Potentially zoonotic shiga toxin-producing Escherichia coli serogroups in the faeces and meat of food-producing animals in Ibadan, Nigeria.

Shiga toxin-producing Escherichia coli (STEC) are major food-borne pathogens associated with gastroenteritis and sometimes fatal haemolytic uraemic syndrome complication. Farm animals are asymptomatic carriers of STEC and contaminated meat is an important vehicle for zoonotic transmission from animals to humans. This study investigated the presence, virulence traits and antimicrobial susceptibility of seven potentially human pathogenic STEC serogroups (O157, O26, O91, O103, O111, O128 and O145) in the faeces and meat of food-producing animals in Ibadan, Nigeria. One hundred and fifty-four (7.3%) of 2133 samples were positive for STEC serogroups. The pathogens were detected in the faeces of cattle (15.2%), sheep (10.7%), goats (7.5%) and pigs (5.6%) as well as in beef (3.8%), goat-meat (1.7%) and pork (4.0%). All seven investigated STEC serogroups were found in cattle, all except O145 were found in sheep, three serogroups (O157, O26 and O111) were found in goats and three (O157, O111 and O128) in pigs. The rate of detection of each of the serogroups in all 2133 samples was: O157 (5.0%), O26 (0.2%), O91 (0.3%), O103 (0.3%), O111 (1.0%), O128 (0.2%) and O145 (0.1%). Of all 154 isolates, 11.0% had shiga toxin type 1 gene (stx(1)), 25.3% had stx(2) and 41.6% had stx(1)/stx(2); intimin gene (eaeA) was detected in 56.5% and enterohaemolysin gene (hlyA) in 75.3%. Among the O157 isolates, 24.5% were negative for stx genes but positive for eaeA and/or hlyA while 7.6% were negative for all four virulence genes. Fourteen different combinations of virulence genes were encountered but stx(1)/stx(2)/eaeA/hlyA combination was the most predominant. The percentage resistance of the isolates to the tested antimicrobial agents was: ampicillin (82.5%), chloramphenicol (42.9%), ciprofloxacin (22.1%), enrofloxacin (25.3%), nalidixic acid (37.7%), neomycin (24.0%), norfloxacin (20.8%), streptomycin (50.7%) and tetracycline (75.3%). One hundred and forty-eight (96.1%) of all 154 isolates were resistant to at least one of the tested antimicrobial agents while 69.5% were categorised as multi-drug resistant. Potentially pathogenic multi-drug resistant STEC isolates were recovered from the meat production chain in Nigeria. Unhygienic practices that predominate during slaughter and processing were observed to have contributed to faecal contamination and presence of STEC in meat.

Childhood Septicaemia Due To Salmonella Species in Ibadan, Nigeria

A cross sectional study to assess the incidence and antibiotic sensitivity patterns of Salmonella isolates in septicaemic children who were presented at the children's emergency unit and children out-patient clinic, University College Hospital, Ibadan was undertaken. A total of 442 samples from children (6months and 11 years) with the history of fever were investigated, using blood culture method. The frequency of 151 bacteria isolated, were as follows: Staphylococcus aureus 50 (33.1%), Escherichia coli 29 (19.2%), Salmonella typhi 19 (12.6%), Staphylococcus albus 14(9.3%), Klebsiella species 12(7.9%), Pseudomonas aeruginosa 10(6.6%), Enterococcus faecalis 9(5.9%), Salmonella paratyphi 6(3.9%) and Haemophilus species 2(1.3%). Septicaemia due to Salmonella speciesshowed the highestamongchildren aged5-11years bracket (56%), followed by 1-5 years group (36%); while those within 0-1 year group showed the lowest frequency of (8%). Inthe antibiotic sensitivity patterns of Salmonella typhi and Salmonella paratyphi, only Ceftriaxone showed 100% sensitivity in-vitro.While Gentamicin, Ofloxacin,Cefrazidime; Augmentin, Pefloxacin, Chloramphenicol, Amoxycillin, Cotrimoxazole showed varied sensitivity/resistance in descending order. These findings suggest an increasing resistance to the antibiotics commonly used for salmonellosis and the rate at which bacteria become resistant to antimicrobial agents is of public health concern. This calls for routine bacteriological culture and sensitivity test in the management of bacterial infections. Furthermore, the provision of adequate health care, wholesome water for drinking and domestic use by governments cannot be overemphasized