattoir (98% of isolates resistant), aquatic (94% of isolates resistant), ceftazidime (84%, 83%), ciprofloxacin (71%, 70%), amikacin (41%, 42%), imipenem (75%, 73%), and meropenem (74%, 71%). All the isolates were susceptible to tigecycline and colistin. All the isolates carried blaOXA-51-like. The blaOXA-23 was detected in 32 (66.7%) abattoir isolates and 11 (21.2%) aquatic isolates. The blaOXA-58-like was positive in 7 (14.6%) and 4 (7.7%) abattoir and aquatic isolates, respectively. Both groups of isolates lacked blaOXA-24-like, blaIMP-type, blaVIM-type, blaNDM-1, blaSIM, blaAmpC, ISAba1 and inI1. Isolates showed high level of Multiple Antibiotic Resistance Index (MARI) ranging from 0.20-0.52. Conclusion: Extra-hospital sources such as abattoir and aquatic environments may be a vehicle of spread of MDR A. baumannii strains in the community and hospital settings.
- Full Text:
- Date Issued: 2019
- Authors: Adjei, Anane Yaw , Apalata, Teke , Vasaikar, Sandeep , Okuthe, Grace Emily , Songca, Sandile
- Date: 2019
- Subjects: Acinetobacter baumannii , Carbapenemase-encoding genes , Multidrug-resistance , ISAba1 , intI1
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/11260/2409 , vital:41457 , https://doi.org/10.1016/j.bjid.2019.09.004
- Description: The presence of Acinetobacter baumannii outside hospitals remains unclear. This study aimed to determine the prevalence of multidrug-resistance (MDR) A. baumannii in the extra-hospital environment in Mthatha, South Africa and to investigate the frequency of carbapenemase-encoding genes. Material and Methods: From August 2016 to July 2017 a total of 598 abattoir samples and 689 aquatic samples were collected and analyzed presumptively by cultural methods for the presence of A. baumannii using CHROMagarTM Acinetobacter medium. Species identification was performed by autoSCAN-4 (Dade Behring Inc., IL) and confirmed by the detection of their intrinsic blaOXA-51 gene. Confirmed MDR A. baumannii isolates were screened for the presence of carbapenemase-encoding genes, ISAba1 insertion sequence and integrase intI1. Results: In total, 248 (19.3%) Acinetobacter species were isolated. Acinetobacter. baumannii was detected in 183 (73.8%) of which 85 (46.4%) and 98 (53.6%) were recovered from abattoir and aquatic respectively. MDR A. baumannii was detected in 56.5% (48/85) abattoir isolates and 53.1% (52/98) aquatic isolates. Isolates showed high resistance to antimicrobials most frequently used to treat Acinetobacter infections such as piperacillin/tazobactam; abattoir (98% of isolates resistant), aquatic (94% of isolates resistant), ceftazidime (84%, 83%), ciprofloxacin (71%, 70%), amikacin (41%, 42%), imipenem (75%, 73%), and meropenem (74%, 71%). All the isolates were susceptible to tigecycline and colistin. All the isolates carried blaOXA-51-like. The blaOXA-23 was detected in 32 (66.7%) abattoir isolates and 11 (21.2%) aquatic isolates. The blaOXA-58-like was positive in 7 (14.6%) and 4 (7.7%) abattoir and aquatic isolates, respectively. Both groups of isolates lacked blaOXA-24-like, blaIMP-type, blaVIM-type, blaNDM-1, blaSIM, blaAmpC, ISAba1 and inI1. Isolates showed high level of Multiple Antibiotic Resistance Index (MARI) ranging from 0.20-0.52. Conclusion: Extra-hospital sources such as abattoir and aquatic environments may be a vehicle of spread of MDR A. baumannii strains in the community and hospital settings.
