Publications by authors named "Nicoline Tanih"

16 Publications

  • Page 1 of 1

Molecular epidemiology of Microsporidia among HIV-positive and HIV-negative patients in the Limpopo province, South Africa.

J Infect Dev Ctries 2021 May 31;15(5):710-718. Epub 2021 May 31.

Department of Medical Laboratory Sciences, College of Health Sciences, University of Sharjah, Sharjah, United Arab Emirates.

Introduction: Human microsporidiosis represents an important and rapidly emerging opportunistic disease. The present study investigated the prevalence of microsporidia among HIV positive and HIV negative patients with or without diarrhoea in Vhembe and Mopani Districts in the Limpopo Province.

Methodology: A total of 170 stool samples were collected from these patients and microsporidia species was detected using a Real-Time PCR targeting a conserved region of the small ribosomal subunit rRNA (SSU-rRNA) gene of Enterocytozoon bieneusi, Encephalitozoon intestinalis, Encephalitozoon hellem, and Encephalitozoon cuniculi.

Results: Fifty six (32.9%) were positive for microsporidia. The prevalence was higher in HIV negative patients (36.6%) while 24.1% of patients who were HIV positive had microsporidia. Microsporidia was more common among patients aged between 1 and 10 years (52.6%). However among the HIV positive patients, microsporidia prevalence was higher among those that were not taking antiretrovirals (ARVs) compared to those who were on ARVs, (36.6%) and (24.1%), respectively. Microsporidia was also noted to be significantly associated with diarrheal and stomach pains; p = 0.02 and p = 0.048, respectively. Furthermore, microsporidia infections was more prevalent among patients who had animals at home (p = 0.037).

Conclusions: Study has shown a high prevalence of microsporidia among patients attending primary health centers in the Mopani District for the first time. Prevalence of microsporidia was higher among HIV negative and HIV positive patients who were not on ARV treatment. Keeping animals in the household appeared to be a risk of getting infected with microsporidia. Further studies are needed to determine the genetic characteristics of these organisms in the study population.
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http://dx.doi.org/10.3855/jidc.12988DOI Listing
May 2021

Prevalence and genetic characterization of in relation to diarrhea in Limpopo and Gauteng provinces, South Africa.

Parasite Epidemiol Control 2020 May 31;9:e00140. Epub 2020 Jan 31.

Deputy Pro Vice Chancellor Academics and Quality, Botho University, Botho Education Park, Kgale, Gaborone, Botswana.

Background: Very few studies have determined the prevalence and assemblage distribution of in South Africa. The present study aimed to ascertain the prevalence of infection and the spread of the various assemblages in two communities in South Africa - Giyani, Limpopo province (rural community) and Pretoria Guateng province (urban community).

Methods: Prevalence was determined by immunological and molecular methods analyzing a total of 516 stool samples collected from patients visiting different health centres in Giyani and Pretoria. For immunological assays, samples were screened by ELISA to detect antigen. Furthermore, a semi nested PCR amplifying the triose phosphate isomerase (tpi) gene was used to differentiate between the two most common human assemblages (A and B).

Findings: Of the 516 participants, 40 (7.75%) were identified as positive by ELISA. A statistically significant correlation was observed between the stool texture and infection (ᵡ = 10.533;  = .005). was significantly associated with watery stool types in females  = .008. Furthermore, a significant association was also noticed between the origin of samples (ᵡ = 9.725;  = .002). No significant correlation between age and gender was noted. Regarding the age groups, most people who were infected were between 3 and 20 years. A statistically significant association was seen ( = .001) with the distribution of the pathogen with the stool type. The prevalence of infection was higher in watery stool samples (71.4%) in Giyani region (rural) whereas in Pretoria, high prevalence was found in loose stool samples (6.2%). Generally, the distribution was statistically significant in the stool type collected for the study ( = .005). Genotyping revealed more assemblage B (17.8%) than assemblage A (1.7%). Furthermore, 21.0% of the samples exhibited single infection while 4.2% had mixed infections. Assemblage B was more common in Giyani than in urban Pretoria.

