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Background: Clostridioides difficile is the major cause of infectious nosocomial diarrhoea in industrialized nations. Data on the occurrence of C. difficile in Africa, ribotype (RT) distribution, antimicrobial susceptibility patterns and potential zoonotic transmission are scarce. Methods: 80 Zimbabwean C. difficile isolates from different sources (chicken [n = 30], soil [n = 21] and humans [n = 29]) were investigated using ribotyping, toxin gene detection, resistance testing, multiple-locus variable-number tandem repeat analysis (MLVA), and whole genome sequencing (WGS). Results: Among chicken isolates, the most common RTs were RT103 (6/30), RT025 (5/30) and RT070 (4/30). Within soil samples, RT025 and RT056 were most common (3/21 each). In contrast, the non-toxigenic RT084 was most frequently found in human isolates (4/29). Toxin genes were detected in only 19/29 human isolates. Susceptibility testing showed no resistance against metronidazole and vancomycin, and resistance against macrolides and rifampicin was scarce (3/80 and 2/80, respectively); however, 26/80 isolates showed moxifloxacin resistance. MLVA and WGS of strains with identical RTs stemming from different sources revealed clustering of RT025 and RT084 isolates from human und non-human samples. Conclusion: No “hypervirulent” strains were found. The detected clusters between human, chicken and soil isolates indicate ongoing transmission between humans and environmental sources and might point towards a zoonotic potential.

BACKGROUND Clostridium difficile is associated with nosocomial and community-acquired diarrhoea and pseudomembranous colitis in humans. Little information is available on the importance of C. difficile as a causative agent of diarrhoea in developing countries such as Zimbabwe. The current study was carried out to determine the prevalence of C. difficile in diarrhoeal stools of outpatients over 2 years of age presenting at healthcare centres in Harare, Zimbabwe, and to determine the antimicrobial susceptibility of the isolates. METHODS Toxigenic stool culture was used in this study. Diarrhoeal stool specimens were cultured for C. difficile, followed by direct immunoassay on colonies of positive cultures with significant growth to detect toxins A or B. RESULTS C. difficile was detected in 8.6% (n=23) of the 268 diarrhoeal stool specimens. All C. difficile isolates were susceptible to metronidazole, vancomycin, chloramphenicol and doxycyline, and resistant to clindamycin, ciprofloxacin, gentamicin and cefotaxime. About 70% of the isolates were resistant to co-trimoxazole. CONCLUSIONS C. difficile was observed to be an important diarrhoeal pathogen and metronidazole was effective in treating diarrhoea caused by the bacterium. Co-trimoxazole, which is widely used as prophylaxis against opportunistic infections in HIV/AIDS patients, was not very effective in preventing diarrhoea caused by C. difficile.

Thermophilic Campylobacter spp. are important causative agents of diarrhoeal disease in humans. Antimicrobial-resistant Campylobacter spp. that originate from poultry can enter the human food chain and result in resistant Campylobacter spp. in human infections. Campylobacter spp. were isolated from chicken faeces collected from chicken farms near Harare. Human isolates of Campylobacter spp. were obtained from clinical laboratories in Harare. The Campylobacter isolates were identifed by biochemical tests and tested for their susceptibility to antimicrobial drugs using the disc-diffusion method. A total of 77 human and 83 chicken isolates were characterised. C. jejuni was the most common in both humans (75.3%) and chickens (60.2%), followed by C. coli, which was detected in 19.5% of human and 28.9% of chicken isolates, and then C. lari, detected in 5.2% of human and 10.8% of chicken isolates. All the Campylobacter spp. from humans and chickens were susceptible to erythromycin and all isolates from the chick...

Clostridium difficile has been shown to be a nosocomial pathogen associated with diarrhoea and pseudomembranous colitis in hospitalised patients, but very little is known about its prevalence outside the hospital environment. The aim of this study was to determine the prevalence of C. difficile in faeces of domestic animals, soil and drinking water in a rural community. Water, animal faeces and soil were collected from homesteads in a rural community and the samples were cultured for C. difficile. Clostridium difficile isolates that produced toxins A or B were tested for their susceptibility to antimicrobial drugs. Clostridium difficile was isolated from 37.0% of 146 soil samples, 17.4% of 115 chicken faeces samples, 6.0% of 234 water samples and 4.3% of 161 faecal samples of other animals. Some of the C. difficile isolates from chickens (55.0%), soil (66.7%) and water (14.3%) were toxigenic. All toxigenic isolates were susceptible to metronidazole, vancomycin, doxycycline, chloramphenicol and tetracycline and all were resistant to cefotaxime, gentamicin, ciprofloxacin, norfloxacin and nalidixic acid. The results of the present study suggest that chickens kept by villagers are an important reservoir of C. difficile, which may act as a source of human infection.

