PATHOMORPHOLOGICAL CHANGES AND BACTERIAL PATHOGENS ASSOCIATED WITH SWINE PNEUMONIAS IN SOUTHWEST NIGERIA

Pneumonia is a major economic threat to swine industry worldwide, however, there is still dearth of information on the pathology and associated pathogens in Nigeria, and these were therefore investigated. Lungs from 408 slaughtered pigs were randomly collected from abattoirs in Abeokuta, Ibadan and Lagos. The lung samples were cultured for bacterial pathogens using standard techniques, while formalin-fixed tissues were processed for histopathological examination. Grossly, the most consistent lesion was bronchopneumonia (35.3%). The main histopathological findings were lymphoid hyperplasia of bronchus-associated lymphoid tissue (BALT) (88.2%), suppurative bronchopneumonia (63.6%), suppurative bronchitis and bronchiolitis with concurrent epithelial hyperplasia (57.1%), as well as thickened alveolar septa due to cellular infiltration consisting predominantly of neutrophils (54.1%). Ten different species of bacteria were isolated from the lung samples in which two or more pathogens were isolated from each sample (82.7%). Pasteurella multocida was the most frequently isolated bacterium (54.8%). Among the bacteria isolated, there were significant (P < 0.05) differences in the frequencies of isolation of β-haemolytic Streptococci, P. multocida, Haemophilus species and Escherichia coli between the pneumonic lungs and apparently normal lungs. The results of bacterial culture, gross and histopathological changes recorded in this study are consistent with bacterial pneumonia possibly caused by most of the bacteria identified in the present study.   &nbsp

ISOLATION METHODS FOR MOLECULAR DETECTION AND ANTIBIOTIC RESISTANCE PATTERN OF CAMPYLOBACTER SPP IN LAYER CHICKENS

This study was conducted to compare two culture methods for the isolation of Campylobacter spp from commercial layer chickens and subsequently confirmed by Polymerase Chain Reaction assays (PCR). Furthermore, the antimicrobial resistance profiles of PCR positive Campylobacter isolates were determined.Cloacal swab samples (550) from chickens randomly selected from five poultry farms in the four geographical zones in Ogun State were cultured for Campylobacter using modified charcoal Cefoperazone deoxycholate agar (MCCDA) and an improved culture method involving Preston broth pre-enrichment and subsequent subculture on Mueller Hinton agar with Campylobacter growth supplements. Putative isolates were later confirmed by PCR assay and sequencing analysis.Other isolates that grew on MCCDA and confirmed by sequencing analysis are Enterococcus faecalis, Escherichis coli, Comamonas kerstli and Pseudomonas aeroginusa . The antibiotic resistant profile of all the isolates were evaluated genotypically for resistance genes to tetracyclines (tetO), multiclasses (cmeB), aminoglycosides (aphA-3-1) and β-lactams (Blaoxa-61) using multiplex PCR (mPCR), and phenotypically for chlortetracycline, tylosin, streptomycin, ciprofloxacin and erythromycin resistance by microbroth dilution method which correspond to the antibiotic resistance genes. The apparent prevalence of Campylobacter was 16.8% by MCCDA while none of the isolates was positive to PCR. Meanwhile, prevalence rate of 26% was obtained using Preston broth pre-enrichment and Mueller Hinton agar with Campylobacter growth supplements, of which 11/50 (22%) of the isolates was confirmed positive by PCR. Genotypic characterization of PCR positive isolates showed 10/11(90%) were C. coli, 1/11(10%) other Campylobacter species and 0% C. jejuni. All the isolates carried both tetO and cmeB resistant genes. The results of minimum inhibitory concentration presented all PCR positive isolates had resistance of 10/10(100%), 9/10(90%), 6/10(60%), 9/10(90%), and 8/10(80%) to tetracycline, ciprofloxacin, erythromycin, spectinomycin and tylosin respectively. In addition, all isolates carried multiple resistance to most antibiotics tested which are commonly used in poultry practice in Nigeria. Campylobacter spp in the study areas showed diverse genotypic characteristics, and gene mediated multidrug resistance.   &nbsp

Prevalence and antibiotic resistance patterns of methicillin-resistant Staphylococcus aureus in raw milk and soft cheese (wara) sold in Abeokuta, Nigeria

The emergence of antibiotic-resistant bacteria in farm animals, their environment and food of animal origins is of significant potential public health importance. Methicillin resistant Staphylococcus aureus (MRSA) is an important opportunistic pathogen both in humans and in cattle. A total of 200 samples comprising of 100 each of raw milk and wara were collected from five different locations in Abeokuta, Ogun State. The samples were examined using standard bacteriological methods for the isolation and identification of Staphylococcus species including MRSA. Latex agglutination test of Penicillin-binding protein 2a (PBP2a) was used to further confirmed MRSA isolates. The susceptibility to antibiotics was determined by Kirby Bauer diffusion method. In all, S. aureus was detected in 52 (26%) of 200 samples of which 50 were confirmed as MRSA and two were Methicillin-sensitive Staphylococcus aureus (MSSA). Out of 50 MRSA isolates, 15 (15%) were from 100 raw milk and 35 (35%) were from 100 wara samples. The two MSSA isolates were from raw milk. The Staphylococcus aureus isolates from raw milk showed high resistance to ceftazidime 17 (100%), ampicillin 16 (94.1%), doxycycline 11 (64.7%), tetracycline 17 (100%), oxacillin 15 (88.2%), augmentin 17 (100%), gentamycin 15 (88.2%), colistin 15 (88.2%), and sulphamethoxazole 16 (94.1%). Isolates from wara were resistant to ceftazidime 35 (100.0%), ampicillin 35 (100%), doxycycline 15 (42.9%), tetracycline 23 (65.7%), oxacillin 35 (100.0%), streptomycin 20 (57.1%), augmentin 33 (94.3%), gentamycin 17 (48.6%), colistin 35 (100%), and sulphamethoxazole 27 (77.1%). The presence of MRSA in the raw cow milk and wara sold in Abeokuta may be due to overdependence on antibiotics in cattle production. Contamination along processing and marketing chain of wara due to unhygienic practices could also contribute to the presence of MRSA in the product. This constitutes a potential public health risk to consumers of milk and milk products in Abeokuta.Keywords: Antibiotics, Milk, MRSA, Resistance, Soft cheese, Unhygieni

Diverse non-typhoidal Salmonella serovars with multi-drug resistance potentials isolated from chicken faeces in Ogun State, Nigeria

This study was carried out in selected poultry farms to determine the prevalence, distribution and antimicrobial resistance patterns in Salmonella serovars in Ogun State, South-western Nigeria. A total of 200 faecal samples were aseptically collected from the four geographical zones of Ogun State, Nigeria. Seventy-eight Salmonella isolates spread across 39 serovars and representing a prevalence of 39% was recovered. Salmonella Urbana (n=7), Salmonella Kingston (n=6) and Salmonella Agama (n=5) serovars were more commonly isolated. Resistance was most common to ciprofloxacin (29.5%; n=23/78). Multi-drug resistance (MDR) was observed in 15.4% (n=12/78) of the isolates spread across 7 serovars: S. Kentucky, S. Telelkebir, S. Virchow, S. Blockley, S. Chomedey, S. Haifa, and S. Isangi. The study showed the diversity of Salmonella serovars and the increasing trend of antimicrobial resistance in poultry farms in Ogun State, Southwestern Nigeria