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

Analysis of the Outcomes of Tuberculosis Treatment and Factors Associated with Successful Treatment at the Bamenda Regional Hospital: A 10-year Retrospective Study.

BACKGROUND: Tuberculosis (TB) remains a global public health issue, impacting millions of people worldwide. This study determined the outcomes of TB treatment managed within a 10 year period at the Bamenda Regional Hospital in Cameroon. METHODS: A retrospective study was carried out among 2428 patients diagnosed and treated for active TB infection from 2013 to 2022, at the Bamenda Regional Hospital. Data collection was done from March to April 2023 using a data extraction form. Bivariate and multivariate logistic regression models were used to identify factors associated with successful TB treatment outcomes. Data was analyzed using SPSS software version 26. RESULTS: Of the 2428 patients with TB, 1380 (56.8%) were cured, 739 (30.4%) completed treatment, treatment failures were recorded in 10 (0.4%) patients, and 200 (8.2%) died during or after receiving treatment. Treatment default was the outcome in 99 (4.1%). Successful treatment outcomes were reported in 2119 (87.3%). Patients within age groups 41-50 (P = 0.010), 51-60 (P = 0.041), and >60 years (P = 0.006), male (P = 0.004), and human immunodeficiency virus-positive patients (P < 0.001) had decreased odds of successful treatment outcomes. CONCLUSION: The outcomes of treatment within a 10 year period showed that the treatment success was 2.7% below the World Health Organizations target. Prioritizing vulnerable patient groups in TB management and implementing public health interventions such as financial assistance and nutritional support will go a long way in improving treatment outcomes.

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

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.

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

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.

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

BACKGROUND: Very few studies have determined the prevalence and assemblage distribution of Giardia lamblia in South Africa. The present study aimed to ascertain the prevalence of G. lamblia 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 G. lamblia 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 Giardia infection (ᵡ2 = 10.533; p = .005). G. lamblia was significantly associated with watery stool types in females p = .008. Furthermore, a significant association was also noticed between the origin of samples (ᵡ2 = 9.725; p = .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 (p = .001) with the distribution of the pathogen with the stool type. The prevalence of Giardia 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 (p = .005). Genotyping revealed more G. lamblia 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 Giardia 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.

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

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

In this study, we report on the prevalence of 19 virulence genes in enteroaggregative Escherichia coli (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 aaiC or aatA genes. We investigated 177 enteroaggregative Escherichia coli isolates for the prevalence of virulence genes using multiplex polymerase chain reaction. The chromosomal gene aaiC was detected at higher frequency (48.0%) compared with aatA (26.0%). The gene encoding the open reading frame Orf61 was the most prevalent putative virulence trait detected among the isolates (150/177; 84.7%). None of the genes was statistically associated with diarrhea (P > 0.05). Detection rates were higher during 7-12 month of life with an association observed for the pic gene and the age group 7-12 months (P = 0.04). Winter was the season with the highest detection rates. Our data reveal a high prevalence of Orf61, Orf3, and astA in South African EAEC isolates. Specific genes may provide additional markers for the study of disease associations with age and season of sample collection.

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

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.

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

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.

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

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

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.

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

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.

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

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.