Conclusions: The study confirms as an important cause of diarrhea in the concerned communities with people in rural areas more at risk compared to those in urban areas with higher prevalence among younger patients. Therefore, health education campaigns should target young age groups.
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http://dx.doi.org/10.1016/j.parepi.2020.e00140DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7016452PMC
May 2020

Prevalence of Virulence Genes in Enteroaggregative Isolates from Young Children from Rural South Africa.

Am J Trop Med Hyg 2019 11;101(5):1027-1033

Department of Microbiology, University of Venda, Thohoyandou, South Africa.

In this study, we report on the prevalence of 19 virulence genes in enteroaggregative (EAEC) isolates from northern South Africa. Stool samples obtained prospectively from 97 children from 1 to 12 months of age were analyzed, and EAEC isolates were confirmed based on the presence of or genes. We investigated 177 enteroaggregative isolates for the prevalence of virulence genes using multiplex polymerase chain reaction. The chromosomal gene was detected at higher frequency (48.0%) compared with (26.0%). The gene encoding the open reading frame was the most prevalent putative virulence trait detected among the isolates (150/177; 84.7%). None of the genes was statistically associated with diarrhea ( > 0.05). Detection rates were higher during 7-12 month of life with an association observed for the gene and the age group 7-12 months ( = 0.04). Winter was the season with the highest detection rates. Our data reveal a high prevalence of , , and in South African EAEC isolates. Specific genes may provide additional markers for the study of disease associations with age and season of sample collection.
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http://dx.doi.org/10.4269/ajtmh.19-0192DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6838558PMC
November 2019

Helicobacter pylori in patients with gastritis in West Cameroon: prevalence and risk factors for infection.

BMC Res Notes 2018 Aug 3;11(1):559. Epub 2018 Aug 3.

Department of Microbiology and Parasitology, University of Buea, P. O. Box 63, Buea, Cameroon.

Objectives: Helicobacter pylori is a pathogenic bacterium that parasitizes the gastric mucous layer and the epithelial lining of the stomach causing duodenal ulcers, gastric ulcers and cardiovascular disease amongst others. This study aimed at establishing the epidemiologic profile of H. pylori infection in gastritis patients presenting at the Melong District Hospital.

Results: Blood, stool and epidemiological data collected from 500 patients were analyzed for the presence of H. pylori antibody in serum, antigen in stool and elucidation of risk factors captured in questionnaires. Of 500 blood samples, 217 (43.4%) were seropositive with male and female seroprevalences of 45.5% (61/134) and 42.6% (156/366) respectively. Similarly, 47.4% (237/500) samples tested positive for stool antigen with prevalences of 47.0% (63/134) for males and 47.5% (174/366) for females. The antigen prevalence was higher (53.2%; 118/222) in older patients (> 50 years) than in younger patients (42.8%; 119/278; P = 0.021). The antigen test had a higher (47.4%) prevalence than the antibody test (43.4%). Educational level, source of income, source of drinking water, age of patients, and alcohol consumption had positive associations with H. pylori infection. These results have clinical and epidemiological significance and call for intervention to mitigate the situation.
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http://dx.doi.org/10.1186/s13104-018-3662-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6076410PMC
August 2018

Evaluation of the tuberculosis control program in South West Cameroon: Factors affecting treatment outcomes.

Int J Mycobacteriol 2018 Apr-Jun;7(2):137-142

Department of Microbiology and Parasitology, Laboratory for Emerging Infectious Diseases, University of Buea; Department of Biomedical Sciences, Faculty of Health Sciences, Buea, Cameroon; Center for Tropical Diseases, University of Texas Medical Branch, Texas, USA.

Background: Tuberculosis (TB) has been ranked as one of the leading causes of death worldwide. In Cameroon, the National Tuberculosis Control Program aims to fight TB through the implementation of international directives (Directly Observed Treatment Short course [DOTS]). TB control program must reach global targets for detection (70%) and treatment success (85%) as stated by the United Nations Millennium Development Goals (MDGs). Implementing DOTS in Cameroon has not met the MDGs of 85% success rate. This study aimed at identifying factors affecting treatment success.

