Characterization of Acinetobacter spp. from raw goat Milk / Caracterização de Acinetobacter spp. isolados de leite caprino cru

Goats milk has been suggested as an alternative to cows milk, being a better digestible and hypoallergenic option. However, the presence of contaminating bacteria may significantly affect the safety of the product. In this research, we reported the isolation and characterization of Acinetobacter spp. isolates from raw goat milk samples purchased in the state of Rio de Janeiro, Brazil. Twenty-one samples were analyzed and ten isolates of Acinetobacter spp. were obtained. Six were identified as A. guillouiae, three as A. ursingii, and one as A. bereziniae. These isolates were characterized and eight showed proteolytic activity, seven showed lipolytic activity, and five isolates were able to produce both enzymes. None of the isolates was biofilm producer. However, when the production of antibiotic resistance enzymes KPC and ESBL were investigated, all isolates presented ESBL-positive phenotype, while eight (80%) were KPC-positive. This research, therefore, demonstrated that raw goats milk can also be a source of Acinetobacter spp., which can produce important thermostable deteriorating enzymes and may play a role of reservoirs of antibiotic resistance genes.(AU)

O leite de cabra tem sido sugerido como alternativa ao leite de vaca, sendo uma opção com melhor digestibilidade e menor alergenicidade. No entanto, a presença de bactérias contaminantes pode afetar significativamente a segurança do produto. Neste trabalho, relatamos o isolamento e caracterização de Acinetobacter spp. isolados de amostras de leite cru de cabra adquiridas no Estado do Rio de Janeiro, Brasil. Vinte e uma amostras foram analisadas e dez isolados de Acinetobacter spp. foram obtidos, sendo seis identificados como A. guillouiae, três como A. ursingii e um como A. bereziniae. Estes isolados foram caracterizados e oito apresentaram atividade proteolítica, sete mostraram atividade lipolítica e cinco foram capazes de produzir ambas as enzimas. Nenhum dos isolados foi produtor de biofilme. No entanto, todos os isolados apresentaram fenótipo ESBL-positivo, enquanto oito (80%) foram positivos para KPC. Este trabalho demonstra, portanto, que o leite de cabra cru também pode ser uma fonte de Acinetobacter spp., que podem produzir enzimas deteriorantes termoestáveis e desempenhar, também, um papel de reservatórios de genes de resistência a antibióticos.(AU)

Performance of RESIST-3 O.K.N. K-SeT immunochromatographic assay for the detection of OXA-48 like, KPC, and NDM carbapenemases in Klebsiella pneumoniae in Turkey

In this study, the performance of the RESIST-3 O.K.N. K-SeT (Coris BioConcept, Gembloux, Belgium) immunochromatographic assay was evaluated in 132 Klebsiella pneumoniae comprising 102 carbapenem resistant and 30 carbapenem susceptible isolates. Genotypically known isolates of Gram negative bacteria (n = 22) including various species were also tested by the assay as controls. The isolates tested by the immunochromatographic assay and also were run PCR for bla KPC, bla IMP, bla VIM, bla NDM, and bla OXA-48. The rates of bla NDM, bla OXA-48, and bla KPC in carbapenem resistant isolates were found at 52.9%, 39.2%, and 2.0%, respectively. Both bla NDM and bla OXA-48 were found in six (5.9%) isolates. The results of the assay showed 100% concordance with those obtained by PCR in 132 K. pneumoniae. The agreement between the two methods was found to be identical at the isolate level. The assay also correctly detected all genotypically known isolates of Escherichia coli, Serratia marcescens, Citrobacter freundii, Enterobacter cloacae, K. pneumoniae carrying bla KPC, bla NDM, and/or bla OXA-48. On the other hand, the assay did not exhibit any cross-reaction in control isolates harboring bla IMP and bla VIM. We conclude that the RESIST-3 O.K.N. K-SeT is a reliable, rapid, and user friendly test and we recommend it for routine diagnostic laboratories.(AU)

Antimicrobial activity evaluation and comparison of methods of susceptibility for Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacter spp. isolates

