Multidrug-resistant Acinetobacter spp. from hospital intensive care units in Brazilian Amazon

Abstract Acinetobacter spp. are one of the main pathogens responsible for healthcare-associated infections and are associated with high rates of morbidity and mortality globally, mainly because of their high capacity to present and develop resistance to antimicrobials. To identify species of the Acinetobacter and their resistance profiles from samples collected from hospitalized patients, health professionals and hospital environmental sources in the intensive care units of different public reference hospitals in Porto Velho City, Rondônia, Western Brazilian Amazon. Isolates were identified using microbiological and molecular techniques. The antimicrobial susceptibility profile was determined by disk diffusion. A total of 201 Acinetobacter spp. isolates were identified, of which 47.3% originated from hospital structures, 46.8% from patients and 6% from healthcare professionals. A. baumannii and A. nosocomialis were the most prevalent, with frequency of 58.7% and 31.8%, respectively. Regarding the susceptibility profile, it was observed that 56.3% were classified as multidrug-resistant and 76.2% of the samples belonging to A. baumannii were resistant to carbapenems. In contrast, 96.9% were susceptible to polymyxin B and 91.3% to doxycycline. The data presented here can be used to guide and strengthen the control of multidrug-resistant infections caused by Acinetobacter spp., in addition to improving providing information from a traditionally unassisted region of Brazil.

Perfil microbiologico y de resistencia antimicrobiana en infecciones adquiridas en la comunidad. Hospital Universitario San José de Popayán / Microbiological profile and resistance spectrum of the community acquired bacterial infection of the San Jose Universitary Hospital in Popayan

Resumen Objetivo. Describir el perfil microbiológico y de resistencia bacteriana de los aislamientos en adultos con infecciones adquiridas en comunidad en el Hospital Universitario San José de junio 2016 a diciembre 2019. Metodología. Se realizó un estudio descriptivo de corte transversal, análisis retrospectivo de los aislamientos microbiológicos en adultos desde junio 2016 a diciembre 2019, basado en la data institucional. Se analizó la información con STATA15,0. Se obtuvo la aprobación del comité de ética del hospital. Resultados. Se incluyeron 5121 aislamientos microbiológicos, el 61% en el servicio de urgencias. El urocultivo fue la muestra más frecuente. Escherichia coli fue el germen más común tanto a nivel general como en urocultivos, hemocultivos y cultivos de líquido peritoneal. La resistencia a ampicilina y amp/sul fue elevada, hasta del 68% para E. coli. El 20% de los Staphylococcus aureus fueron resistentes a meticilina. Se observó una resistencia inusual a carbapenémicos por parte de Pseudomonas aeruginosa. Discusión. El perfil microbiológico concuerda con la literatura mundial y nacional, sin embargo, el HUSJ tiene un comportamiento microbiológico que debe ser estudiado a profundidad. Conclusión. Los porcentajes de resistencia a antibióticos de uso frecuente son elevados. Se requiere ajustes de las guías de manejo institucionales y nacionales.

Abstract Objetive. To describe the microbiological profile and resistance spectrum of the community acquired bacterial infection of the San Jose university hospital from june 2016 to december 2019 Methodology. A retrospective transverse descriptive study of microbial organisms found in adults in the institution from June 2016 to December 2019, the study is based in the hospital data. The analysis of the information was made with SATA 15.0. Results. 5121 samples were included, 61% from the emergency department. Urine culture was the most frequent sample taken. Escherichia coli was the most frequent isolated bacterial, in all samples, urine culture, blood culture, and peritoneal culture. Ampiciline r and ampiciline/sulbactam was high up to 68% of the E. Coli cultures. 20% of Staphylococcus aureus were methicillin resistant. Unusual carbapenemic resistance was found in the Pseudomona aeruginosa isolates.. Discussion. The data of the bacterial resistance spectrum Concord which was is found in the general medical literature, nevertheless the HUSJ, has a microbial behaviour that must be studied thoroughly. Conclusion. The antibiotic bacterial resistance to common used antibiotics is high. Adjustments are required in the instucional and national management guidelines