Methods: A cross-sectional retrospective study was used to collect data from 895 TB registers from January 2011 to December 2012. Out of the seven treatment centers in Fako Division, three were randomly selected following stratification into government, not-for-profit and for-profit structures. Descriptive statistics were used to obtain frequencies. Binomial logistics regression was used to obtain significant values for the various factors. Multinomial logistics was used on significant factors.

Results: Of the 895 registered TB patient records obtained, 416 (46.5%) patient were female and 479 (53.5%) patient were male. Characterizing TB patients, 510 (57.0%) were smear-positive pulmonary TB, 225 (25.1%) were smear-negative pulmonary TB, and 160 (17.9%) were extrapulmonary TB patients. Comparing treatment success rate (TSR) across the three centers, Baptist Hospital Mutengene had the highest value 94.97 (38%), followed by Regional Hospital Buea 83.74 (33%), and Central Clinic Tiko the least 73.13 (29%).

Conclusion: Patient registration year, treatment center, TB classification, and HIV status were identified to significantly affect TSR, hence, effectiveness of the TB program.
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http://dx.doi.org/10.4103/ijmy.ijmy_20_18DOI Listing
March 2019

Detection of pathogenic Escherichia coli and Staphylococcus aureus from cattle and pigs slaughtered in abattoirs in Vhembe District, South Africa.

ScientificWorldJournal 2015 24;2015:195972. Epub 2015 Feb 24.

HIV/AIDS & Global Health Research Programme, Department of Microbiology, University of Venda, Thohoyandou 0950, South Africa.

Pathogenic food-borne bacteria have been associated with severe morbidity and mortality in humans and animals. This study was aimed at determining the prevalence of Staphylococcus aureus, Salmonella spp., and Escherichia coli present in cattle and pigs slaughtered in selected abattoirs in Vhembe District and at determining the susceptibility of the isolates to antibiotics. A total of 176 swab samples (28 cattle and 16 pigs) of the rump, flank, brisket, and neck of the animals were analyzed using standard microbiological methods. E. coli isolates were genotyped to detect pathogenic strains. Of the 176 samples, 104 (67.5%) were positive for E. coli and 50 (32.5%) for S. aureus. There was no statistically significant difference (P > 0.05) in the isolation rate from the different animal parts or abattoirs. Overall, 14/104 (13.46%) of the E. coli isolates were pathogenic strains which included enteropathogenic E. coli (EPEC) (bfpA) 1.9%, enterotoxigenic E. coli (ETEC) (LT) 3.8%, and enteroaggregative E. coli (EAEC) (aaiC) 7.6%. E. coli isolates were resistant (100%) to vancomycin and bacitracin. S. aureus (100%) were resistant to oxacillin and nalidixic acid. The presence of resistant strains of these bacteria in food of animal origin could serve as important vehicles transmitting these bacteria to humans. This finding is of epidemiological significance.
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http://dx.doi.org/10.1155/2015/195972DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4354961PMC
April 2016

A comparative study of M.I.C evaluator test with the broth microdilution method for antimicrobial susceptibility testing of Enterobacter cloacae isolated from cooked food.

Pak J Pharm Sci 2014 Jan;27(1):63-6

Microbial Pathogenicity and Molecular Epidemiology Research Group, Department of Biochemistry and Microbiology, Faculty of Science and Agriculture, University of Fort Hare, P/Bag X1314, Alice, South Africa/Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon.

Agar dilution and broth microdilution are widely recommended quantitative antimicrobial susceptibility test methods, but they are tedious and time consuming to implement as routine tests in many clinical laboratories. Therefore, this study aimed at comparing the broth microdilution and the M.I.C Evaluator method which has been validated for its high accuracy and easy performance for routine diagnostic use. Twenty Enterobacter cloacae strains were isolated following microbiological procedures and confirmation of the isolates used the API 20E test. The strains were evaluated for their susceptibility to seven antimicrobials using the broth microdilution and MIC Evaluator methods. The doubling dilution difference (essential agreement) in the MIC result was derived from: log2 (MIC by BMD) -log2 (MIC by M.I.C Evaluator method). The categorical agreement, interpreted as breakpoints of sensitive and resistance strains was also noted. Categorical agreement between M.I.C Evaluator strip and broth microdilution for amoxicillin, metronidazole and erythromycin was 100%: while categorical agreement for ciprofloxacin was 90%. The essential agreement for erythromycin, ciprofloxacin and tetracycline were 90%, 70% and 15% respectively. Results indicate a high efficiency of the M.I.C Evaluator strip method in determination of minimum inhibitory concentration as compared to broth microdilution method. However, further analysis regarding the suitability of the M.I.C Evaluator for testing Enterobacter cloacae is warranted considering that no consensus guidelines exist for the use of this method with the organism.
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January 2014

Molecular Detection of Antibiotic Resistance in South African Isolates of Helicobacter pylori.

