In vitro bioactivity of crude extracts of Lippia javanica on clinical isolates of Helicobacter pylori: preliminary phytochemical screening
- Authors: Nkomo, Lindelwa Precious
- Date: 2010
- Subjects: Extracts , Helicobacter pylori , Antibiotics , Drug resistance in microorganisms , Materia medica, Vegetable
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11257 , http://hdl.handle.net/10353/508 , Extracts , Helicobacter pylori , Antibiotics , Drug resistance in microorganisms , Materia medica, Vegetable
- Description: Helicobacter pylori classified as a class 1 carcinogen is a common human pathogen implicated in certain gastrointestinal diseases. Helicobacter pylori infection is acquired mainly in childhood, especially in developing countries. H. pylori infection causes peptic ulcer, duodenitis, gastritis and cancer. The growing resistance of H. pylori to antibiotics used in its treatment as well as other innate limitations of the triple therapy has necessitated a search for alternative treatment from natural sources which could be readily available, less cost effective. The antimicrobial activity of solvents (acetone, ethanol, methanol, chloroform and water) crude extracts of Lippia javanica were investigated against 31 H. pylori strains by the agar well diffusion technique. The minimum inhibitory concentration (MIC) was determined by spectrophotometric analysis at 620 nm using the broth micro dilution method and the rate of kill by broth dilution method. Phytochemical analysis was also performed. H. pylori standard strain NCTC 11638 was included as a positive control. Metronidazole and amoxicillin were used as positive control antibiotics. The ANOVA test was used to analyze the results using SPSS version 17.0. The strains were inhibited by all the extracts with inhibition zones of diameter ranging from 0-36 mm and 0-35 mm for the control antibiotic, clarithromycin. The MIC90 ranged from 0.039- 0.625 mg/mL for acetone; 0.039-1.25mg/mL for methanol, 0.00195-0.313 mg/mL for ethanol; 0.01975-2.5 mg/mL for metronidazole and 0.0048-2.5 mg/mL for amoxicillin. Acetone extract completely inhibited strain PE369C at MIC (0.1 mg/mL) and 2× MIC (0.2 mg/mL) in 18h and at ½× MIC (0.05 mg/mL) in 36h. Strain PE466C was completely inhibited at 4× MIC in 72h. Phytochemical analysis revealed the presence of flavonoids, saponins, tannins, steroids and alkaloids. The results indicate that the extracts of the leaves of L. javanica may contain compounds with anti-H. pylori activity and merits further study to identify the compounds.
- Full Text:
- Authors: Nkomo, Lindelwa Precious
- Date: 2010
- Subjects: Extracts , Helicobacter pylori , Antibiotics , Drug resistance in microorganisms , Materia medica, Vegetable
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11257 , http://hdl.handle.net/10353/508 , Extracts , Helicobacter pylori , Antibiotics , Drug resistance in microorganisms , Materia medica, Vegetable
- Description: Helicobacter pylori classified as a class 1 carcinogen is a common human pathogen implicated in certain gastrointestinal diseases. Helicobacter pylori infection is acquired mainly in childhood, especially in developing countries. H. pylori infection causes peptic ulcer, duodenitis, gastritis and cancer. The growing resistance of H. pylori to antibiotics used in its treatment as well as other innate limitations of the triple therapy has necessitated a search for alternative treatment from natural sources which could be readily available, less cost effective. The antimicrobial activity of solvents (acetone, ethanol, methanol, chloroform and water) crude extracts of Lippia javanica were investigated against 31 H. pylori strains by the agar well diffusion technique. The minimum inhibitory concentration (MIC) was determined by spectrophotometric analysis at 620 nm using the broth micro dilution method and the rate of kill by broth dilution method. Phytochemical analysis was also performed. H. pylori standard strain NCTC 11638 was included as a positive control. Metronidazole and amoxicillin were used as positive control antibiotics. The ANOVA test was used to analyze the results using SPSS version 17.0. The strains were inhibited by all the extracts with inhibition zones of diameter ranging from 0-36 mm and 0-35 mm for the control antibiotic, clarithromycin. The MIC90 ranged from 0.039- 0.625 mg/mL for acetone; 0.039-1.25mg/mL for methanol, 0.00195-0.313 mg/mL for ethanol; 0.01975-2.5 mg/mL for metronidazole and 0.0048-2.5 mg/mL for amoxicillin. Acetone extract completely inhibited strain PE369C at MIC (0.1 mg/mL) and 2× MIC (0.2 mg/mL) in 18h and at ½× MIC (0.05 mg/mL) in 36h. Strain PE466C was completely inhibited at 4× MIC in 72h. Phytochemical analysis revealed the presence of flavonoids, saponins, tannins, steroids and alkaloids. The results indicate that the extracts of the leaves of L. javanica may contain compounds with anti-H. pylori activity and merits further study to identify the compounds.