The production of KPC (Klebsiella pneumoniae carbapenemase) is the major mechanism of resistance to carbapenem agents in enterobacterias. In this context, forty KPC-producing Enterobacter spp. clinical isolates were studied. It was evaluated the activity of antimicrobial agents: polymyxin B, tigecycline, ertapenem, imipenem and meropenem, and was performed a comparison of the methodologies used to determine the susceptibility: broth microdilution, Etest® (bioMérieux), Vitek 2® automated system (bioMérieux) and disc diffusion. It was calculated the minimum inhibitory concentration (MIC) for each antimicrobial and polymyxin B showed the lowest concentrations for broth microdilution. Errors also were calculated among the techniques, tigecycline and ertapenem were the antibiotics with the largest and the lower number of discrepancies, respectively. Moreover, Vitek 2® automated system was the method most similar compared to the broth microdilution. Therefore, is important to evaluate the performance of new methods in comparison to the reference method, broth microdilution.(AU)

Antimicrobial resistance in Enterobacteriaceae in Brazil: focus on -lactams and polymyxins

ABSTRACT During the last 30 years there has been a dissemination of plasmid-mediated -lactamases in Enterobacteriaceae in Brazil. Extended spectrum -lactamases (ESBL) are widely disseminated in the hospital setting and are detected in a lower frequency in the community setting. Cefotaximases are the most frequently detected ESBL type and Klebsiella pneumoniae is the predominant species among ESBL producers. Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae became widely disseminated in Brazil during the last decade and KPC production is currently the most frequent resistance mechanism (96.2%) in carbapenem resistant K. pneumoniae. To date KPC-2 is the only variant reported in Brazil. Polymyxin B resistance in KPC-2-producing K. pneumoniae has come to an alarming rate of 27.1% in 2015 in São Paulo, the largest city in Brazil. New Delhi metallo--lactamase was detected in Brazil in 2013, has been reported in different Brazilian states but are not widely disseminated. Antimicrobial resistance in Enterobacteriaceae in Brazil is a very serious problem that needs urgent actions which includes both more strict adherence to infection control measures and more judicious use of antimicrobials.

Antimicrobial resistance in Enterobacteriaceae in Brazil: focus on -lactams and polymyxins

During the last 30 years there has been a dissemination of plasmid-mediated -lactamases in Enterobacteriaceae in Brazil. Extended spectrum -lactamases (ESBL) are widely disseminated in the hospital setting and are detected in a lower frequency in the community setting. Cefotaximases are the most frequently detected ESBL type and Klebsiella pneumoniae is the predominant species among ESBL producers. Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae became widely disseminated in Brazil during the last decade and KPC production is currently the most frequent resistance mechanism (96.2%) in carbapenem resistant K. pneumoniae. To date KPC-2 is the only variant reported in Brazil. Polymyxin B resistance in KPC-2-producing K. pneumoniae has come to an alarming rate of 27.1% in 2015 in São Paulo, the largest city in Brazil. New Delhi metallo--lactamase was detected in Brazil in 2013, has been reported in different Brazilian states but are not widely disseminated. Antimicrobial resistance in Enterobacteriaceae in Brazil is a very serious problem that needs urgent actions which includes both more strict adherence to infection control measures and more judicious use of antimicrobials.(AU)

Superbactérias

Pode-se dizer que o mundo é das bactérias. No corpo humano há 39 trilhõesdelas, contra 30 trilhões de células humanas. Essa convivência geralmente é pacífica enada se percebe. Entre essas, há as denominadas superbactérias. São espécies normaiscomo a Escherichia coli ou Klebsiella pneumoniae que vivem em nosso corpo. O queelas têm de diferente são genes que as tornam resistentes aos antibióticos. Acarbapenemase é uma enzima que confere resistência aos antibióticos carbapenêmicosque são eficazes contra quase todas as bactérias. Essa enzima é que torna a KPC umasuperbactéria e sério problema de saúde pública.Bactérias como Klebsiella spp têm a capacidade de passar sua resistência paraoutras espécies mais perigosas. Um tipo de bactéria pode transferir seu superpoderpara outra completamente diferente. O que ocorre é a transferência de genes entre asdiferentes espécies de enterobactérias. Sabe-se que 80% dos antibióticos produzidos nosEUA são usados na criação de animais como bovinos, suínos e na avicultura parafrangos. Esses animais recebem ração contendo antibióticos como promotores decrescimento, para que cresçam mais rápido e sem doenças. O uso maciço dessesmedicamentos estimula o surgimento dessas superbactérias que podem infectarhumanos. É comum encontrar-se bactérias multirresistentes a vários antimicrobianos, oque tem dificultado a prática da terapêutica anti-infecciosa e