Gastroenterol Res Pract 2013 24;2013:259457. Epub 2013 Apr 24.

Department of Biochemistry and Microbiology, Faculty of Science and Agriculture, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa.

Rapid diagnosis and treatment of Helicobacter pylori (H. pylori) presents a challenge. We aimed at investigating the presence of H. pylori, susceptibility profile, and associated mutations in an effort to validate the effectiveness of GenoType HelicoDR assay in H. pylori typing in our environment. Two hundred and fifty-four biopsy specimens were cultured and DNA extracted from seventy-eight positive cultures using the Qiagen DNA extraction kit. The GenoType Helico DR which employs reverse hybridisation was used to confirm the presence of H. pylori, determination of its susceptibility to antimicrobials, and detection of mutations conferring resistance to clarithromycin and fluoroquinolones. The organism was isolated from 168/254 (66.1 %) of the specimens by culture. Of the 78 strains used for further investigation, 12/78 (15.38%) were resistant to clarithromycin while 66/78 (84.61%) were susceptible. For fluoroquinolone, 70/78 (89.74%) strains were susceptible while 8 (10.26%) were resistant. Mutations were observed in 17 strains with A2147G being the most prevalent; A2146C and D91N were the least. The reverse hybridisation assay is an easy and fast technique in confirming the presence of H. pylori, its antimicrobial profile, and associated mutations. Analysis regarding the suitability of this assay for H. pylori typing is warranted in other regions.
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http://dx.doi.org/10.1155/2013/259457DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3655586PMC
May 2013

The acetone extract of Sclerocarya birrea (Anacardiaceae) possesses antiproliferative and apoptotic potential against human breast cancer cell lines (MCF-7).

ScientificWorldJournal 2013 20;2013:956206. Epub 2013 Mar 20.

Department of Biochemistry and Microbiology, Faculty of Science and Agriculture, University of Fort Hare, P/Bag X1314, Alice 5700, South Africa.

Interesting antimicrobial data from the stem bark of Sclerocarya birrea, which support its use in traditional medicine for the treatment of many diseases, have been delineated. The current study was aimed to further study some pharmacological and toxicological properties of the plant to scientifically justify its use. Anticancer activity of water and acetone extracts of S. birrea was evaluated on three different cell lines, HT-29, HeLa, and MCF-7 using the cell titre blue viability assay in 96-well plates. Apoptosis was evaluated using the acridine orange and propidium iodide staining method, while morphological structure of treated cells was examined using SEM. The acetone extract exhibited remarkable antiproliferative activities on MCF-7 cell lines at dose- and time-dependent manners (24 h and 48 h of incubation). The extract also exerted apoptotic programmed cell death in MCF-7 cells with significant effect on the DNA. Morphological examination also displayed apoptotic characteristics in the treated cells, including clumping, condensation, and culminating to budding of the cells to produce membrane-bound fragmentation, as well as formation of apoptotic bodies. The acetone extract of S. birrea possesses antiproliferative and apoptotic potential against MCF-7-treated cells and could be further exploited as a potential lead in anticancer therapy.
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http://dx.doi.org/10.1155/2013/956206DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3616355PMC
September 2013

Current status of antibiograms of Listeria ivanovii and Enterobacter cloacae isolated from ready-to-eat foods in Alice, South Africa.

Int J Environ Res Public Health 2012 Aug 29;9(9):3101-14. Epub 2012 Aug 29.

Department of Biochemistry and Microbiology, Faculty of Science and Agriculture, University of Fort Hare, PMB X1314, Alice 5700, South Africa.