Perfil de resistência antimicrobiana de Klebsiella pneumoniae isoladas de animais domésticos e silvestres / Antimicrobial resistance profile of Klebsiella pneumoniae isolated from domestic and wild animals

Klebsiella pneumoniae é um patógeno oportunista, responsável por diversos tipos de infecções nosocomiais, e é considerado um microrganismo multirresistente. Dados na literatura que forneçam informações a respeito da resistência desse microrganismo a antimicrobianos em amostras de animais são escassos. Dessa forma, o objetivo deste trabalho foi avaliar o perfil e o seu aumento das resistências a antimicrobianos dentro da medicina veterinária. Um total de 67 isolados de K. pneumoniae, provenientes de diferentes sítios de isolamento de animais domésticos (39/67) e silvestres (28/67), foi confirmado por sequenciamento do gene 16S rRNA. O maior percentual de isolamento de K. pneumoniae foi de amostras de urina, com 16% (11/67), fezes, com 15% (10/67), e pulmão, com 13,5% (09/67). No perfil de resistência, foram testadas 11 categorias de antibióticos, sendo a maior taxa de resistência ao metronidazol 97% (65/67), à ampicilina 94% (63/67), à amoxicilina 93% (62/67), às sulfonamidas 93% (62/67), à colistina 93% (62/67) e à nitrofurantoína 88% (59/67). Aqueles que apresentaram menor taxa de resistência foram: meropenem 3% (2/67), imipenem 6% (4/67) e amicacina 16% (11/67). Todos os isolados foram considerados bactérias multirresistentes (MRD), com o índice de resistência múltipla aos antibióticos (IRMA) variando de 0,15 a 0,85 e com 60 tipos de padrões de resistência. O resultado deste estudo reforça que os animais são reservatórios de K. pneumoniae multirresistentes.(AU)

Klebsiella pneumoniae is an opportunistic pathogen responsible for several types of nosocomial infections and is considered a multiresistant microorganism. Data in the literature that provide information regarding the resistance of this microorganism to antimicrobials in animal samples are scarce. Thus, the objective of this work was to evaluate the profile and its increase of antimicrobial resistance within Veterinary Medicine. A total of 67 K. pneumoniae isolates from different domestic (39/67) and wild (28/67) isolation sites were confirmed by sequencing the 16S rRNA gene. The highest percentage of K. pneumoniae isolation was from urine samples with 16% (11/67), faeces 15% (10/67) and lung 13.5% (09/67). In the resistance profile, 11 categories of antibiotics were tested, with the highest resistance to metronidazole being 97% (65/67), ampicillin 94% (63/67), amoxicillin 93% (62/67), sulfonamides 93% (62 / 67), 93% colistin (62/67), and 88% nitrofurantoin (59/67). The ones with the lowest resistance were: meropenem 3% (2/67), imipenem 6% (4/67) and amikacin 16% (11/67). All isolates were considered multiresistant bacteria (MDR), with the Multiple Resistance to Antibiotics Index (IRMA) ranging from 0.15 to 0.85 and with 60 types of resistance patterns. The result of this study reinforces that the animals are reservoirs of multiresistant K. pneumoniae.(AU)

Carriage prevalence and drug resistance profile of MRSA and MSSA strains isolated from newborns / 中华疾病控制杂志

Objective To determine the carriage prevalence and antibiotics resistance profile of methicillin-resistant staphylococcus aureus(MRSA) and methicillin-sensitive staphylococcus aureus(MSSA) strains isolated from newborns. Methods A cross-sectional study was conducted in two hospitals in Shenzhen from August to November 2015. Cotton swab samples were collected from 1834 newborns. Staphylococcus aureus was identified by general laboratory tests, and antimicrobial-susceptibility profiles was tested. Results In total, 3.27% (60/1 834) Staphylococcus aureus (SA) strains were isolated, including 0.82% (15/1 834) MRSA and 2.45% (45/1 834) MSSA. Most MRSA and MSSA strains were resistant to penicillin and erythromycin but less than 10% strains resistant to linezolid. Drugs resistance rates of MRSA to erythromycin, moxifloxacin and clindamycin were all higher than that of MSSA (all P<0.05). The multidrug-resistant risk of MRSA (80.00%) was 12.36 times higher than that of MSSA (24.44%). Conclusions Multidrug-resistant SA especially MRSA strains isolated from newborns had the higher prevalence, the drugs resistance rate of MRSA strains was more serious than that of MSSA.