ISOLAMENTO DE BACTERIÓFAGOS LÍTICOS AMBIENTAIS E SUA ATIVIDADE CONTRA BACTÉRIAS MULTIRRESISTENTES DE IMPORTÂNCIA CLÍNICA

O controle de doenças infecciosas envolvendo bactérias resistentes aos antibióticos são um desafio constante e crescente, sendo necessários métodos alternativos para controlar esses microrganismos. Neste contexto, um método antigo e promissor, é o uso dos bacteriófagos, vírus que infectam e lisam procariotos. O objetivo desse trabalho foi isolar e identificar bacteriófagos líticos, avaliando sua atividade sobre bactérias de importância clínica, bem como frente àquelas que apresentam resistência aos antibióticos. Para isso, foi realizada coleta de amostra de água superficial, a partir da qual buscou-se o isolamento de fagos através do ensaio de placa de lise. Subsequentemente, foi realizada a análise da suscetibilidade dos fagos encontrados contra novos isolados bacterianos. Por fim, foi realizado o sequenciamento dos fagos ativos sobre as bactérias resistentes, com o intuito de verificar se eles já foram previamente descritos ou se são bacteriófagos inéditos; além disso, confirmou-se a capacidade lítica dos fagos. A partir da amostra coletada foi possível isolar bacteriófagos para as seguintes bactérias hospedeiras: Escherichia coli ATCC 13706, E. coli ATCC 25922, E. coli ESBL, Klebsiella pneumoniae KPC e K. pneumoniae ESBL. As placas de lise demonstraram morfologias variadas entre as bactérias utilizadas. O teste de suscetibilidade revelou que os fagos encontrados nas bactérias hospedeiras se diferem, além de mostrar que bacteriófagos de bactérias resistentes podem infectar outros isolados com o mesmo mecanismo de resistência. Os resultados deste estudo poderão fomentar a aplicabilidade dos fagos no controle de bactérias resistentes aos antibióticos.

The control of infectious diseases involving bacteria resistant to antibiotics is a constant and growing challenge, requiring alternative methods to combat these microorganisms. In this context, an old but promising alternative is the use of bacteriophages, viruses that infect and lyse prokaryotes. The objective of this study was isolate and identify lytic bacteriophages, evaluating their activity on bacteria of clinical importance, as well as against those that show resistance to antibiotics. For this, a surface water sample was collected, from which phage isolation was sought through the lysis plate assay. Subsequently, an analysis was made of the susceptibility of the phages found against new bacterial isolates. Finally, the last step consisted of genetic analysis by sequencing the active phages on resistant bacteria, in order to verify whether they have been previously described or whether they are new bacteriophages; in addition, the lytic capacity of the phages was confirmed. From the collected sample, it was possible to isolate bacteriophages for the following host bacteria: Escherichia coli ATCC 13706, E. coli ATCC 25922, E. coli ESBL, Klebsiella pneumoniae KPC and K. pneumoniae ESBL. The lysis plates showed varied morphologies among the bacteria used. The susceptibility test revealed that the phages found in the host bacteria differ, in addition showed that bacteriophages from resistant bacteria can infect other isolates with the same resistance mechanism. Through sequencing it was possible to determine important viral characteristics, such as proteins associated with the type of cycle carried out by the virus. The results of this study may promote the applicability of phages in the control of bacteria resistant to antibiotics.