This study assessed the antimicrobial susceptibility of 51 Listeria ivanovii and 33 Enterobacter cloacae strains isolated from various ready-to-eat foods sold in Alice, South Africa. Isolates were identified using standard microbiological tests and further confirmed using API 20E and API Listeria kits. The disc diffusion technique was used to screen for antimicrobial susceptibility against 15 antimicrobials; minimum inhibitory concentration of five antibiotics was determined by the broth dilution method. All the strains of E. cloacae (100%) and 96% of L. ivanovii isolates were resistant to at least four or more of the antibiotics; nineteen antibiotypes were obtained based on the antibiotics used in the study. Antibiotype A5: AR PGR VAR ER APR was predominant in both L. ivanovii (23.5%) and E. cloacae (57.5%) isolates. Marked susceptibility of Listeria ivanovii was observed against chloramphenicol, ciprofloxacin, streptomycin and trimethoprim/sulfamethoxazole (100%) each while E. cloacae registered 100% susceptibility to ciprofloxacin only. Various percentages of susceptibility was reported to chloramphenicol and gentamicin (91%) each, nalidixic acid (97%) and streptomycin (94%). The MIC(90 )ranged from 0.004-7.5 µg/mL( )with E. cloacae being the most susceptible organism. The study demonstrated the presence of multi-resistant strains of bacteria in ready-to-eat-foods and speculates that these foods could serve as important vehicles transmitting multi-resistant bacteria to humans.
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http://dx.doi.org/10.3390/ijerph9093101DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3499856PMC
August 2012

Foodborne pathogens recovered from ready-to-eat foods from roadside cafeterias and retail outlets in Alice, Eastern Cape Province, South Africa: public health implications.

Int J Environ Res Public Health 2012 08 27;9(8):2608-19. Epub 2012 Jul 27.

Department of Biochemistry and Microbiology, Faculty of Science and Agriculture, University of Fort Hare, Alice 5700, South Africa.

This study assessed the microbiological quality of various ready-to-eat foods sold in Alice, South Africa. Microbiological analysis was conducted on 252 samples which included vegetables, potatoes, rice, pies, beef and chicken stew. The isolates were identified using biochemical tests and the API 20E, API 20NE and API Listeria kits; results were analyzed using the one-way-ANOVA test. Bacterial growth was present in all the food types tested; high levels of total aerobic count were observed in vegetables, 6.8 ± 0.07 followed by rice, 6.7 ± 1.7 while pies had the lowest count (2.58 ± 0.24). Organisms isolated included: Listeria spp. (22%), Enterobacter spp. (18%), Aeromonas hydrophila (12%), Klebsiella oxytoca (8%), Proteus mirabilis (6.3%), Staphylococcus aureus (3.2%) and Pseudomonas luteola (2.4%). Interestingly, Salmonella spp. and Escherichia coli were not isolated in any of the samples. There was a statistically significant difference (p < 0.05) in the prevalence of foodborne pathogens from hygienic and unhygienic cafeterias. The results indicated that most of the ready-to-eat food samples examined in this study did not meet bacteriological quality standards, therefore posing potential risks to consumers. This should draw the attention of the relevant authorities to ensure that hygienic standards are improved to curtain foodborne infections.
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http://dx.doi.org/10.3390/ijerph9082608DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3447576PMC
August 2012

Evaluation of the Acetone and Aqueous Extracts of Mature Stem Bark of Sclerocarya birrea for Antioxidant and Antimicrobial Properties.

Evid Based Complement Alternat Med 2012 17;2012:834156. Epub 2012 May 17.

Microbial Pathogenicity and Molecular Epidemiology Research Group, Department of Biochemistry and Microbiology, Faculty of Science and Agriculture, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa.