- Full Text:
- Date Issued: 2019
A socio-economic survey of the Amatola Basin: interim report
- Bekker, S B, de Wet, Christopher J, Manona, Cecil W
- Authors: Bekker, S B , de Wet, Christopher J , Manona, Cecil W
- Date: 1981
- Subjects: Ciskei (South Africa) -- Rural conditions Agriculture -- South Africa -- Ciskei Middledrift (South Africa) Fingo (African people) Hlubi (African people) Agriculture -- South Africa -- Ciskei Amatola River Watershed (South Africa) -- Economic conditions Amatola River Watershed (South Africa) -- Social conditions
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2282 , vital:20272 , ISBN 0868100730
- Description: Early in 1981, Professor S. Bekker of Rhodes University was invited to attend a meeting of the Amatola Basin Steering Committee of the Agricultural and Rural Development Research Institute (ARDRI) at the University of Fort Hare. At this meeting, Professor Bekker was invited to undertake a socio-economic survey of the Amatola Basin. The Board of the Institute of Social and Economic Research at Rhodes University gave Professor Bekker permission in February 1981 to undertake the research project on condition that it was conducted in the fashion this Institute usually requires. It was subsequently agreed that the survey, known as 'Amatola Basin VII: Socio-economic survey', was to establish the basic demographic, kinship, consumption and employment patterns of the residents of the Amatola Basin. Practices and traditions related to dry land agriculture would also be identified , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1981
- Authors: Bekker, S B , de Wet, Christopher J , Manona, Cecil W
- Date: 1981
- Subjects: Ciskei (South Africa) -- Rural conditions Agriculture -- South Africa -- Ciskei Middledrift (South Africa) Fingo (African people) Hlubi (African people) Agriculture -- South Africa -- Ciskei Amatola River Watershed (South Africa) -- Economic conditions Amatola River Watershed (South Africa) -- Social conditions
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2282 , vital:20272 , ISBN 0868100730
- Description: Early in 1981, Professor S. Bekker of Rhodes University was invited to attend a meeting of the Amatola Basin Steering Committee of the Agricultural and Rural Development Research Institute (ARDRI) at the University of Fort Hare. At this meeting, Professor Bekker was invited to undertake a socio-economic survey of the Amatola Basin. The Board of the Institute of Social and Economic Research at Rhodes University gave Professor Bekker permission in February 1981 to undertake the research project on condition that it was conducted in the fashion this Institute usually requires. It was subsequently agreed that the survey, known as 'Amatola Basin VII: Socio-economic survey', was to establish the basic demographic, kinship, consumption and employment patterns of the residents of the Amatola Basin. Practices and traditions related to dry land agriculture would also be identified , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1981
Interactivity in online journalism: a case study of the interactive nature of Nigeria's online Guardian
- Authors: Folayan, Oluseyi Olukemi
- Date: 2004
- Subjects: Guardian (Nigeria) Online journalism Electronic publishing -- Nigeria Electronic newspapers -- Nigeria Electronic news gathering -- Nigeria Nigeria -- Newspapers
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:3429 , http://hdl.handle.net/10962/d1002883
- Description: Interactivity is a distinguishing feature of the online environment but online newspapers have been slow in recognising interactivity as an essential condition of effective Web communication. Existing research show online newspapers generally offer few and token interactive options. This research explored interactivity in online journalism using Nigeria's online Guardian as a case study exploring the nature, levels and utilisation of interactivity and interactive features on the site. This study found that few interactive options are offered in Nigeria's online Guardian and those interactive options on offer just produced an illusion of interactivity; it was apparent that little effort was made to give interactive options on the site the significant attention they deserve. The study highlighted the difference between the availability and use of interactive features on an online newspaper site: the mere presence of such features does not necessarily speak to the levels or nature of interactivity on the site. The difficulty in obtaining findings for the qualitative aspect of this study spoke significantly to the findings in light of the fact that these were attempts using interactive options provided by the newspaper site. They stress what relevant literature highlights: the mere presence of interactive features is not in itself interactivity . Factors contributing to the low levels of interactivity in Nigeria's online Guardian include lack of technical expertise plus human and financial resources and the persistence of a mindset that hinders the development and integration of new information communication technologies and interactivity in online journalism. Theoretically, the possibilities are vast but the likelihood of translating theory into reality appears slim. For Nigeria's online Guardian to become interactive in a participatory way, it must undergo changes and choices about values, goals and standards. There must be a shift in attitudes and approaches towards news-content production and delivery as well as the problematic commercial aspects of electronic publishing routines and the effect of such choices on management and newsroom organisation.