Ocorrência e perfil bacteriano de culturas coletadas em pacientes internados na unidade de terapia intensiva em um hospital terciário / Occurrence and bacterial profile of cultures collected from pa-tients admitted to the intensive care unit at a tertiary hospital

Introdução: O ambiente da UTI é considerado o foco das infecções relacionadas à assistência à saúde (IRAS). Isso deve-se a particularidades desse ambiente como a utilização de dispositivos invasivos, uso de imunossupressores, período de internação prolongado, colonização por micro-organismos resistentes, prescrição de antimicrobianos e a própria característica do ambiente da UTI, além da condição clínica do paciente. O conhecimento do perfil bacteriano de cada cultura norteia a equipe médica no tratamento inicial das infecções. Objetivo: O objetivo desse trabalho foi verificar a ocorrência e o perfil bacteriano presente em pacientes internados na UTI de um hospital universitário. Material e métodos: O estudo foi realizado através da análise de exames de secreções traqueais, hemoculturas e uroculturas de pacientes internados no período de janeiro a junho de 2018. Os dados foram coletados por meio de impressos laboratoriais do próprio serviço e tabulados na planilha do Excel®, sendo divididos em amostras positivas e negativas, e realizada análise descritiva com valores absolutos e percentuais. Resultados: Em geral, as bactérias de maior ocorrência foram Acinetobacter baumannii (20,3%), Pseudomonas aeruginosa (19,7%), Klebsiella pneumoniae (15,1%), Staphylococcus aureus (11,9%), Staphylococcus coagulase negativa (7,2%) e Escherichia coli (5,7%). As espécies bacterianas com maior resistência foram Acinetobacter baumanni, Klebisiella pneumoniae, Pseudomonas aeruginosa, Eschericia coli, Serratia marcencens e Enterobacter cloacae. Conclusão: Os dados deste trabalho permitem o conhecimento do perfil bacteriano encontrado nos pacientes internados, o que poderá nortear o tratamento das infecções e consequentemente diminuir a seleção de bactérias multirresistentes, auxiliando na prevenção e no controle das infecções hospitalares.

Introduction: The ICU environment is considered the focus of Healthcare-related health related infections (IRAS). This is due to the particularities of this environment such as the use of invasive devices, use of immunosuppressants, prolonged hospitalization, colonization by resistant microorganisms, antimicrobial prescribing and the very characteristic of the ICU environment, in addition to the clinical condition of the patient. Knowledge of the bacterial profile of each culture guides the medical team in the initial treatment of infections. Objective: The objective of this study was to verify the incidence incidence and the bacterial profile present in ICU patients of a University Hospital. Material and methods: The study was performed through the analysis of tracheal secretions, blood cultures and urocultures examinations of patients hospitalized from January to June 2018. Data were collected by means of laboratory forms of the service and tabulated in Excel spreadsheet. ®, being divided into positive and negative samples, and a descriptive analysis was performed with absolute and percentage values. Results: In general, the most commonly occurring bacteria were Acinetobacter baumannii (20.3%), Pseudomonas aeruginosa(19.7%), Klebsiella pneumoniae (15.1%), Staphylococcus aureus (11.9%), Staphylococcus negative coagulase (7.2%) and Escherichia coli (5.7%). The most resistant bacterial species were Acinetobacter baumanni, Klebisiella pneumoniae, Pseudomonas aeruginosa, Eschericia coli, Serratia marcencens andEnterobacter cloacae.Conclusion: The data from this study allow the knowledge of the bacterial profile found in hospitalized patients, which may guide the treatment of infections and consequently decrease the selection of multidrug resistant bacteria, helping in the prevention and control of nosocomial infections.