We assayed the antimicrobial activity of acetone and aqueous extracts of the stem bark of Sclerocarya birrea on some selected bacteria and fungi species including; Streptococcus pyogenes, Plesiomonas shigelloides, Aeromonas hydrophila, Salmonella typhimurium, Cryptococcus neoformans, Candida glabrata, Trichosporon mucoides, and Candida krusei using both agar well diffusion and minimum inhibitory concentration (MIC) assays. Based on the levels of activity, the acetone extract was examined for total polyphenolic content, radical scavenging and antioxidant activities. Total phenols of the extract were determined spectrophotometrically. The antioxidant activity was determined by the DPPH, ABTS and reducing power. All the bacteria and fungi species were susceptible to the plant extracts. The acetone extract was the most active for the bacterial species with MIC (0.156-0.625 mg/mL) while the aqueous extract was the most active for the fungi species with MIC (0.3125-1.25 mg/mL). The polyphenolic compounds were found as 27.2 mg/g tannic acid equivalent, 25.2 mg/g quercetin equivalent, 9.1 mg/g quercetin equivalent for phenols, flavonoid and flavonols respectively. The acetone extract exhibited a remarkable ability to scavenge radicals, strong reducing ability and a potential source of natural antioxidants. Both the acetone and aqueous extracts of S. birrea may provide a target for drug discovery.
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http://dx.doi.org/10.1155/2012/834156DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3363968PMC
August 2012

DNA sequence analysis of South African Helicobacter pylori Vacuolating Cytotoxin Gene (vacA).

Int J Mol Sci 2011 31;12(11):7459-68. Epub 2011 Oct 31.

Microbial Pathogenicity and Molecular Epidemiology Research Group, Department of Biochemistry and Microbiology, Faculty of Science and Agriculture, University of Fort Hare, P/Bag X1314, Alice 5700, South Africa; E-Mail:

Sequence diversity and population structures can vary widely among pathogenic bacteria species. In some species, all isolates are highly similar, whereas in others most of the isolates are distinguished easily. H. pylori is known for its wide genetic diversity amongst the various strains most especially in the genes involved in virulence. The aim of this study was to evaluate by PCR and sequence analysis, the genetic profile of H. pylori vacA gene (s1, s2, m1 and m2). We sequenced small DNA segments from 13 vacAs1, 10 vacAm2, 6 vacAm1 and 6 vacAs2 strains which were amplified with amplicon size of 259/286 bp, 290 bp and 352 bp for vacAs1/s2, m1 and m2 respectively. Based on similarities among our strains accession numbers were provided for seven vacAs1 (HQ709109-HQ709115), six vacAs2 (JN848463-JN848468), six vacAm1 (JN848469-JN848474) and six vacAm2 (HQ650801-HQ650806) strains. Amongst the strains studied, 98.07%, 98.58%, 97.38% and 95.41% of vacAs1, vacAs2, vacAm1 and vacAm2 of the strains were conserved respectively. Findings of this study underscores the importance of understanding the virulence composition and diversity of H. pylori in South Africa for enhanced clinico-epidemiological monitoring and pathophysiology of disease.
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http://dx.doi.org/10.3390/ijms12117459DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3233416PMC
December 2014

Prevalence of Helicobacter pylori vacA, cagA and iceA genotypes in South African patients with upper gastrointestinal diseases.

Acta Trop 2010 Oct 8;116(1):68-73. Epub 2010 Jun 8.

Microbial Pathogenicity and Molecular Epidemiology Research Group, Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X 1314, Alice 5700, South Africa.

Clinical response to Helicobacter pylori infection may be determined by specific virulence-associated genotypes which varies geographically. The aim of this study was to investigate the diversity of putative virulence markers of H. pylori; cagA, vacA and iceA in the Eastern Cape Province of South Africa. One hundred H. pylori strains obtained from dyspeptic patients were used. Gastric biopsies were obtained from 254 dyspeptic patients. H. pylori was cultured and strains were studied. Bacterial genotypes cagA, vacA (s and m subtypes) and iceA were analysed by PCR using specific primers. CagA was identified in 90% of the strains investigated. Fifty-eight of the 100 strains had the vacA signal sequence genotype s1 and 26 had subtype s2. Combined vacA s1/s2 was detected in 16 of the strains. VacA middle region analysis showed that 8 (8%) strains were m1 while 50 were m2. Combined vacA m1/m2 was detected in 36 of the strains. s1m2 (20%) and s2m2 (20%) genotypes were the most common allelic combinations of the vacA gene among the strains. Multiple vacA genotypes were detected in this study. Twenty-six percent of the strains identified had both iceA1 and iceA2. All our strains tested positive for the ureC (glmM) gene. This study reveals a high prevalence of vacA, cagA and iceA2.
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http://dx.doi.org/10.1016/j.actatropica.2010.05.011DOI Listing
October 2010

Marked susceptibility of South African Helicobacter pylori strains to ciprofloxacin and amoxicillin: clinical implications.

