Characterization of methicillin-resistant coagulase-negative staphylococci in milk from cows with mastitis in Brazil

Staphylococci are one of the most prevalent microorganisms in bovine mastitis. Staphylococcus spp. are widespread in the environment, and can infect animals and humans as opportunistic pathogens. The objective of this study was to determine the frequency of methicillin-resistance (MR) among coagulase-negative staphylococci (CoNS) previously obtained from milk of mastitic cows in Brazil and to characterize the antimicrobial resistance phenotype/genotype and the SCCmec type of MRCoNS isolates. Identification of MRCoNS was based on both biochemical and molecular methods. Susceptibility testing for eleven antimicrobials was performed by disk-diffusion agar. Antimicrobial resistance genes and SCCmec were investigated by specific PCRs. Twenty-six MRCoNS were detected (20 % of total CoNS), obtained from 24 animals, and were identified as follows: S. epidermidis (7 isolates), S. chromogenes (7), S. warneri (6), S. hyicus (5) and S. simulans (1). All MRCoNS isolates carried mecA while the mecC gene was not detected in any CoNS. The SCCmec IVa was demonstrated in nine MRCoNS, while the remaining 17 isolates harbored non-typeable SCCmec cassettes. In addition to oxacillin and cefoxitin resistance, MRCoNS showed resistance to tetracycline (n = 7), streptomycin (n = 6), tobramycin (n = 6), and gentamicin (n = 4), and harbored the genes tet(K) (n = 7), str (n = 3), ant(4) (n = 6) and aac(6)-aph(2) (n = 4), respectively. In addition, seven strains showed intermediate resistance to clindamycin and two to streptomycin, of which two harboured the lnu(B) and lsa(E) genes and two the aad(E) gene, respectively. One isolate presented intermediate erythromycin and clindamycin resistance and harbored an erm(C) gene with an uncommon 89-bp deletion rendering a premature stop codon. MRCoNS can be implicated in mastitis of cows and they constitute a reservoir of resistance genes that can be transferred to other pathogenic bacteria. © 2014 Springer International Publishing

Pulmonary, microbiological and hematological changes in Crotalus durissus terrificus (Serpentes, Viperidae) parasitized by nematodes of the genus Rhabdias (Nematoda, Rhabdiasidae) Alterações Pulmonares, microbiológicas e hematológicas em Crotalus durissus terrificus (Serpentes, Viperidae) parasitadas pelos nematódeos do gênero Rhabdias (Nematoda, Rhabdiasidae)

This study reported the pulmonary, microbiological, and hematological alterations in Crotalus durissus terrificus parasitized by nematodes of the genus Rhabdias. Histological, microbiological, and hematological analysis were performed on parasitized (n=6) and non-parasitized (n=6) snakes. Granulocytic and mononuclear cell infiltrates in the pulmonary parenchyma and epithelium were also observed during the histological analysis of parasitized snakes. Microbiological analysis of parasitized animals revealed the following Gram-negative bacteria: Citrobacter divergens, Burkholderia cepacia, Stenotrophomonas maltophilia, Proteus vulgaris, Enterobacter sakazakii, Enterobacter ammnigenus, Pseudomonas aeruginosa, Pantoea sp. and Providencia rettgeri. In non-parasitized snakes, the following species were identified: B. cepacia, Pseudomonas fluorescens, and Acinetobacter baumanii. Increased levels of plasmatic protein, decreased lymphocyte counts, and normal red blood cell values were observed in parasitized animals.<br>Este trabalho relata as alterações pulmonares, microbiológicas e hematológicas em Crotalus durissus terrificus parasitadas pelo nematódeo do gênero Rhabdias. As análises histológicas, microbiológicas e hematológicas foram realizadas em serpentes parasitadas (n=6) e não parasitadas (n=6). Foram observados infiltrados de células granulocíticas e mononucleares no parênquima pulmonar durante a análise histopatológica das serpentes parasitadas. A análise microbiológica revelou as seguintes bactérias Gram-negativas; Citrobacter divergens, Burkholderia cepacia, Stenotrophomonas maltophilia, Proteus vulgaris, Enterobacter sakazakii, Enterobacter ammnigenus, Pseudomonas aeruginosa, Pantoea sp. e Providencia rettgeri. Nas serpentes não parasitadas foram identificadas: B. cepacia, Pseudomonas fluorescens e Acinetobacter baumanii. Nos animais parasitados observaram-se: aumento da concentração de proteína plasmática, diminuição da contagem de linfócitos, e valores normais de hematimetria