- Full Text:
Prevalence and risk factors for Helicobacter pylori transmission in the Eastern Cape Province application of immunological molecular and demographic methods
- Authors: Dube, Callote
- Date: 2010
- Subjects: Helicobacter pylori , Bacterial diseases , Gastritis -- Risk factors , Bacterial diseases -- Risk factors , Gram-negative bacteria , Gram-negative bacterial infections , Helicobacter , Helicobacter infections , Helicobacter pylori -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11262 , http://hdl.handle.net/10353/265 , Helicobacter pylori , Bacterial diseases , Gastritis -- Risk factors , Bacterial diseases -- Risk factors , Gram-negative bacteria , Gram-negative bacterial infections , Helicobacter , Helicobacter infections , Helicobacter pylori -- South Africa -- Eastern Cape
- Description: Helicobacter pylori (H. pylori) is a microaerophilic, Gram-negative motile curved rod that inhabits the gastric mucosa of the human stomach. The organism chronically infects billions of people worldwide and is one of the most genetically diverse of bacterial species. Infection with the organism potentially induces chronic gastritis and peptic ulcer disease. In addition, H. pylori plays a role in the etiology of gastric cancer and gastric MALT lymphoma. The risk of infection is increased in those living in the developing world, which has been ascribed to precarious hygiene standards, crowded households, and deficient sanitation common in this part of the world. Thus, the aim of this study was to identify the risk factors in the transmission of H. pylori in our environment, i.e. in Nkonkobe Municipality in the Eastern Cape Province, South Africa. Faecal samples were collected from 356 apparently healthy subjects, consisting of 168 males and 188 females aged from 3 months to 60 years (Mean = 31 years). A standardized questionnaire was applied, it described demographic characteristics including age, sex, household hygiene, socioeconomic status, area of residence, duration of stay in the area, sharing bath water, sharing tooth brush, habit of sucking thumb, medication currently being taken or medication taken within the past three months, source of water, type of toilet used, education and occupation. A sandwich-type enzyme immunoassay amplification technology (Amplified IDEIA TM Hp StAR TM , Oxoid, UK) was used to analyze the faecal samples for the detection of H. pylori antigens using monoclonal antibodies specific for H. pylori antigens. To assess the possibility of faecal oral route with tap water as an intermediary link, PCR targeting the ureC (glmM), a highly conserved gene in H. pylori ii was carried out to detect H. pylori DNA in faecal samples of already positive samples by HpSA test as well as in direct tap water used by the H. pylori positive subjects. QIAamp DNA stool mini kit was used to extract DNA from faecal samples. Tap water samples were then obtained using sterile bottles from areas inhabited by H. pylori positive subjects as determined by HpSA test and PCR. DNA extraction from water samples was done using UltraCleanTM Water DNA Isolation Kit (0.22μm) according to the manufacturer’s instructions. PCR with primers specific for H. pylori glmM gene was carried out with both positive and negative controls incorporated. Fisher’s exact test was used to assess the univariate association between H. pylori infection and the possible risk factors. Odds ratio (OR) and the corresponding 95 percent confidence interval (CI) were calculated to measure the strength of association using EPI INFO 3.41 package. P values of < .05 were required for significance. The precision rate of the diagnostic tests used was also determined. H. pylori antigen was detected in 316 of the 356 subjects giving an overall prevalence of 88.8 percent. Prevalence increased with age from 75.9 percent in children < 12 years age to 100 percent in the age group from 13 years to 24 years, also 100 percent prevalence of H. pylori was recorded in young adults aged 25-47 years and subjects aged 60 years (P < .05). H. pylori prevalence was higher in females than in males. Of 188 females who participated in the study, H. pylori antigen was detected in 172 (91.5 percent) versus 144 (85.7 percent) of 168 males (P > .05). Interestingly, H pylori antigen was detected more often (100 percent) in the high socioeconomic group than in those of low socioeconomic group (85.9 percent). Sixteen (66.7 percent) of twenty four faecal samples that had previously tested positive for the organism by HpSA test were confirmed positive by PCR. However none of the treated tap water samples tested positive for the organism by PCR. The present iii study revealed a high prevalence of H. pylori in faecal samples of asymptomatic individuals in the Nkonkobe Municipality, an indication of active infection. The obtained results also revealed that direct treated tap water might not be playing a crucial role in the oral transmission of H. pylori in the studied population.