Antimicrobial resistance and plasmid replicons in Yersinia enterocolitica strains isolated in Brazil in 30 years

Abstract Some studies evaluated the resistance profile of the Y. enterocolitica strains isolated in diverse countries. However, in Brazil the isolation and the study of Y. enterocolitica are not common and therefore information about the antimicrobial resistance profile of this species in this country is scarce. Therefore, the aim of this study was to evaluate the antimicrobial resistance of Y. enterocolitica of biotypes 1A, 2 and 4 isolated from clinical and non-clinical sources between 1979 and 2012, in Brazil. This study showed that some Yersinia enterocolitica of different biotypes remain susceptible to antimicrobials used for gastroenteritis treatment. Moreover, neither acquired resistance genes nor diversity of plasmids replicons were found; however, variation in the in vitro intrinsic resistant pattern was detected, except the non-resistance to cefoxitin in all strains. Notwithstanding, due to epidemiological link between Y. enterocolitica and the pork production chain, monitoring plasmid acquired resistance in Y. enterocolitica could also be considered for antimicrobial resistance control purposes and food safety measures.

Antimicrobial resistance profile of the clinical isolates in Fuzhou First People's Hospital, Jiangxi during 2015 / 中国感染与化疗杂志

Objective To investigate the antimicrobial resistance profile of clinical isolates in Fuzhou First People's Hospital during 2015. Methods? The?bacterial?isolates?were?identified?using?ATB?Reader?semi-automatic?equipment?via?colorimetric?method.?The antimicrobial susceptibility was tested by disk diffusion method. The results were interpreted according to the CLSI breakpoints issued in 2015. All data were analyzed by WHONET 5.5 software. Results A total of 1215 non-duplicate clinical isolates were collected during 2015, including gram negative bacteria (70.6%) and gram positive bacteria (29.4%). The prevalence of MRSA was 50.0 % in S. aureus and the prevalence of MRCNS was 84.1 % in coagulase-negative Staphylococcus. Most MRSA strains (80.3?%)?were?resistant?to?erythromycin,?tetracycline?and?norfloxacin.?No?staphylococcal?isolate?was?found?resistant?to?vancomycin?or teicoplanin. The prevalence of ESBLs was 52.5% in E. coli and 34.7% in K. pneumoniae. Ten strains of Enterobacteriaceae were resistant to carbapenems. Less than10% of the P. aeruginosa isolates were resistant to amikacin, cefoperazone-sulbactam, meropenem and tobramycin. About 2.4% and 51.8% of the Acinetobacter isolates were resistant to polymyxin E and cefoperazone-sulbactam, respectively, while more than 75% of these strains were resistant to other commonly used antimicrobial agents. Conclusions Most of the clinical isolates are gram-negative bacilli in our hospital during 2015. Antimicrobial resistance remains an important clinical concern, which should be addressed seriously.

Análise molecular da expressão do fenótipo multi-droga resistente (MDR) em enterobactérias isoladas de amostras clínicas após exposição in vitro ao Imipenem / Molecular analysis of multi-drug resistant phenotype expression (MDR) in enterobacteria isolated from clinical specimens after exposure in vitro to imipenem