S Afr Med J 2010 Jan;100(1):49-52

Department of Biochemistry and Microbiology, University of Fort Hare, Alice, E Cape.

Objectives: Helicobacter pylori-associated infection is common in South Africa, as in other developing countries. Antibiotic resistance is recognised as a major cause of treatment failure. We studied the susceptibility and resistance patterns of H. pylori to guide empiric treatment and prevent the emergence of resistance.

Methods: Two hundred H. pylori strains obtained from gastric biopsies of patients presenting with gastric-related morbidities attending Livingstone Hospital, Port Elizabeth, were evaluated for their susceptibility to seven antibiotics - metronidazole, clarithromycin, tetracycline, amoxicillin, gentamicin, ciprofloxacin and erythromycin. H. pylori was isolated following standard microbiology procedures, and susceptibility determined using the Kirby-Bauer disc diffusion and agar dilution methods. Comparisons of antimicrobial resistance rates with sex of the patients were determined using the chi-square test; a p-value of <0.05 was considered significant.

Results: Marked susceptibility was observed for ciprofloxacin (100%) and amoxicillin (97.5%), and good activity for clarithromycin (80%) and gentamicin (72.5%). However, marked resistance (95.5%) was observed for metronidazole. The minimal inhibitory concentration (MIC) ranged from 0.0625 microg/ml to 8 microg/ml. The lowest MIC, with a range of 0.0625 - 1 microg/ml, was recorded for ciprofloxacin, while the highest (5 - 8 microg/ml) was noted for gentamicin.

Conclusion: Multidrug resistance was commonly encountered - a finding of clinical significance that calls for continuous surveillance of antibiograms to guide empiric treatment. We advocate the inclusion of ciprofloxacin in the treatment regimen of H. pylori infection in our study environment.
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January 2010

Phenotypic characterization of Salmonella typhimurium isolates from food-animals and abattoir drains in Buea, Cameroon.

J Health Popul Nutr 2009 Oct;27(5):612-8

Department of Biochemistry and Microbiology, Faculty of Science, University of Buea, PO Box 63, Buea, Cameroon.

Salmonella spp. have been extensively incriminated worldwide as common causes of bacterial gastroenteritis in humans, with food-animals serving as important reservoirs. The study was aimed at investigating cattle and pigs slaughtered in Buea as reservoirs of Salmonella Typhimurium and the susceptibility of isolates to antibiotics. In total, 230 specimens (comprising 50 each from the rectum, ileum, and gall bladder of cattle; and 10 each from same anatomical sites of pigs and 50 from abattoir drains) were analyzed for Salmonella using the standard microbiological, biochemical and serological techniques. Antibiotic susceptibility of the isolates was determined by the Kirby-Bauer disc-diffusion test. The isolates were characterized into biotypes using the API 20E kit, and results were analyzed using the chi-square test. Seventy-five (32.6%) of the 230 specimens were positive for S. Typhimurium, with pigs and abattoir drains presenting the highest level of isolation (40%). Biochemical typing grouped the isolates into five biotypes. Biotype I was the most prevalent (30.6%) while biotype IV was the least prevalent (9.3%) and was absent in samples from pigs. Antibiotic susceptibility studies revealed 14 antibiotypes based on antibiotics used in the study. The predominant antibiotype AMX DOX CEF was recorded in 13 (17.3%) of the isolates. Multidrug resistance (to four or more antibiotics) was recorded in 50.7% (38/75) of the isolates. The most active drugs were ciprofloxacin (98.6%), ofloxacin (93.3%), amikacin (90.6%), and gentamicin (84%). All the isolates (100%) were resistant to tetracycline and ampicillin. Cattle and pigs were found to be reservoirs of S. Typhimurium in the environment of Buea, Cameroon, implying that foods from these sources, if not properly handled, could serve as vehicles for its transmission to humans.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2928082PMC
http://dx.doi.org/10.3329/jhpn.v27i5.3637DOI Listing
October 2009
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