- Full Text:
- Authors: Dube, Callote
- Date: 2010
- Subjects: Helicobacter pylori , Bacterial diseases , Gastritis -- Risk factors , Bacterial diseases -- Risk factors , Gram-negative bacteria , Gram-negative bacterial infections , Helicobacter , Helicobacter infections , Helicobacter pylori -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11262 , http://hdl.handle.net/10353/265 , Helicobacter pylori , Bacterial diseases , Gastritis -- Risk factors , Bacterial diseases -- Risk factors , Gram-negative bacteria , Gram-negative bacterial infections , Helicobacter , Helicobacter infections , Helicobacter pylori -- South Africa -- Eastern Cape
- Description: Helicobacter pylori (H. pylori) is a microaerophilic, Gram-negative motile curved rod that inhabits the gastric mucosa of the human stomach. The organism chronically infects billions of people worldwide and is one of the most genetically diverse of bacterial species. Infection with the organism potentially induces chronic gastritis and peptic ulcer disease. In addition, H. pylori plays a role in the etiology of gastric cancer and gastric MALT lymphoma. The risk of infection is increased in those living in the developing world, which has been ascribed to precarious hygiene standards, crowded households, and deficient sanitation common in this part of the world. Thus, the aim of this study was to identify the risk factors in the transmission of H. pylori in our environment, i.e. in Nkonkobe Municipality in the Eastern Cape Province, South Africa. Faecal samples were collected from 356 apparently healthy subjects, consisting of 168 males and 188 females aged from 3 months to 60 years (Mean = 31 years). A standardized questionnaire was applied, it described demographic characteristics including age, sex, household hygiene, socioeconomic status, area of residence, duration of stay in the area, sharing bath water, sharing tooth brush, habit of sucking thumb, medication currently being taken or medication taken within the past three months, source of water, type of toilet used, education and occupation. A sandwich-type enzyme immunoassay amplification technology (Amplified IDEIA TM Hp StAR TM , Oxoid, UK) was used to analyze the faecal samples for the detection of H. pylori antigens using monoclonal antibodies specific for H. pylori antigens. To assess the possibility of faecal oral route with tap water as an intermediary link, PCR targeting the ureC (glmM), a highly conserved gene in H. pylori ii was carried out to detect H. pylori DNA in faecal samples of already positive samples by HpSA test as well as in direct tap water used by the H. pylori positive subjects. QIAamp DNA stool mini kit was used to extract DNA from faecal samples. Tap water samples were then obtained using sterile bottles from areas inhabited by H. pylori positive subjects as determined by HpSA test and PCR. DNA extraction from water samples was done using UltraCleanTM Water DNA Isolation Kit (0.22μm) according to the manufacturer’s instructions. PCR with primers specific for H. pylori glmM gene was carried out with both positive and negative controls incorporated. Fisher’s exact test was used to assess the univariate association between H. pylori infection and the possible risk factors. Odds ratio (OR) and the corresponding 95 percent confidence interval (CI) were calculated to measure the strength of association using EPI INFO 3.41 package. P values of < .05 were required for significance. The precision rate of the diagnostic tests used was also determined. H. pylori antigen was detected in 316 of the 356 subjects giving an overall prevalence of 88.8 percent. Prevalence increased with age from 75.9 percent in children < 12 years age to 100 percent in the age group from 13 years to 24 years, also 100 percent prevalence of H. pylori was recorded in young adults aged 25-47 years and subjects aged 60 years (P < .05). H. pylori prevalence was higher in females than in males. Of 188 females who participated in the study, H. pylori antigen was detected in 172 (91.5 percent) versus 144 (85.7 percent) of 168 males (P > .05). Interestingly, H pylori antigen was detected more often (100 percent) in the high socioeconomic group than in those of low socioeconomic group (85.9 percent). Sixteen (66.7 percent) of twenty four faecal samples that had previously tested positive for the organism by HpSA test were confirmed positive by PCR. However none of the treated tap water samples tested positive for the organism by PCR. The present iii study revealed a high prevalence of H. pylori in faecal samples of asymptomatic individuals in the Nkonkobe Municipality, an indication of active infection. The obtained results also revealed that direct treated tap water might not be playing a crucial role in the oral transmission of H. pylori in the studied population.
- Full Text:
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