- Full Text:
- Date Issued: 2004
- Authors: Folayan, Oluseyi Olukemi
- Date: 2004
- Subjects: Guardian (Nigeria) Online journalism Electronic publishing -- Nigeria Electronic newspapers -- Nigeria Electronic news gathering -- Nigeria Nigeria -- Newspapers
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:3429 , http://hdl.handle.net/10962/d1002883
- Description: Interactivity is a distinguishing feature of the online environment but online newspapers have been slow in recognising interactivity as an essential condition of effective Web communication. Existing research show online newspapers generally offer few and token interactive options. This research explored interactivity in online journalism using Nigeria's online Guardian as a case study exploring the nature, levels and utilisation of interactivity and interactive features on the site. This study found that few interactive options are offered in Nigeria's online Guardian and those interactive options on offer just produced an illusion of interactivity; it was apparent that little effort was made to give interactive options on the site the significant attention they deserve. The study highlighted the difference between the availability and use of interactive features on an online newspaper site: the mere presence of such features does not necessarily speak to the levels or nature of interactivity on the site. The difficulty in obtaining findings for the qualitative aspect of this study spoke significantly to the findings in light of the fact that these were attempts using interactive options provided by the newspaper site. They stress what relevant literature highlights: the mere presence of interactive features is not in itself interactivity . Factors contributing to the low levels of interactivity in Nigeria's online Guardian include lack of technical expertise plus human and financial resources and the persistence of a mindset that hinders the development and integration of new information communication technologies and interactivity in online journalism. Theoretically, the possibilities are vast but the likelihood of translating theory into reality appears slim. For Nigeria's online Guardian to become interactive in a participatory way, it must undergo changes and choices about values, goals and standards. There must be a shift in attitudes and approaches towards news-content production and delivery as well as the problematic commercial aspects of electronic publishing routines and the effect of such choices on management and newsroom organisation.
- Full Text:
- Date Issued: 2004
Code of Conduct for Australian companies with interests in the Republic of South Africa
- Date: Mar 1987
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/118204 , vital:34607
- Description: This is the first report under the voluntary Code of Conduct for Australian companies in South Africa. It marks Australia's entry into an area of monitoring and public reporting where the United States of America, the European Community (particularly the United Kingdom) and Canada have had Codes of Conduct since 1976 to 1978. Each of the countries concerned has companies with investment in South Africa and a physical presence there - through subsidiaries that operate as part of South African industry and that employ South African workers, including black workers. The Codes are intended to secure that companies from outside South Africa do not, when employing non-white (and particularly black) workers in South Africa, exploit the apartheid system. On the contrary, the objective is to work towards the elimination of discrimination at the industrial level - in pay rates, opportunities and otherwise - and at the same time to try to imp rove the position of the employees outside the work place. Those who press for stronger sanctions against South Africa and for active disinvestment policies criticise the Codes as weak palliatives for apartheid. In past years that might have been charged more forcibly. Today the existence of the Codes does not seem to be affecting decisions on sanctions. And the converse also seems to be true; with the sanctions that are presently operating the Codes continue to operate. Of course, when companies do disinvest, the Codes have fewer companies to cover and could eventually wither on that account. To the extent, therefore, that the Codes operate on the fact of foreign companies being in South Africa, they could be thought inconsistent with any policy of rapid disinvestment. However, there are at present no such policies operating at the level of Governments. A question arising from that is whether foreign companies, if they do remain in South Africa, should be subject to Codes and to reports back home as to their conduct, it being recognised that those reports, depending on their content and their reception, may either quieten or stir pressures for further disinvestment.