Após o surgimento e disseminação das ß-lactamases de amplo espectro em membros da família Enterobacteriaceae, os antibióticos carbapenêmicos (imipenem, meropenemeertapenem) têm sido considerados a terapia de escolha devido à estabilidade apresentada contra estas enzimas. A desvantagem destes antibióticos é a sua capacidade de induzir resistência aos ß-lactâmicos e a outros antibióticos quimicamente não relacionados. O imipenem tem favorecido a indução de cefalosporinases cromossômicas (AmpC) e também tem sido relacionado, in vivo, com a seleção de mecanismos intrínsecos de resistência, contribuindo com o perfil multi -droga resistente (MDR). Esse perfil é freqüentemente associado à diminuição da permeabilidade por alteração na síntese de porinas em conjunto com um aumento da atividade de bombas de efluxo, as quais não permitem o estabelecimento de uma concentração ativa do antibiótico no interior da célula bacteriana. O presente trabalho teve como objetivo avaliar o estabelecimento do perfil MDR em enterobactérias provenientes de isolados clínicos em função da exposição a diferentes concentrações de imipenemin vitro. A seleção do grupo das amostras estudadas foi feito por meio da determinação do perfil de sensibilidade dos isolados, tipagem molecular e ensaio de hidrólise de Imipenem. Nos isolados selecionados para a indução foi realizada numa etapa inicial (etapa basal) a análise de porinas de membrana externa por SDS-PAGE e o estudo de genes codificadores de ß-lactamases pela técnica de PCR. O estudo do estabelecimento do perfil MDR foi feito por meio de passagens sucessivas das amostras em meio contendo concentrações sub-inibitórias de imipenem seguido de análise fenotípica (CIM e acúmulo do antibiótico intracelular e SDS-PAGE), e a análise da expressão gênica de genes associados a permeabilidade de membrana (ompC, ompF eAcrA) e genes reguladores(marA e ompR). Após a indução com o imipenem, 77% dos isolados induzidos aumentaram a CIM para os carbapenêmicos, mudando assim o perfil de resistência observado na etapa basal Também foi afetado o perfil de resistência para outros antibióticos não relacionados a ß-lactámicos, porém numa percentagem menor. Com relação à alteração da permeabilidade, a perda de porina foi observada apenas para um isolado, no entanto a diminuição na expressão gênica de Omp36 foi significativa desde o começo da indução. A expressão da bomba de efluxoAcrAB foi afetada pela indução com imipenem, aumentando significativamente a expressão de AcrA, enquanto os reguladores estudados, MarA e OmpR tiveram a sua expressão induzida pelo imipenem. Foi possível observar também associação do nível de expressão gênica do regulador MarA com a expressão de AcrA,porém não foi possível observar uma associação estatisticamente significativa deste regulador com o perfil de expressão de OMPs. A indução de OmpR foi associado com um aumento da expressão de RNAm de Omp35, já para Omp36 foi possível observar apenas uma tendência na repressão deste gene. O estudo da resposta destes genes reguladores e determinantes de resistência, em resposta à exposição ao com o imipenem in vitro, permitiu reportar o comportamento molecular da bactéria numa resposta adaptativa no estagio inicial do estabelecimento do fenótipo MDR. A utilização de isolados clínicos com diversos determinantes de resistência permitiu observar a variabilidade nas respostas adaptativas das enterobacterias, o que é fundamental para a compreensão dos mecanismos de adaptação da bactéria e sua contribuição na falha terapêutica

After emergence and broad dissemination of extended spectrum ß-lactamases into the Enterobacteriaceae family, the carbapenemic antibiotics (imipenem, meropenem and ertapenem) have been considered the chosen therapy in the treatment of nosocomial infections by the stability that these antibiotics show to these enzymes. The disadvantage of carbapenems is theirs capacity to induce resistance against ß-lactamics and to other chemically unrelated antibiotics. The imipenem has been shown to induce chromosomal cephalosporinases (AmpC) and it was also related, in vivo, with the selection of intrinsic mechanism leading to multi-drug resistance profile (MDR). This profile is usually associated with membrane impermeability due to reduced outer membrane porin synthesis with an incremented activity of efflux pumps, which results in a reduced concentration of antibiotics inside the bacteria. This study aimed to evaluate the establishment of the MDR profile in Enterobacteriaceae from clinical isolates by exposure to different concentrations of imipenem in vitro. The selection of the study group was performed by determination of antibiotic susceptibility profile,molecular typing and hydrolysis assay of imipenem. In the selected isolates submitted to induction, in an initial step (baseline), was performed the outer membrane porin analysis by SDS-PAGE and the gene-specific amplification of B-lactamase enzymes by PCR. The study of the establishment of MDR was performed by progressive passages with subclinical concentrations of imipenem, followed each one by the evaluation of phenotypic profile (MIC, accumulation antibiotic in celland SDS-PAGE) and gene expression analysisof genes related to membrane permeability (ompC, ompF and acrA) and regulatory genes(MarA and ompR). After induction with imipenem, 77 % of the isolates increased the MIC for the carbapenems, changing the resistance profile at the baseline. In a lesser percentage, the resistance profile to other ß-lactams-unrelated antibiotics was also affected. Loss of porin was observed only for an isolated, however a significantly decreased Omp36 mRNA expression was observed from the start of induction. The expression of the efflux pump AcrAB ,was also affected by the imipenem induction, significantly increasing the AcrA gene expression, whereas the studied regulatory genes,MarA and OmpR,were induced by the imipenem. It was also possible to observe an association between the expression of the regulator MarA and the expression of AcrA, nevertheless no association was observed between this regulator and OMPs . OmpR induction was associated with an increased Omp35mRNA expression, however only a trend for the repression of Omp36was observed. The study of the response of these regulatory genes and genetic determinants of resistance, in response to the imipenem exposure in vitro, allowed to report the molecular behavior of the bacteria in an adaptive response in the initial stage of the establishment of a MDR phenotype. The use of clinical isolates with diverse resistance determinants allowed observing the variability in adaptive responses in enterobacteria, which is important to understand the adaptive mechanisms of bacteria to this antibiotic, the involvement in the emergence of the MDR profile and its contribution to the treatment failure

