Antimicrobial Profiling of Bacteria Isolated from Fish Sold at Informal Market in Mufakose, Zimbabwe.

The number of infections caused by antibiotic resistant bacteria is rising worldwide. Fish from multisource pollution waters can harbour multidrug-resistant bacteria that can be disseminated to humans through eating or contact of contaminated fish. A cross-sectional study was carried out to (i) isolate and phenotypically identify bacteria from 36 fish samples from informal market in Mufakose, Harare, and (ii) determine the antibiotic sensitivity pattern of the isolated bacteria against ten available antibiotics (ampicillin 10 µg, gentamycin 30 µg, penicillin G 10 µg, erythromycin 15 µg, tetracycline 30 µg, kanamycin 30 µg, neomycin 10 µg, cloxacillin 5 µg, lincomycin 15 µg, and sulfamethoxazole 25 µg) using the Kirby-Bauer disk agar diffusion method. Eight bacterial genera were isolated and identified, and they were Escherichia, Aeromonas, Staphylococcus, Pseudomonas, Citrobacter, Klebsiella, Enterobacter, and Proteus. Among the isolates, Escherichia coli was isolated most frequently (44%) followed by Staphylococcus aureus (19%), Enterobacter aerogenes (7%), Aeromonas spp. (5%), Proteus mirabilis (5%), Citrobacter (5%), and coagulase-negative Staphylococci (5%) and the least frequent were Klebsiella (3%) and Pseudomonas (3%). All isolates were susceptible to gentamycin. Varying antibiotic resistance rates were observed to lincomycin (100%), ampicillin (81%), penicillin (67%), erythromycin (65%), tetracycline (63%), neomycin (61%), cloxacillin (43%), kanamycin (24%), and sulphamethoxazole (13%). All the isolates were multidrug-resistant (resistant to at 3 or more drugs tested) except Proteus mirabilis. Proteus mirabilis has multiple antibiotic resistance (MAR) index of 0.2, and the other isolated bacteria had MAR indexes greater than 0.2 ranging from 0.3 to 0.7. Those MAR indexes above 0.2 showed that the bacteria isolates are from a high risk source where antibiotics were frequently used, possibly from sewage effluents. Isolation of enteric bacteria such as Escherichia coli is an indication of faecal contamination, and this poses a high risk to animal and human health. These significant findings call for effective risk assessment models and management plans that protect human, animal, and environmental health.

Microbial quality of frozen Nile crocodile (Crocodylus niloticus) meat samples from three selected farms in Zimbabwe.

Microbial quality of frozen Nile crocodile (Crocodylus niloticus) meat from three farms in Zimbabwe was assessed based on 2051 samples collected for pre-export testing during 2006 to 2011. Data were perused by season and year in terms of aerobic plate (APC), coliform (CC), Escherichia coli (ECC) and Listeria monocytogenes (LMC) counts and the presence of Salmonella spp. The log10-transformed data were compared among the farms and seasons using the Kruskal-Wallis test. Microbial quality of the samples was graded based on the EC No. 2073.2005 criteria for beef. The mean APC and CC for the crocodile meat differed significantly (P=0.000) among the farms with the highest APC (3.2±0.05 log10 cfu/g) and the lowest (2.7±0.05 log10 cfu/g) recorded from farms A and C, respectively. There were no significant differences (P>0.05) in ECC and LMC among the farms, while Salmonella spp. were only isolated from one farm. Although the microbial quality of frozen crocodile meat from these farms was generally within acceptable limits, the isolation of E. coli and Salmonella spp. is of public health concern. Thus, implementing of measures to control the pasteurizing process and to minimize bacterial contamination of crocodile meat after pasteurization need to be carefully considered.

Detection of Brucella abortus in Chiredzi district in Zimbabwe.

Brucellosis is an endemic disease in Zimbabwe caused by the genus Brucella. Brucella seroprevalence was recently reported to be high in the wildlife-livestock interface in the Chiredzi district and the neighbouring Gonarezhou National Park (GNP) in Zimbabwe, and higher amongst communal cattle with an abortion history and access to grazing in GNP than amongst communal cattle with no abortion history or access to grazing in GNP. The aim of this study was to investigate Brucella species in brucellosis seropositive cattle in the Chiredzi district with access to GNP using isolation and identification. Isolation of Brucella species from whole blood (n = 18) and milk samples (n = 10) from seropositive animals with an abortion history was based on the rose Bengal test (RBT) and enzyme-linked immunoassays (enzyme- linked immunosorbent assay [ELISA]; indirect ELISA and complement ELISA), using microbiology and polymerase chain reaction (PCR) methods. Brucella abortus was cultured and identified from blood and milk collected from seropositive cows in both communal areas. The Brucella-specific 16-23S intergenic spacer (ITS) PCR and multiplex AMOS-PCR assays verified the identification of the cultures. Our results confirmed that B. abortus is present in cattle on communal farms in the Chiredzi district in Zimbabwe and might cause cattle abortions. The need for implementing control measures and raising public awareness on zoonotic transmission of brucellosis are recommended.