KPC-2-producing Klebsiella pneumoniae in a hospital in the Midwest region of Brazil

The emergence of β-lactamase-producing Enterobacteriaceae in the last few decades has become major challenge faced by hospitals. In this study, isolates of Klebsiella pneumoniae carbapenemase-2 (KPC-2)-producing K. pneumoniae from a tertiary hospital in Mato Grosso do Sul, Brazil, were characterized. Bacterial identification was performed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF; Bruker Daltonics, Germany) mass spectrometry. The minimum inhibitory concentrations of carbapenems were determined using the agar dilution method as recommended by the Clinical Laboratory Standards Institute guidelines. Carbapenemase production was detected using the modified Hodge test (MHT) and polymerase chain reaction (PCR), followed by DNA sequencing. Of 360 (12.2%) K. pneumoniae isolates obtained between May 2009 and May 2010, 44 (12.2%) were carbapenem nonsusceptible. Of these 44 isolates, thirty-six K. pneumoniae isolates that were positive by MHT and PCR carried the blaKPC-2 gene. Thus, KPC-2producing Klebsiella pneumoniae has been present in a Brazilian hospital located in the Midwest region since at least 2009.(AU)

Molecular characterization of multidrug-resistant Klebsiella pneumoniae isolates

Klebsiella pneumoniae is an important cause of healthcare-associated infections worldwide. Selective pressure, the extensive use of antibiotics, and the conjugational transmission of antibiotic resistance genes across bacterial species and genera facilitate the emergence of multidrug-resistant (MDR) K. pneumoniae. Here, we examined the occurrence, phenotypes and genetic features of MDR K. pneumoniae isolated from patients in intensive care units (ICUs) at the First Affiliated Hospital of Xiamen University in Xiamen, China, from January to December 2011. Thirty-eight MDR K. pneumoniae strains were collected. These MDR K. pneumoniae isolates possessed at least seven antibiotic resistance determinants, which contribute to the high-level resistance of these bacteria to aminoglycosides, macrolides, quinolones and β-lactams. Among these isolates, 24 strains were extended-spectrum β-lactamase (ESBL) producers, 2 strains were AmpC producers, and 12 strains were both ESBL and AmpC producers. The 38 MDR isolates also contained class I (28/38) and class II integrons (10/38). All 28 class I-positive isolates contained aacC1, aacC4, orfX, orfX and aadA1 genes. β-lactam resistance was conferred through bla_SHV (22/38), bla_TEM (10/38), and bla_CTX-M (7/38). The highly conserved bla_KPC-2 (37/38) and bla_OXA-23(1/38) alleles were responsible for carbapenem resistance, and a gyrAsite mutation (27/38) and the plasmid-mediated qnrB gene (13/38) were responsible for quinolone resistance. Repetitive-sequence-based PCR (REP-PCR) fingerprinting of these MDR strains revealed the presence of five groups and sixteen patterns. ...(AU)

Caracterização de micro-organismos multirresistentes isolados do ambiente e colonizando humanos, cães e gatos em um hospital veterinário de ensino