Characterization of Escherichia coli virulence genes, pathotypes and antibiotic resistance properties in diarrheic calves in Iran

BACKGROUND: Calf diarrhea is a major economic concern in bovine industry all around the world. This study was carried out in order to investigate distribution of virulence genes, pathotypes, serogroups and antibiotic resistance properties of Escherichia coli isolated from diarrheic calves. RESULTS: Totally, 76.45% of 824 diarrheic fecal samples collected from Isfahan, Chaharmahal, Fars and Khuzestan provinces, Iran were positive for E. coli and all of them were also positive for cnf2, hlyA, cdtIII, f17c, lt, st, stx1, eae, ehly, stx2 and cnf1 virulence genes. Chaharmahal had the highest prevalence of STEC (84.61%), while Isfahan had the lowest (71.95%). E. coli serogroups had the highest frequency in 1-7 days old calves and winter season. Distribution of ETEC, EHEC, AEEC and NTEC pathotypes among E. coli isolates were 28.41%, 5.07%, 29.52% and 3.49%, respectively. Statistical analyses were significant for presence of bacteria between various seasons and ages. All isolates had the high resistance to penicillin (100%), streptomycin (98.25%) and tetracycline (98.09%) antibiotics. The most commonly detected resistance genes were aadA1, sul1, aac[3]-IV, CITM, and dfrA1. The most prevalent serogroup among STEC was O26. CONCLUSIONS: Our findings should raise awareness about antibiotic resistance in diarrheic calves in Iran. Clinicians should exercise caution when prescribing antibiotics.

Distribution of serotypes and evaluation of antimicrobial susceptibility among human and bovine Streptococcus agalactiae strains isolated in Brazil between 1980 and 2006

Streptococcus agalactiae is a common agent of clinical and subclinical bovine mastitis and an important cause of human infections, mainly among pregnant women, neonates and nonpregnant adults with underlying diseases. The present study describes the genetic and phenotypic diversity among 392 S. agalactiae human and bovine strains isolated between 1980 and 2006 in Brazil. The most prevalent serotypes were Ia, II, III and V and all the strains were susceptible to penicillin, vancomycin and levofloxacin. Resistance to clindamycin, chloramphenicol, erythromycin, rifampicin and tetracycline was observed. Among the erythromycin resistant strains, mefA/E, ermA and, mainly, ermB gene were detected, and a shift of prevalence from the macrolide resistance phenotype to the macrolidelincosamide- streptogramin B resistance phenotype over the years was observed. The 23 macrolide-resistant strains showed 19 different pulsed-field gel electrophoresis profiles. Regarding macrolide resistance, a major concern in S. agalactiae epidemiology, the present study describes an increase in erythromycin resistance from the 80s to the 90s followed by a decrease in the 2000-2006 period. Also, the genetic heterogeneity described points out that erythromycin resistance in Brazil is rather due to horizontal gene transmission than to spreading of specific macrolide-resistant clones.

