High antimicrobial resistance in Salmonella spp. and Escherichia coli isolates from swine fecal samples submitted to a veterinary diagnostic laboratory in Colombia

Background: Commensal microflora such as Escherichia coli and Enterococcus spp. are representative indicators of antimicrobial resistance (AMR) as they are part of the normal intestinal microflora and can acquire and disseminate AMR to pathogenic or zoonotic bacteria like Salmonella spp. Objective: To investigate the state of AMR among E. coli and Salmonella spp., potential pathogens in humans, isolated from cecal contents of pigs submitted to a veterinary diagnostic laboratory in Colombia from 2016 to 2019. Methods: Susceptibility testing was conducted using the Kirby-Bauer disk diffusion method according to the Clinical and Laboratory Standards Institute guidelines for antimicrobial zone diameter breakpoints. An E. coli strain (ATCC 25922) was used as the quality control organism. Isolates showing resistance to three or more antimicrobial classes were classified as multidrug-resistant (MDR) as defined by a joint group of the European Centre for Disease prevention and Control and the Center for Disease Control and Prevention of the USA. Results: A total of 112 E. coli and 192 Salmonella spp. colonies were isolated from 557 samples received between 2016 and 2019. In order of decreasing frequency, E. coli was resistant to tetracycline (100%), sulfamethoxazol-trimethoprim (97.5%), amoxicillin (86.4%), enrofloxacin (82.6%), tylosin (82.1%), doxycycline (59%), neomycin (50%), ciprofloxacin (45.5%), ceftiofur (35%), gentamicin (30%), tilmicosin (29%), and fosfomycin (12.5%). When compared with E. coli, Salmonella spp. was generally resistant to the same agents with slightly less resistance (between 10-30%) to eight of the antimicrobials tested. Salmonella spp. showed <20% resistance to three antimicrobials, as follows: neomycin (17%), gentamicin (16%), and fosfomycin (14%). Multi-resistance occurred in 68.7% (77/112) of E. coli and 70.3% (135/192) of Salmonella spp. isolates. Resistance of Salmonella spp. was alarming to all the critically important antimicrobials tested: fluoroquinolones (enrofloxacin, ciprofloxacin), ceftiofur (third- generation cephalosporin), and macrolides (tylosin). Conclusions: According to our results, there is a high level of multi- drug resistance (MDR) in E. coli and Salmonella spp. It is necessary to implement a nationwide antimicrobial resistance monitoring program in Colombia, together with proper antimicrobial prescribing guidelines for pigs. The indiscriminate use of antimicrobial growth promoters by the swine industry is generating widespread bacterial resistance and should be discontinued.

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Antecedentes: Flora comensal como espécies de Escherichia coli e Enterococcus são tipicamente escolhidas como indicadores representativos de la resistência antimicrobiana (AMR), pois fazem parte da flora intestinal normal e podem adquirir e disseminar AMR a bactérias patogênicas ou zoonóticas como Salmonella spp. Objetivo: Investigar o estado da AMR entre E. coli e Salmonella spp. isolados do conteúdo cecal de porcos colombianos submetidos ao Laboratório de Diagnóstico Veterinário de 2016 a 2019, ambos sendo patógenos potenciais em humanos. Métodos: O teste de suscetibilidade foi conduzido usando o método de difusão em disco Kirby-Bauer de acordo com as diretrizes do Instituto de Padrões Clínicos e Laboratoriais para pontos de quebra de diâmetro da zona antimicrobiana. A cepa de E. coli (ATCC 25922) foi usada como organismo de controle de qualidade. Os isolados que apresentam resistência a três ou mais classes de antimicrobianos foram classificados como multirresistentes (MDR), conforme definido por um grupo conjunto do Centro Europeu para Prevenção e Controle de Doenças e Centro para Controle e Prevenção de Doenças dos EUA. Resultados: Um total de 112 E. coli e 192 Salmonella spp. foram isolados de 557 amostras submetidas entre 2016 e 2019. Em ordem decrescente de frequência, a resistência a E. coli foi: tetraciclina (100%), sulfametoxazol-trimetoprim (97,5%), amoxicilina (86,4%), enrofloxacina (82,6%), tilosina (82,1%), doxiciclina (59%), neomicina (50%), ciprofloxacina (45,5%), ceftiofur (35%), gentamicina (30%), tilmicosina (29%) e fosfomicina (12,5%). Quando comparada com E. coli, Salmonella spp. foi geralmente resistente aos mesmos agentes com resistência ligeiramente menor (entre 10-30%) a oito dos antimicrobianos. Apenas três antimicrobianos apresentaram resistência a Salmonella spp. abaixo de 20% da seguinte forma: neomicina (17%), gentamicina (16%) e fosfomicina (14%). Multi-resistência ocorreu em 68,7% (77/112) de E. coli e 70,3% (135/192) de Salmonella spp. isolados. Resistência de Salmonella spp. foi alarmante para todos os antimicrobianos criticamente importantes testados: fluoroquinolonas (enrofloxacina, ciprofloxacina), ceftiofur (cefalosporina de terceira geração) e macrolídeos (tilosina). Conclusões: Esses resultados indicam um alto nível de resistência a múltiplos medicamentos (MDR) e que um Programa Nacional de Monitoramento da Resistência Antimicrobiana é necessário para a Colômbia, juntamente com a implementação de diretrizes de prescrição de antimicrobianos para suínos. O uso indiscriminado de antimicrobianos para promoção de crescimento na indústria suína está claramente promovendo resistência generalizada e deve ser interrompido.

