CTX-M-15-producing Klebsiella pneumoniae ST273 associated with nasal infection in a domestic cat.

OBJECTIVES: The aim of this study was to investigate the genetic context of expanded-spectrum ß-lactam resistance in a Klebsiella pneumoniae strain causing a hard-to-treat nasal infection in a domestic cat. METHODS: A K. pneumoniae isolate was recovered from a 4-year-old male cat hospitalised in a veterinary hospital in Paraíba, Northeastern Brazil. Following phenotypic confirmation of multidrug resistance by the disk diffusion method, the genome was sequenced using an Illumina MiSeq system. Multilocus sequence typing (MLST) and structural features related to antimicrobial resistance were determined by downstream bioinformatics analyses. RESULTS: The strain was confirmed as sequence type 273 (ST273) K. pneumoniae harbouring a variety of genes conferring antimicrobial resistance to phenicols tetracyclines, aminoglycosides, ß-lactams, fosfomycin, sulfonamides and quinolones. Two plasmids were identified. Plasmid p114PB_I co-harboured a set of plasmid-borne resistance genes [blaCTX-M-15, blaTEM-1, qnrS1, tetD, tetR, sul2, aph(6)-Id, aph(3'') and cat2]. Notably, the multiresistance region was characterised as a chimeric plasmid structure sharing high sequence homology with several plasmids from Enterobacteriaceae. The second plasmid (p114PB_II) was characterised as a plasmid present in many genomes belonging to K. pneumoniae. CONCLUSION: The genetic context of the plasmid sequences harboured by a veterinary pathogenic K. pneumoniae isolate reveals the high complexity of horizontal gene transfer mechanisms in the acquisition of antimicrobial resistance genes. The emergence, dissemination and evolution of antimicrobial resistance must be investigated from a One Health perspective.

Performance assessment of imported ELISA in the serodiagnosis of the enzootic bovine leukosis in herds of Pernambuco state, Brazil / Avaliação do desempenho de ELISA importado no sorodiagnóstico da leucose enzoótica bovina em rebanhos do estado de Pernambuco, Brasil

Enzootic bovine leukosis (EBL) is an infectious disease of cosmopolitan distribution and chronic character caused by a virus of the Retroviridae family, bovine leukemia virus (BLV). The epidemiological situation of EBL in Brazil has motivated studies to improve its diagnosis, based on the recommended serological techniques: agar gel immunodiffusion (AGID) and enzyme-linked immunosorbent assay (ELISA). This study was designed to evaluate the use of imported ELISA for the detection of BLV in dairy herds raised in Pernambuco, Brazil, comparing it to AGID. Blood serum samples from 327 dairy cattle from the state of Pernambuco were tested to AGID and the imported commercial ELISA CHEKIT-Leucose-serum, produced by the IDEXX® laboratory for the diagnosis of EBL. Discarding 25 inconclusive samples from one or both tests, 302 samples were analyzed, being 24.1% positive (73/302) in the AGID and 45% (136/302) in the ELISA, which compared to the AGID, a technique considered standard, presented sensitivity of 98.6%, specificity of 72% and Kappa coefficient of 0.55. The lack of agreement in the diagnostic methods was probably due to the high sensitivity of the ELISA, which makes it possible to detect antibodies even in situations with low serum levels. Although AGID has been shown to be an efficient test so far, in more advanced stages of an EBL control and eradication program, with low prevalence rates, ELISA will present better performance, due to its higher sensitivity, avoiding the permanence of animals that spread the disease in the herds.(AU)

A leucose enzoótica bovina (LEB) é uma doença infecciosa de distribuição cosmopolita e caráter crônico causada por um vírus da família Retroviridae, o vírus da leucemia bovina (VLB). A situação epidemiológica da LEB no Brasil vem motivando estudos para o aprimoramento do seu diagnóstico, tendo como base as técnicas sorológicas recomendadas: imunodifusão em gel de ágar (IDGA) e Enzyme-Linked Immunoabsorbent Assay (ELISA). Este estudo teve como objetivo avaliar o uso de ELISA importado para a detecção do VLB em rebanhos leiteiros criados em Pernambuco, Brasil, comparando-o ao IDGA. Amostras de soro sanguíneo de 327 bovinos leiteiros do estado de Pernambuco foram testadas para IDGA e ELISA comercial importado CHEKIT-Leucose-serum, produzido pelo laboratório IDEXX® para o diagnóstico da LEB. Descartadas 25 amostras inconclusivas de um ou ambos os testes, foram analisadas 302 amostras, sendo 24,1% positivas (73/302) na IDGA e 45% (136/302) no ELISA, que em relação à IDGA, técnica considerada padrão, apresentou sensibilidade de 98,6%, especificidade de 72% e coeficiente Kappa de 0.55. A falta de concordância entre os métodos diagnósticos deveu-se, provavelmente, à elevada sensibilidade do ELISA, que possibilita detectar anticorpos mesmo em situações com baixos teores séricos. Apesar da IDGA se mostrar até o momento um teste eficiente, em etapas mais avançadas de um programa de controle e erradicação da LEB, com baixos índices de prevalência, o ELISA apresentará melhor desempenho, por possuir maior sensibilidade, evitando-se a permanência de animais disseminadores da doença nos rebanhos.​(AU)