Trends in antimicrobial resistance among clinical isolates of enterococci in a Brazilian tertiary hospital: a 4-year study / Evolução da resistência aos antimicrobianos entre isolados clínicos de enterococos em um hospital terciário brasileiro: um estudo de 4 anos

INTRODUCTION: In the past two decades members of the genus Enterococcus have emerged as important nosocomial pathogens worldwide. This study prospectively analyzed the distribution of species and trends in antimicrobial resistance among clinical isolates of enterococci in a Brazilian tertiary hospital from 2006-2009. METHODS: Enterococcal species were identified by conventional biochemical tests. The antimicrobial susceptibility profile was performed by disk diffusion in accordance with the Clinical and Laboratory Standards Institute (CLSI). A screening test for vancomycin was also performed. Minimal inhibitory concentration (MIC) for vancomycin was determined using the broth dilution method. Molecular assays were used to confirm speciation and genotype of vancomycin-resistant enterococci (VRE). RESULTS: A total of 324 non-repetitive enterococcal isolates were recovered, of which 87 percent were E. faecalis and 10.8 percent E. faecium. The incidence of E. faecium per 1,000 admissions increased significantly (p < 0.001) from 0.3 in 2006 to 2.3 in 2009. The VRE rate also increased over time from 2.5 percent to 15.5 percent (p < 0.001). All VRE expressed high-level resistance to vancomycin (MIC >256µg/ mL) and harbored vanA genes. The majority (89.5 percent) of VRE belonged to E. faecium species, which were characteristically resistant to ampicillin and quinolones. Overall, ampicillin resistance rate increased significantly from 2.5 percent to 21.4 percent from 2006-2009. Resistance rates for gentamicin, chloramphenicol, tetracycline, and erythromycin significantly decreased over time, although they remained high. Quinolones resistance rates were high and did not change significantly over time. CONCLUSIONS: The data obtained show a significant increasing trend in the incidence of E. faecium resistant to ampicillin and vancomycin.

INTRODUÇÃO: Nas últimas duas décadas, os enterococos emergiram como importantes patógenos nosocomiais no mundo inteiro. Neste estudo, foi analisada a distribuição das espécies e a evolução da resistência aos antimicrobianos entre isolados clínicos de enterococos obtidos em um hospital terciário, no período de 2006 a 2009. MÉTODOS: As espécies foram identificadas por testes bioquímicos convencionais e o perfil de sensibilidade foi determinado pelo método de disco difusão. A sensibilidade à vancomicina foi também determinada pela triagem em agar e pela concentração inibitória mínima (CIM). Testes moleculares foram utilizados para confirmar as espécies e determinar os genótipos dos enterococos resistentes à vancomicina (VRE). RESULTADOS: Foram analisadas 324 amostras de enterococos, sendo 87 por cento E. faecalis e 10,8 por cento E. faecium. A incidência de E. faecium por 1.000 pacientes internados aumentou significativamente (p < 0,001) de 0,3 em 2006 para 2,3 em 2009. A taxa de VRE também aumentou significativamente de 2,5 por cento para 15,5 por cento (p < 0,001). Todos os VRE apresentaram genótipo VanA e CIM >256µg/mL para vancomicina. A maioria (89,5 por cento) dos VRE pertencia à espécie E. faecium e foram resistentes à ampicilina e quinolonas. Foi observado um aumento significativo na taxa de resistência à ampicilina, de 2,5 por cento (2006) para 21,4 por cento (2009). As taxas de resistência para gentamicina, cloranfenicol, tetraciclina e eritromicina diminuíram significativamente no período do estudo. Para as quinolonas, as taxas de resistência foram elevadas não alteraram significativamente, no período do estudo. CONCLUSÕES: Os resultados do presente estudo mostram um aumento significativo na incidência de E. faecium resistentes à ampicilina e vancomicina.