- Full Text:
- Date Issued: Mar 1987
- Date: Mar 1987
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/118204 , vital:34607
- Description: This is the first report under the voluntary Code of Conduct for Australian companies in South Africa. It marks Australia's entry into an area of monitoring and public reporting where the United States of America, the European Community (particularly the United Kingdom) and Canada have had Codes of Conduct since 1976 to 1978. Each of the countries concerned has companies with investment in South Africa and a physical presence there - through subsidiaries that operate as part of South African industry and that employ South African workers, including black workers. The Codes are intended to secure that companies from outside South Africa do not, when employing non-white (and particularly black) workers in South Africa, exploit the apartheid system. On the contrary, the objective is to work towards the elimination of discrimination at the industrial level - in pay rates, opportunities and otherwise - and at the same time to try to imp rove the position of the employees outside the work place. Those who press for stronger sanctions against South Africa and for active disinvestment policies criticise the Codes as weak palliatives for apartheid. In past years that might have been charged more forcibly. Today the existence of the Codes does not seem to be affecting decisions on sanctions. And the converse also seems to be true; with the sanctions that are presently operating the Codes continue to operate. Of course, when companies do disinvest, the Codes have fewer companies to cover and could eventually wither on that account. To the extent, therefore, that the Codes operate on the fact of foreign companies being in South Africa, they could be thought inconsistent with any policy of rapid disinvestment. However, there are at present no such policies operating at the level of Governments. A question arising from that is whether foreign companies, if they do remain in South Africa, should be subject to Codes and to reports back home as to their conduct, it being recognised that those reports, depending on their content and their reception, may either quieten or stir pressures for further disinvestment.
- Full Text:
- Date Issued: Mar 1987
A multi-threading software countermeasure to mitigate side channel analysis in the time domain
- Authors: Frieslaar, Ibraheem
- Date: 2019
- Subjects: Computer security , Data encryption (Computer science) , Noise generators (Electronics)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/71152 , vital:29790
- Description: This research is the first of its kind to investigate the utilisation of a multi-threading software-based countermeasure to mitigate Side Channel Analysis (SCA) attacks, with a particular focus on the AES-128 cryptographic algorithm. This investigation is novel, as there has not been a software-based countermeasure relying on multi-threading to our knowledge. The research has been tested on the Atmel microcontrollers, as well as a more fully featured system in the form of the popular Raspberry Pi that utilises the ARM7 processor. The main contributions of this research is the introduction of a multi-threading software based countermeasure used to mitigate SCA attacks on both an embedded device and a Raspberry Pi. These threads are comprised of various mathematical operations which are utilised to generate electromagnetic (EM) noise resulting in the obfuscation of the execution of the AES-128 algorithm. A novel EM noise generator known as the FRIES noise generator is implemented to obfuscate data captured in the EM field. FRIES comprises of hiding the execution of AES-128 algorithm within the EM noise generated by the 512 Secure Hash Algorithm (SHA) from the libcrypto++ and OpenSSL libraries. In order to evaluate the proposed countermeasure, a novel attack methodology was developed where the entire secret AES-128 encryption key was recovered from a Raspberry Pi, which has not been achieved before. The FRIES noise generator was pitted against this new attack vector and other known noise generators. The results exhibited that the FRIES noise generator withstood this attack whilst other existing techniques still leaked out secret information. The visual location of the AES-128 encryption algorithm in the EM spectrum and key recovery was prevented. These results demonstrated that the proposed multi-threading software based countermeasure was able to be resistant to existing and new forms of attacks, thus verifying that a multi-threading software based countermeasure can serve to mitigate SCA attacks.
