Characterization of high level ampicillin- and aminoglycoside-resistant enterococci isolated from non-hospital sources.

PURPOSE: High level ampicillin- and aminoglycoside-resistant enterococci are being increasingly reported from non-hospital sources. This study was carried out to characterize these strains from non-hospital sources in Nigeria. METHODOLOGY: A collection of Enterococcus faecium isolated from vegetables, soil, farm animals and manure and observed to be resistant to ampicillin (n=63) and gentamicin (n=37) discs, were screened for resistance to high levels of ampicillin and aminoglycoside using E-test strips. Putative high level ampicillin- and aminoglycoside-resistant strains were screened for pbp5 and aminoglycoside modifying enzyme genes, respectively, by PCR. The C-terminal region of the amplified pbp5 gene was also sequenced. RESULTS: Five (5/63) and thirty-five (35/37) of the ampicillin- and aminoglycoside-resistant strains were identified as high level ampicillin- and aminoglycoside-resistant E. faecium strains, respectively, based on the MIC results. The amplified pbp5 gene from the high level ampicillin-resistant isolates displayed 96-99 % nucleotide sequence similarity with the reference strains and three novel insertions (500Glu→Leu, 502Asp→Arg and 614Ile→Phe) in the amino acid sequence. Aminoglycoside modifying enzyme genes aac(6')-Ie-aph(2″) (100 %), aph(2')-Ic (88.8 %), aph(3')-IIIa (90 %) and ant(4')-Ia (40 %) were detected among the high level aminoglycoside-resistant isolates. CONCLUSION: This is the first report on the characterization of high level ampicillin- and aminoglycoside-resistant Enterococcus faecium among animals and vegetables in Nigeria. The results show that non-hospital sources can constitute a reservoir for potential dissemination of these strains and genes to humans via the food chain or by direct contact.

Serological prevalence of leptospirosis in cattle slaughtered in the Zango abattoir in Zaria, Kaduna State, Nigeria.

Leptospirosis is an occupational zoonosis caused by pathogenic leptospires. In this study, the presence and prevalence of antibodies specific to Leptospira spp. serovar Hardjo in 142 cattle slaughtered between June and July 2011 was investigated using the enzyme-linked immunosorbent assay (ELISA). Five (3.50%) of the 142 cattle sampled were seropositive for antibodies to Leptospira spp. serovar Hardjo. Despite the fact that there was no significant difference (p>0.05) in seropositivity between sexes and between breeds sampled, there was a significant difference (p<0.05) in sero-positivity between the different age groups examined. Leptospirosis is present in cattle slaughtered in the Zango abattoir; butchers and abattoir workers are exposed to infected animals and are at risk of being infected by Leptospira spp. serovar Hardjo.