Perfil de resistência antimicrobiana de Escherichia coli isoladas do açude Santo Anastácio, Ceará, Brasil / Resistance profile of Escherichia coli isolated from the environment

Este trabalho objetivou caracterizar a resistência antimicrobiana de 43 cepas de Escherichia coli isoladas do açude Santo Anastácio (Fortaleza, CE), durante os meses de janeiro a abril de 2007. As cepas foram submetidas a testes de suscetibilidade a oito antimicrobianos, tendo 67,4% delas apresentado sensibilidade a todos. Observou-se resistência à tetraciclina (25,6%), ao sulfazotrin (18,6%), ao ácido nalidixíco (9,3%) e a ciprofloxacina (4,7%). Nenhuma resistência foi observada aos betalactâmicos. Nove (21%) cepas apresentaram multirresistência, com um percentual de 78% para resistência cromossômica e 56% para resistência plasmidial. A presença de bactérias resistentes pode estar relacionada ao lançamento de antimicrobianos nas águas através de esgotos, sendo que o uso inadequado dessas águas pode comprometer a saúde da população.

The aim of this study was to determine the antimicrobial resistance of 43 Escherichia coli strains isolated from the Santo Antonio weir (Fortaleza, CE, Brazil) from January to April 2007. Susceptibility tests performed with 8 antimicrobials indicated that 67.5% of the strains were susceptible to all of them. Resistance to tetracycline (25.6%), sulfazotrim (18.6%), nalidixic acid (9.3%), and ciprofloxacin (4.7%) was observed. The strains did not show resistance to betalactamics. Nine strains (21%) were multiresistant, the resistance being chromosome (78%) and plasmid (56%) mediated. The presence of resistant bacteria may be related to antimicrobials in the sewage discharged into the weir, and the inappropriate use of this body of water may pose human health risks.

Perfil plasmídico y resistencia antimicrobiana en cepas de Shigella aisladas en Cuba / Plasmidic profile and antimicrobial resistance in Shigella strains isolated in Cuba

Se investigó un total de 240 cepas de Shigella, procedentes de los Centros Provinciales de Higiene y Epidemiología, durante el período de enero a diciembre de 2002. Estas especies constituyen los microorganismos aislados con mayor frecuencia de infecciones diarreicas agudas en los países en vías de desarrollo y en Cuba. Mediante el estudio de diferentes marcadores fenotípicos y genotípicos como: serotipaje, estudios de resistencia a drogas antimicrobianas y perfil plasmídico, se investigó la relación epidemiológica de las cepas en estudio. Los serogrupos predominantes fueron: S. flexneri 142 (59 %) y S. sonnei 76 cepas (32 %). El comportamiento de la susceptibilidad antimicrobiana mostró 79,2 % de cepas resistentes. Al analizar el comportamiento de S. flexneri según la región de origen, el perfil de resistencia y el perfil plasmídico se realizaron 2 agrupamientos y en el serogrupo S. sonnei se encontraron 5 agrupamientos. Los resultados obtenidos demuestran la heterogeneidad genética en las cepas de Shigella que circulan en el país.

240 Shigella strains from the Provincial Centers of Hygine and Epidemiology were investigated from Janaury to December, 2002. These species are the isolated microorganisms with the highest frequency of acute diarrheal infections in the developing countries and in Cuba. By the study of different phenotypic and genotypic markers as serotyping, studies of resistance to antimicrobial drugs and plasmidic profile, the epidemiological relation of the strains under study was analyzed. The predominating serogroups were: 142 S. flexneri (59 %) and 76 S. sonnei strains (32 %). The antimicrobial susceptibility behavior showed 79.2 % of resistant strains. The resistance phenotypes most frequently found were: streptomycin, trimethropim-sulfamethoxazole: 71 (37.4 %); ampicillin, ampicillin-sulbactam, tetracycline, trimethroprim-sulfametoxazole, cloramphenicol: 24 (12.7 %); ampicillin, ampicillin-sulbactram, streptomycin, tetracycline, amoxicyllin- clavulanic acid, trimethropim-sulfametoxazole: 18 (9.5%). The plasmidic profiles detected in the S. flexneri serogrup were 6. Each profile contained between 2 and 7 plasmides and they were excluding. The diversity index was (ID 0.85), whereas in the S. sonnei serogroup there were 8 different profiles. Each one had between 2 and 8 plasmides with ID (0.86). On analyzing the behavior of S. flexneri according to the region of origen, the resistance profile and the plasmidic profile, 2 groupings were created.and 5 groupings were found in the S. sonnei serogroup. The results obtained showed the genetic heterogeneity in the Shigella strains that circulate in the country.