Department of Veterinary Public Health and Preventive Medicine, University of Abuja, Abuja, Nigeria*Correspondence: Tel.: +2348187384271; E-mail: seabalaka@yahoo.co.uk Abstract Escherichia coli infection was diagnosed in 5-week old broiler chickens raised intensively on a medium-sized commercial farm in Gaube-Kuje, Abuja, Nigeria. Signs of weakness, depression and inappetance with ruffled feathers and pasted vents were reportedly observed in affected birds within the flock. Detailed post mortem examinations revealed diffuse splenomegaly and hepatomegaly with multifocal greyish areas on their surfaces while the diffusely enlarged kidneys were congested with mottled pale appearance. Histopathologically, the liver of affected broilers showed diffuse congestion, multifocal coagulative necrosis and cellular infiltration. Generalized perivascular and inter-septal oedema and haemorrhage were observed in the lungs of affected broilers with generalized lymphocytic depletion within the spleen as well as locally extensive congestion and haemorrhage within the kidney, and cellular infiltration and necrosis within heart musculatures. Microbiological evaluation of liver samples yielded pure E. coli growth only. A diagnosis of colibacillosis, especially colisepticaemia, was made with appropriate treatment based on culture and sensitivity test result involving Levofloxacin (R) . The client was consequently advised to guard against possible predisposing factors as control and preventive measures for the disease outbreak on the farm.

Background. Aquatic pollution by heavy metals has become a global problem and is of great concern due to the detrimental effects on aquatic ecosystems and possible human uptake. Objectives. The present study aimed to evaluate tissue bioaccumulations of heavy metals and possible human health risks in addition to associated cellular damages in fish for sale in a fish market in Abuja, Nigeria. Methods. Clarias gariepinus sold at the Kado Fish Market in Abuja, Nigeria, in March–April 2017 and March–April 2018 were randomly purchased and sampled. The heavy metal contents of the sampled fish were assayed and used to assess the extent of potential health risks to human consumers. The extent of histopathological changes associated with the bioaccumulations in the sampled fish were also evaluated according to standard procedures. Results. Levels of most heavy metals were above permissible limits, except for lower levels of zinc (Zn) in liver and muscle and higher levels of lead (Pb) in muscle in the sampled fish. Similarly, significant (p<0.05) liver bioaccumulation occurred for Zinc (Zn), chromium (Cr), iron (Fe), and copper (Cu) compared to their levels in muscle. The total hazard index (non-cancer risk across all metals) was 0.0415, which is very low and acceptable. The cancer risks ranged between the acceptable values of 1.98 × 10−5 – 3.71 × 10−6. Associated histopathological changes, which occurred in the sampled fish, differed between the various assayed tissues. Conclusions. Most of the heavy metals were significantly bioaccumulated (p<0.05) and were above the permissible levels, particularly in liver samples. The levels of muscle heavy metal bioaccumulation in the sampled fish posed no apparent cancer or non-cancer health risks to human consumers. However, further efforts are needed to minimize heavy metal aquatic environmental pollution to safeguard the health of aquatic flora and fauna and human consumers because of the tendency of these pollutants to persist and bioaccumulate to toxic levels over time. Competing Interests. The authors declare no competing financial interests.

Prevalence and distribution of Shiga toxin-producing Escherichia coli (STEC) serogroups from the faecal samples of cattle and camels slaughter in Maiduguri abattoir and their antibiotic resistance profile of the isolates were determined. The highest prevalence (24%) was recorded in the month of September and more STEC isolates came from cattle than the camels. There was significant (P < 0.05) seasonal trend in the prevalence of STEC among cattle and camel with more cases recorded during the wet season. Although, the study did not demonstrate significant influence of sex from the various sources. The serogroups recorded in this study were O157, O26, O91, O103 and O111. There was no significant difference (P < 0.05) between the detection rates of serogroups. The serogroup O26 was significantly (P < 0.05) the most observed serogroup in both camels and cattle. None of the STEC isolates tested positive for the O45 serogroup. PCR assays shows that 50 (63.3%) of the 86 STEC isolates carried the stx2 gene, 34 (43%) possessed the stx1 gene, and 14 (16.3%) carried both stx1 and stx2 genes. Other genes detected include eae and ehlyA. The antimicrobial resistance among the STEC O157 and non-O157 isolates from cattle and camels in Maiduguri abattoir were very high and the STEC isolates were resistant to at least one or more of the antimicrobial agents tested. There was also multidrug resistance with the most frequent occurring patterns been ampicillin/nalidixic acid and tetracycline/trimethoprim. However, all the 79 isolates were sensitive to chloramphenicol, ceftazidime and ceftriaxone; therefore, these drugs could be drugs of choice in the treatment of STEC infections.

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