Infecção hospitalar (IH) ou nosocomial é a infecção adquirida dentro do hospital e que não tenha relação com o motivo da internação do paciente, tendo como principais causadores as bactérias multirresistentes, sobretudo os Staphylococcus meticilina resistente (MRS), Enterococcus vancomicina resistente (VRE), bacilos Gram negativos (BGN) produtores de beta-lactamase de espectro estendido (ESBL) e os BGN produtores de carbapenemases (CP). Com isso, os objetivos do trabalho foram detectar os principais micro-organismos multirresistentes envolvidos em infecções hospitalares na medicina veterinária, além de apontar os principais pontos de contaminação do Hospital de Clínica Veterinária (HCV) do CAV-UDESC. As amostras do ambiente foram coletadas em um único dia em quadruplicata e das pessoas envolvidas na rotina do hospital foi realizado um swab nasal. Foram coletados swab nasal e retal dos animais que permanecerem internados no HCV por mais de dois dias no momento da admissão do paciente e no momento da alta do hospital. Após a coleta das amostras os micro-organismos multirresistentes que apresentaram crescimento e características fenotípicas de resistência foram identificados e submetidos ao teste de sensibilidade aos antimicrobianos e, posteriormente, a detecção dos principais genes de resistência através da técnica de PCR. Foram coletadas 106 amostras de animais, sendo 44,34% (9 gatos e 38 cães) positivas para bactérias produtoras de ESBL. A Escherichia coli foi a principal bactéria produtora de ESBL isolada (53,42%). O gene TEM exibiu a maior frequência em isolados produtores de ESBL. Enterococcus faecalis foi o VRE mais isolado dos animais (35,8%). Enterococcus foi identificado com a presença do gene vanA (52,54% - n = 31), do gene vanB (23,73% - n = 14), do vanC (20,34% - n = 12) e do gene vanE (3, 39% - n = 2). Dos 81 cães e 25 gatos (n=106), 49,38% (n=40) e 44% (n=11) respectivamente estavam colonizados por MRS, totalizando 51 animais (48,11%), assim como 90% (18/20) dos swabs nasais coletados das pessoas. Todos os MRS fenotipicamente identificados apresentaram o gene mecA. Foi possível identificar micro-organismos CP em 13,21% (n=14, sendo 13 cães e um gato). Foram detectados os genes KPC (3), NDM (7), SPM (3), OXA-48 (3) e os genes FOX (3), ACC (4) e ACT (3). Dos 39 locais do HCV que foram realizados coleta do ambiente, todos (100%) apresentaram ao menos um dos micro-organismos pesquisados. Dos 94 pools coletados, foi possível isolar MRS em 81,91% (n=77), VRE em 12,77% (n=12), ESBL em 62,77% (n=59) e CP em 24,47% (n=23).

Hospital-acquired infection (IH) or nosocomial infection is the infection acquired within the hospital and is unrelated to the reason for the patient's hospitalization. The main causes are multiresistant bacteria, especially methicillin resistant Staphylococcus (MRS), vancomycin resistant Enterococcus (VRE), Gram-negative bacilli (BGN) extended-spectrum beta-lactamase (ESBL) and carbapenemase-producing (CP). The aim of the study was to detect the main multiresistant microorganisms involved in hospital-acquired infections in veterinary medicine, as well as to identify the main contamination points of the Hospital de Clínica Veterinária (HCV) of the CAV-UDESC. The samples of the environment were collected in a single day in quadruplicate and of the people involved in the routine of the hospital a nasal swab was performed. Nasal and rectal swabs were collected from animals that remained hospitalized for more than two days at the time of admission and at hospital discharge. After the collection of the samples, the multiresistant microorganisms that presented growth and phenotypic characteristics of resistance were identified and submitted to antimicrobial susceptibility test and, later, the detection of the main resistance genes by PCR technique. A total of 106 animal samples were collected, 44.34% (9 cats and 38 dogs) positive for ESBL-producing bacteria. Escherichia coli was the major ESBL-producing bacterium isolated (53.42%). The TEM gene exhibited the highest frequency in ESBL-producing isolates. Enterococcus faecalis was the most isolated VRE of the animals (35.8%). Enterococcus was identified with the presence of the vanA gene (52.54% - n = 31), the vanB gene (23.73% - n = 14), the vanC gene (20.34% - n = 12) and the vanE gene (3.39% - n = 2). Of the 81 dogs and 25 cats (n = 106), 49.38% (n = 40) and 44% (n = 11) respectively were colonized by MRS, totaling 51 animals (48.11%) as well as 90% (18/20) of nasal swabs collected from people. All phenotypically identified MRSs had the mecA gene. It was possible to identify CP microorganisms in 13.21% (n = 14, 13 dogs and one cat). The KPC (3), NDM (7), SPM (3), OXA-48 (3) and FOX (3), ACC (4) and ACT (3) genes were detected. Of the 39 HCV sites that were collected from the environment, all (100%) presented at least one of the microorganisms researched. Of the 94 pools collected, it was possible to isolate MRS in 81.91% (n = 77), VRE in 12.77% (n = 12), ESBL in 62.77% (n = 59) and CP in 24.47% (n = 23).