- Full Text:
- Date Issued: 2019
- Authors: Frieslaar, Ibraheem
- Date: 2019
- Subjects: Computer security , Data encryption (Computer science) , Noise generators (Electronics)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/71152 , vital:29790
- Description: This research is the first of its kind to investigate the utilisation of a multi-threading software-based countermeasure to mitigate Side Channel Analysis (SCA) attacks, with a particular focus on the AES-128 cryptographic algorithm. This investigation is novel, as there has not been a software-based countermeasure relying on multi-threading to our knowledge. The research has been tested on the Atmel microcontrollers, as well as a more fully featured system in the form of the popular Raspberry Pi that utilises the ARM7 processor. The main contributions of this research is the introduction of a multi-threading software based countermeasure used to mitigate SCA attacks on both an embedded device and a Raspberry Pi. These threads are comprised of various mathematical operations which are utilised to generate electromagnetic (EM) noise resulting in the obfuscation of the execution of the AES-128 algorithm. A novel EM noise generator known as the FRIES noise generator is implemented to obfuscate data captured in the EM field. FRIES comprises of hiding the execution of AES-128 algorithm within the EM noise generated by the 512 Secure Hash Algorithm (SHA) from the libcrypto++ and OpenSSL libraries. In order to evaluate the proposed countermeasure, a novel attack methodology was developed where the entire secret AES-128 encryption key was recovered from a Raspberry Pi, which has not been achieved before. The FRIES noise generator was pitted against this new attack vector and other known noise generators. The results exhibited that the FRIES noise generator withstood this attack whilst other existing techniques still leaked out secret information. The visual location of the AES-128 encryption algorithm in the EM spectrum and key recovery was prevented. These results demonstrated that the proposed multi-threading software based countermeasure was able to be resistant to existing and new forms of attacks, thus verifying that a multi-threading software based countermeasure can serve to mitigate SCA attacks.
- Full Text:
- Date Issued: 2019
Detection of extended spectrum beta‑lactamase genes in Pseudomonas aeruginosa isolated from patients in rural Eastern Cape Province, South Africa
- Mojisola C. Hosu, Sandeep D. Vasaikar,, Grace E. Okuthe, Teke Apalata
- Authors: Mojisola C. Hosu , Sandeep D. Vasaikar, , Grace E. Okuthe , Teke Apalata
- Date: 2021
- Language: English
- Type: Journal Article
- Identifier: http://hdl.handle.net/11260/4509 , vital:44128
- Description: The proliferation of extended spectrum beta-lactamase (ESBL) producing Pseudomonas aeruginosa represent a major public health threat. In this study, we evaluated the antimicrobial resistance patterns of P. aeruginosa strains and characterized the ESBLs and Metallo- β-lactamases (MBL) produced. Strains of P. aeruginosa cultured from patients who attended Nelson Mandela Academic Hospital and other clinics in the four district municipalities of the Eastern Cape between August 2017 and May 2019 were identified; antimicrobial susceptibility testing was carried out against thirteen clinically relevant antibiotics using the BioMérieux VITEK 2 and confirmed by Beckman autoSCAN-4 System. Real-time PCR was done using Roche Light Cycler 2.0 to detect the presence of ESBLs; blaSHV, blaTEM and blaCTX-M genes; and MBLs; blaIMP, blaVIM. Strains of P. aeruginosa demonstrated resistance to wide-ranging clinically relevant antibiotics including piperacillin (64.2%), followed by aztreonam (57.8%), cefepime (51.5%), ceftazidime (51.0%), piperacillin/tazobactam (50.5%), and imipenem (46.6%). A total of 75 (36.8%) multidrug-resistant (MDR) strains were observed of the total pool of isolates. The blaTEM, blaSHV and blaCTX-M was detected in 79.3%, 69.5% and 31.7% isolates (n = 82), respectively. The blaIMP was detected in 1.25% while no blaVIM was detected in any of the strains tested. The study showed a high rate of MDR P. aeruginosa in our setting. The vast majority of these resistant strains carried blaTEM and blaSHV genes. Continuous monitoring of antimicrobial resistance and strict compliance towards infection prevention and control practices are the best defence against spread of MDR P. aeruginosa.