Infección nosocomial en Cuidados Intensivos del Hospital Universitario Clínico Quirúrgico Comandante Faustino Pérez Hernández, de Matanzas / Nosocomial infection in the Intensive Care Unit of the Teaching Clinic-Surgical Hospital Faustino Pérez Hernández, of Matanzas

RESUMEN Introducción: la diseminación de microorganismos multirresistentes en el hospital, constituye un importante problema epidemiológico y terapéutico que afecta especialmente a pacientes de la Unidad de Cuidados Intensivos. Objetivo: escribir el comportamiento de las infecciones nosocomiales y la resistencia antimicrobiana en la Unidad de Cuidados Intensivos. Materiales y métodos: se realizó un estudio de tipo descriptivo, observacional y prospectivo en la Unidad de Cuidados Intensivos del Hospital Universitario Clínico Quirúrgico Comandante Faustino Pérez Hernández, durante el primer semestre de 2020. El universo estuvo constituido por 102 pacientes que ingresaron en la Unidad de Cuidados Intensivos en el período estudiado, a los que se les realizó estudios microbiológicos. Las variables analizas fueron: causas de ingreso, edad, infecciones nosocomiales, neumonía en ventilados, gérmenes, resistencia antimicrobiana y mortalidad. Se expresaron en tablas y gráficos porcentuales. Resultados: el sexo masculino presentó mayor número de infección nosocomial respecto al femenino, en edades diferentes de la vida. La causa más frecuente de ingreso fue el politrauma. El sitio más común de infección nosocomial fue la vía respiratoria. Predominaron gérmenes como los bacilos gramnegativos fermentadores y las enterobacterias. Antibióticos como los inhibidores de las betalactamasas, otras penicilinas, quinolonas, cefalosporinas, aminoglucósidos y meropenen han adquirido un mayor porciento de resistencia. Conclusiones: la infección nosocomial por bacterias multirresistentes a los antibióticos estratégicos, es un problema dentro de la Unidad de Cuidados Intensivos asociado a la ventilación mecánica, que provoca una elevada mortalidad (AU).

ABSTRACT Introduction: the spread of multi-resistant microorganisms in the hospital is a major epidemiological and therapeutic problem that particularly affects critical patients admitted to the Intensive Care Unit. Objective: to describe the behavior of nosocomial infections and antimicrobial resistance in the Intensive Care Unit. Materials and Methods: a descriptive, observational and prospective study was carried out in the Intensive Care Unit of the Teaching Clinic-Surgical Hospital Faustino Pérez Hernández, during the first half of 2020. The universe was formed by 102 patients who entered the Intensive Care Unit during the studied period, to whom microbiological studies were carried out. The analyzed variables were the following: causes of admission, age, nosocomial infections, ventilator-associated pneumonia, germs, antimicrobial resistance and mortality. The results were expressed in tables and percentage charts. Results: Male sex showed the highest number of nosocomial infection compared to the female, at different ages of life. The most common cause of admission was polytrauma. The most common site of nosocomial infection was the airway. Germs like fermentative Gram-negative bacilli and enterobacteria predominated. Antibiotics such as beta-lactamase inhibitors, other kinds of penicillin, quinolones, cephalosporin, aminoglycosides and meropenen have acquired a higher percent of resistance. Conclusions: nosocomial infection caused by bacteria that have developed multi-resistance to strategic antibiotics is a problem within the Intensive Care Unit, associated to mechanical ventilation, and leads to high mortality (AU).