MULTIRRESISTÊNCIA AOS ANTIMICROBIANOS E DETECÇÃO DOS GENES blaKPC, blaNDM e blaOXA-48 EM Klebsiella pneumoniae ISOLADAS DE MASTITE CLÍNICA BOVINA

Klebsiella pneumoniae são bactérias oportunistas encontradas no trato intestinal de animais e humanos, bem como no ambiente. Em animais de produção, o patógeno é causa importante de mastite clínica bovina e, em humanos, figura entre os patógenos mais frequentes envolvidos em infecções nosocomiais. A multirresistência dos isolados aos antimicrobianos convencionais é preocupação emergente em saúde animal e saúde pública. Atualmente, merece destaque os estudos com a produção de carbapenemases por K. pneumoniae, que são enzimas relacionadas a resistência aos antimicrobianos do grupo dos carbapenêmicos. O presente estudo investigou os escores de gravidade clínica de mastite (leves, moderados e graves), o período do ano (estações) de maior isolamento, a ocorrência de multirresistência dos isolados a 19 antimicrobianos (pertencentes a 10 grupamentos), bem como a presença dos genes blaKPC, blaNDM e blaOXA-48, associados a produção de carbapenemases, em 60 K. pneumoniae isoladas do leite de vacas com mastite clínica. Os casos ocorreram principalmente nos meses de verão (28/60=46,7%) e outono (24/60=40%). As informações sobre a gravidade clínica da mastite foram obtidas de 30 (50,0%) vacas, das quais 20 (66,6%) apresentaram casos de mastite leves (score 1), 8 (26,7%) moderados (score 2) e 2 (6,7%) graves (score 3). A maior sensibilidade dos isolados no teste de difusão com discos foi observada para marbofloxacino (100%), levofloxacino (95%), norfloxacino (93,3%), ceftriaxona (85%) e sulfametoxazole/trimetoprim (80%). Em contraste, alta resistência dos isolados foi observada para rifampicina (100%) e azitromicina (96,4%), com grande variedade de perfis de resistência. O índice de resistência múltipla aos antimicrobianos - IRMA (0,3) foi observado em 50,0% (30/60) dos isolados. No teste de difusão com discos para identificação fenotípica de K. pneumoniae produtores de carbapenemases foram encontrados 71,6% (43/60) parcialmente sensíveis e 11,7% (7/60) resistentes ao imipeném; 55,0% (33/60) parcialmente sensíveis e 3,3% (2/60) resistentes ao meropenem e 15% (9/60) parcialmente sensíveis ao ertapenem. Em contraste, nenhum isolado foi considerado produtor de carbapenemases no teste de concentração inibitória mínima com fitas impregnadas utilizando o imipeném, ertapenem e meropenem. A detecção molecular por PCR detectou 1,66% (1/60) dos isolados carreando blaKPC, 1,66% (1/60) blaNDM e 5% (3/60) blaOXA-48. Não foi observada associação estatística (P>0,05) entre as variáveis estações do ano de isolamento do patógeno, escores de gravidade clínica, resistência aos antimicrobianos, testes de difusão para identificação de produção de carbapenemases e detecção dos genes. A multirresistência aos antimicrobianos e a presença de genes produtores de carbapenemases em K. pneumoniae isolados de vacas com mastite reforça a preocupação, de âmbito mundial, com o crescimento da resistência bacteriana em isolados obtidos de animais domésticos, bem como a necessidade do uso racional de antimicrobianos no tratamento/profilaxia da mastite bovina. Na literatura consultada refere-se pela primeira vez na América do Sul, a detecção dos genes de resistência aos carbapenêmicos blaKPC, blaNDM e blaOXA-48 em K. pneumoniae isoladas de casos clínicos de mastite em vacas.