The study was conducted to determine the prevalence of Salmonella enteritidis diarrhoea in an urban area in Zimbabwe. Stool specimens from people of all ages presenting at primary level health centres in Harare were investigated for S. enteritidis and other bacterial and parasitic enteric pathogens. The first 46 S. enteritidis isolates were phage-typed, and all isolates were tested for susceptibility to ampicillin (10 microg), chloramphenicol (30 microg), cotrimoxazole (25 microg), tetracycline (30 microg), gentamicin (10 microg), nalidixic acid (30 microg), ciprofloxacin (5 microg) and ceftriaxone (30 microg). S. enteritidis was isolated in 74 (1.8%) of 4155 stool specimens which represented 30.7% of all Salmonella species isolated. The most common S. enteritidis phage type was 4 (78.3%) followed by 7, 9 and 23 (8.7%, 2.2%, 2.2%, respectively) All S. enteritidis isolates were sensitive to gentamicin, ciprofloxacin and ceftriaxone. Less than 10% of the isolates were resistant to the other antimicrobials except ampicillin, to which 13.5% were resistant. One isolate was resistant to ampicillin, chloramphenicol, cotrimoxazole and nalidixic acid.

Clostridium difficile has been shown to be a nosocomial pathogen associated with diarrhoea and pseudomembranous colitis in hospitalised patients and the infection is believed to be acquired nosocomially. Community-acquired C. difficile-associated diarrhoea has also been reported. Recent studies have shown the occurrence of C. difficile in food animals which may act as a source of infection to humans. The aim of this study was to determine the occurrence of C. difficile in broiler chickens sold at market places in an urban area in Zimbabwe. Faeces of broiler chickens were collected from the cages at the market places and soils were collected from areas around the market places. The chicken faeces and soil samples were cultured for C. difficile. The C. difficile isolates were tested for toxins A or B production as well as for their susceptibility to antimicrobial drugs. C. difficile was isolated from 29.0% of 100 chicken faeces samples and 22.0% of 100 soil samples. Some of the C. difficile isolates from chickens (89.7%) and soils (95.5%) were toxigenic. All the isolates were susceptible to metronidazole, vancomycin, doxycycline, chloramphenicol and tetracycline. Over 70% of the isolates were susceptible to erythromycin, co-trimoxazole and ampicillin. They were all resistant to cefotaxime, gentamicin, ciprofloxacin, norfloxacin and nalidixic acid. The results of the present study suggest that broiler chickens sold at market places in the urban area are an important source of C. difficile, which may infect humans through consumption of chicken meat.

Mukumbi is a traditional Zimbabwean wine prepared from a fruit called mapfura by the Shona people of Zimbabwe and amaganu by the Ndebele. The majority of people in Africa call the tree marula (Sclerocarya birrea subspecies caffra). The survival of Salmonella group B, Salmonella enteritidis, Shigella sonnei and Shigella flexneri in unfermented and fermented mapfura (marula) juice (mukumbi) was investigated. It was found that within 30 min of inoculation, there were no longer any viable pathogens in the fermented mapfura juice whilst in the unfermented juice, more than 10(4) cfu/ml were still viable after 8 h. When lactic acid (0.25 mg/ml) was added to the unfermented mapfura juice, more than 10(4) cfu/ml were also still viable after 8 h but none were viable after 24 h. The fermented product, mukumbi, has a rapid antimicrobial effect against the pathogens as compared to the unfermented juice and is therefore safe from contamination with these pathogens. It appears thus that the death of the pathogens was due to other compounds besides the low levels of lactic acid.

The current interest in the use of traditional fermented and malted foods for weaning is their potential to reduce the transmission of bacterial enteric pathogens through contaminated weaning foods as well as improving the nutritional value of the foods. This study was carried out to investigate the potential use of traditional fermented and malted foods for weaning in rural areas. Information was obtained by interviewing randomly selected 150 rural women with children under five years old. Ninety seven percent of the women had knowledge of some traditional fermented foods. The commonest fermented foods known by the women were mahewu (traditional fermented and malted sour, non-alcoholic cereal gruel), sour milk and sour porridge. Most of the women indicated that mahewu (94%), sour milk, (87%) and sour porridge (71%) were consumed by all family members. The majority of the women gave the fermented foods to infants from the age of four months. Although most of the infants were introduced to the fermented and malted foods from the age of four months, the foods were not given to infants very often, with the exception of mahewu. The storage period of the fermented foods ranged from one to three days. The results of this study show that mahewu, sour milk and sour porridge have a potential for use as weaning foods if they are promoted.

The survival of strains of Campylobacter jejuni and enteropathogenic and enterotoxigenic (LT) Escherichia coli was investigated in mahewu, a traditional fermented cereal gruel. The mahewu was inoculated with 106 to 107 colony forming units of the bacterial cells per ml of the cereal gruel. None of the strains of C. jejuni were detected 30 min after inoculation. All the strains of E. coli were detected after 24 h in mahewu but did not show any increase in numbers of surviving cells. The enterotoxigenic E. coli strains showed a more marked decrease in numbers than did enteropathogenic E. coli strains during the 24 h period after inoculation in the mahewu. This suggests that mahewu has some antimicrobial qualities and is unlikely to play a major role in the transmission of these 2 enteric pathogens.

A survey of enteric pathogens in 143 children with diarrhoea, 116 age-matched controls and 524 asymptomatic people of all ages in a commercial farming area was carried out over a period of one year. Giardia lamblia was detected in 34% of the cases, 29% of the controls and 23% of asymptomatic people of all ages. Various bacterial pathogens (Campylobacter, Shigella, Salmonella and enteropathogenic Escherichia coli) were isolated from 23% of the cases and 15% of the controls. Enteropathogenic E. coli was isolated as frequently from the cases as from the controls and asymptomatic people of all ages.