- Full Text:
- Authors: Mojisola C. Hosu , Sandeep D. Vasaikar, , Grace E. Okuthe , Teke Apalata
- Date: 2021
- Language: English
- Type: Journal Article
- Identifier: http://hdl.handle.net/11260/4509 , vital:44128
- Description: The proliferation of extended spectrum beta-lactamase (ESBL) producing Pseudomonas aeruginosa represent a major public health threat. In this study, we evaluated the antimicrobial resistance patterns of P. aeruginosa strains and characterized the ESBLs and Metallo- β-lactamases (MBL) produced. Strains of P. aeruginosa cultured from patients who attended Nelson Mandela Academic Hospital and other clinics in the four district municipalities of the Eastern Cape between August 2017 and May 2019 were identified; antimicrobial susceptibility testing was carried out against thirteen clinically relevant antibiotics using the BioMérieux VITEK 2 and confirmed by Beckman autoSCAN-4 System. Real-time PCR was done using Roche Light Cycler 2.0 to detect the presence of ESBLs; blaSHV, blaTEM and blaCTX-M genes; and MBLs; blaIMP, blaVIM. Strains of P. aeruginosa demonstrated resistance to wide-ranging clinically relevant antibiotics including piperacillin (64.2%), followed by aztreonam (57.8%), cefepime (51.5%), ceftazidime (51.0%), piperacillin/tazobactam (50.5%), and imipenem (46.6%). A total of 75 (36.8%) multidrug-resistant (MDR) strains were observed of the total pool of isolates. The blaTEM, blaSHV and blaCTX-M was detected in 79.3%, 69.5% and 31.7% isolates (n = 82), respectively. The blaIMP was detected in 1.25% while no blaVIM was detected in any of the strains tested. The study showed a high rate of MDR P. aeruginosa in our setting. The vast majority of these resistant strains carried blaTEM and blaSHV genes. Continuous monitoring of antimicrobial resistance and strict compliance towards infection prevention and control practices are the best defence against spread of MDR P. aeruginosa.
- Full Text:
An assessment of the nutritional status of young black school children in the Albany Magisterial District, Eastern Cape
- Authors: Fincham, Robert John
- Date: 1981
- Subjects: Schools -- South Africa -- Grahamstown Africans -- Nutrition Nutrition surveys -- South Africa -- Eastern Cape Malnutrition -- South Africa -- Eastern Cape Children -- South Africa -- Nutrition
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2172 , vital:20262 , ISBN 0868100773
- Description: This working paper covers a survey conducted between 16 and 30 January 1980 of 3 171 black Sub A and Sub B pupils 8 years old or younger, at schools in both the rural and urban areas of the Albany Magisterial District, Eastern Cape. The survey, under the auspices of the Institute of Social and Economic Research (ISER), Rhodes University, was carried out as a result of a request from Dr J. D. Krynauw, Regional Director of Health Services in the Eastern Cape, to assess levels of nutrition of black children. Newspaper reports (see Appendix 1) of low levels of nutrition and high infant mortality rates among young black children in the Eastern Cape appeared to suggest a chronic nutritional situation, a situation not perceived as such by the Department of Health. A comprehensive pilot study was instituted on written request from Dr Krynauw in late October 1979. A report of the pilot study findings was presented in May 1980 to the Department of Health (Fincham, 1980). The present paper elaborates on that report and also includes analyses of data not presented before. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1981
- Authors: Fincham, Robert John
- Date: 1981
- Subjects: Schools -- South Africa -- Grahamstown Africans -- Nutrition Nutrition surveys -- South Africa -- Eastern Cape Malnutrition -- South Africa -- Eastern Cape Children -- South Africa -- Nutrition
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2172 , vital:20262 , ISBN 0868100773
- Description: This working paper covers a survey conducted between 16 and 30 January 1980 of 3 171 black Sub A and Sub B pupils 8 years old or younger, at schools in both the rural and urban areas of the Albany Magisterial District, Eastern Cape. The survey, under the auspices of the Institute of Social and Economic Research (ISER), Rhodes University, was carried out as a result of a request from Dr J. D. Krynauw, Regional Director of Health Services in the Eastern Cape, to assess levels of nutrition of black children. Newspaper reports (see Appendix 1) of low levels of nutrition and high infant mortality rates among young black children in the Eastern Cape appeared to suggest a chronic nutritional situation, a situation not perceived as such by the Department of Health. A comprehensive pilot study was instituted on written request from Dr Krynauw in late October 1979. A report of the pilot study findings was presented in May 1980 to the Department of Health (Fincham, 1980). The present paper elaborates on that report and also includes analyses of data not presented before. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1981