Klebsiella pneumoniae are opportunistic bacteria found in the intestinal tract of animals and humans, as well as in the environment. In livestock animals the pathogen is an important cause of bovine clinical mastitis, and in humans represent one of the most frequent pathogens involved in nosocomial infections. The pandemic scenario of multidrug resistance of the pathogen to conventional antimicrobials is an emerging concern in animal and humans. Currently, studies with the K. pneumoniae carbapenemase (KPC)-producing, which are enzymes related to resistance to antimicrobials, particularly of the carbapenemics group, deserve attention. The present study investigated the severity of clinical mastitis (mild, moderate and severe), occurrence of cases in different seasons, multidrug to 19 antimicrobials belonging to 10 groups, as well as the presence of the genes blaKPC, blaNDM and blaOXA-48 associated with the production of carbapenemases in 60 K. pneumoniae isolated from clinical mastitis in cows. The highest sensitivity of the isolates in the disk diffusion test was observed for marbofloxacin (100%), levofloxacin (95%), norfloxacin (93.3%), ceftriaxone (85%) and sulfamethoxazole / trimethoprim (80%). In contrast, the highest resistance of the isolates was observed for rifampicin (100%) and azithromycin (96.4%) with great variety of resistance profiles. The multiple antibiotic resistance (MAR) index (0.3) was observed in 50% (30/60) strains. In the disk diffusion test, which is used for phenotypic identification of the K. pneumoniae carbapenemase-producing bacteria, the findings among the total isolates were as follows: 71.6% (43/60) partially sensitive and 7 (11.7%) resistant to imipenem; 55% (33/60) were partially sensitive and 3.3 (2/60) resistant to meropenem; and 15% (9/60) were partially sensitive to ertapenem. In contrast, no isolates were carbapenemases-producing in the minimal inhibitory concentration test (MIC) using imipenem, ertapenem, and meropenem. PCR molecular detection of the three resistance genes revealed one (1.66%) isolated carrying blaKPC, one (1.66%) blaNDM, and three (5%) blaOXA-48. No statistical association (P>0,05) was observed between seasons, scores of clinical severities, multidrug resistance of isolates, diffusion disk test to carbapenemase-production, and detection of the genes studied. The multidrug resistance and the presence of K. pneumoniae carbapenemase(KPC)-producing isolated from cows with mastitis, highlights the global concern with the growth of antimicrobial resistance of bacteria from domestic animals, as well as the need for the rational use of antimicrobials in the treatment/prophylaxis of bovine mastitis. To our knowledge, the detection of the genes blaKPC, blaNDM and blaOXA-48 in K. pneumoniae isolated from clinical cases of bovine mastitis is reported for the first time in South America.

Superbactérias

Pode-se dizer que o mundo é das bactérias. No corpo humano há 39 trilhõesdelas, contra 30 trilhões de células humanas. Essa convivência geralmente é pacífica enada se percebe. Entre essas, há as denominadas superbactérias. São espécies normaiscomo a Escherichia coli ou Klebsiella pneumoniae que vivem em nosso corpo. O queelas têm de diferente são genes que as tornam resistentes aos antibióticos. Acarbapenemase é uma enzima que confere resistência aos antibióticos carbapenêmicosque são eficazes contra quase todas as bactérias. Essa enzima é que torna a KPC umasuperbactéria e sério problema de saúde pública.Bactérias como Klebsiella spp têm a capacidade de passar sua resistência paraoutras espécies mais perigosas. Um tipo de bactéria pode transferir seu superpoderpara outra completamente diferente. O que ocorre é a transferência de genes entre asdiferentes espécies de enterobactérias. Sabe-se que 80% dos antibióticos produzidos nosEUA são usados na criação de animais como bovinos, suínos e na avicultura parafrangos. Esses animais recebem ração contendo antibióticos como promotores decrescimento, para que cresçam mais rápido e sem doenças. O uso maciço dessesmedicamentos estimula o surgimento dessas superbactérias que podem infectarhumanos. É comum encontrar-se bactérias multirresistentes a vários antimicrobianos, oque tem dificultado a prática da terapêutica anti-infecciosa e