Biochemical identification techniques and antibiotic susceptibility profile of lipolytic ambiental bacteria from effluents / Técnicas de identificação bioquímica e perfil de suscetibilidade antibiótica de bactérias ambientais lipolíticas de efluentes

Abstract Different methodologies have been developed throughout the years to identify environmental microorganisms to improve bioremediation techniques, determine susceptibility profiles of bacteria in contaminated environments, and reduce the impact of microorganisms in ecosystems. Two methods of bacterial biochemical identification are compared and the susceptibility profile of bacteria, isolated from residential and industrial wastewater, is determined. Twenty-four bacteria were retrieved from the bacteria bank of the Environmental Microbiology Laboratory at the Institute of Biology (IB) of the Universidade Federal de Pelotas, Pelotas, Brazil. Bacteria were identified by conventional biochemical tests and by the VITEK ®2 automated system. Further, the susceptibility profile to antibiotics was also determined by the automated system. Six species of bacteria (Raoutella planticola, K. pneumoniae ssp. pneumoniae , Serratia marcescens, Raoutella sp., E. cloacae and Klebsiella oxytoca) were identified by conventional biochemical tests, while three species of bacteria (K. pneumoniae ssp. pneumoniae, S. marcescens and K. oxytoca ) were identified by VITEK®2 automated system. VITEK ®2 indicated agreement in 19 (79.17%) isolates and difference in five (20.83%) isolates when compared to results from conventional biochemical tests. Further, antibiotic susceptibility profile results showed that all isolates (100%) were resistant to at least one out of the 18 antibiotics tested by VITEK®2. Thus, no multi-resistant bacteria that may be used in effluent treatment systems or in bioremediation processes have been reported. Results indicate VITEK ® 2 automated system as a potential methodology in the determination of susceptibility profile and identification of environmental bacteria.

Resumo Diferentes metodologias foram desenvolvidas ao longo dos anos para identificar microrganismos ambientais para melhorar as técnicas de biorremediação, determinar perfis de suscetibilidade de bactérias em ambientes contaminados e reduzir o impacto de microrganismos nos ecossistemas. Dois métodos de identificação bioquímica bacteriana são comparados e o perfil de susceptibilidade de bactérias, isoladas de efluentes residenciais e industriais, é determinado. Vinte e quatro bactérias foram coletadas do banco de bactérias do Laboratório de Microbiologia Ambiental do Instituto de Biologia (IB) da Universidade Federal de Pelotas, Pelotas, Brasil. As bactérias foram identificadas por testes bioquímicos convencionais e pelo sistema automatizado VITEK®2. Além disso, o perfil de suscetibilidade aos antibióticos também foi determinado pelo sistema automatizado. Seis espécies de bactérias (Raoutella planticola , K. pneumoniae ssp. pneumoniae, Serratia marcescens, Raoutella sp., E. cloacae e Klebsiella oxytoca) foram identificadas por testes bioquímicos convencionais, enquanto três espécies de bactérias (K. pneumoniae ssp. pneumoniae, S. marcescens e K. oxytoca) foram identificados pelo sistema automatizado VITEK®2. VITEK®2 indicou concordância em 19 (79,17%) isolados e diferença em cinco (20,83%) isolados quando comparados aos resultados de testes bioquímicos convencionais. Além disso, os resultados do perfil de suscetibilidade aos antibióticos mostraram que todos os isolados (100%) foram resistentes a pelo menos um dos 18 antibióticos testados pelo VITEK®2. Assim, não foram relatadas bactérias multirresistentes que possam ser usadas em sistemas de tratamento de efluentes ou em processos de biorremediação. Os resultados indicam que o sistema automatizado VITEK ® 2 é uma metodologia potencial na determinação do perfil de suscetibilidade e identificação de bactérias ambientais.

Evaluation of Intervention Effect of Multi-department Participating in Prevention and Control of Multi-resistant Bacteria Infection in Our Hospital / 中国药房

OBJECTIVE:To provide reference for further promoting rational use of antibiotics in hospitals and curbing bacterial drug resistance. METHODS:Retrospective investigation and comparative analysis were made on the clinical application of antibiotics,the inspection of microbial specimens before use of antibiotics,the detection of multidrug-resistant bacteria,the occurrence of nosocomial infection before and after multi-sectoral participation in the prevention and control of multi-resistant bacteria infection in our hospital(from Jul. 2015 to Jun. 2016 as before intervention and from Oct. 2016 to Sept. 2017 as after intervention) in order to evaluate the intervention effect of this work. RESULTS:After intervention,the utilization rate of antibiotics,antibiotics use intensity and rate of combined use decreased from 64.15%,48.86 DDDs/hundred person per day, 35.87% to 57.67%,36.58 DDDs/hundred person per day,11.47%,respectively (P＜0.05). Both the de-escalation use rate of special grade antibiotics and the rate of antibiotics choice based on the drug sensitivity test increased from 12.45% and 48.28% to 56.63% and 77.89%(P＜0.001). Microbiological specimen inspection rate, total specimen inspection rate before using non-restricted use,restricted use and special use antibiotics and the sterile specimen inspection rate before using antibiotics increased from 23.58%,43.15%,71.76%,36.37% and 20.82% to 40.61%,58.43%,95.77%,51.33% and 38.27%, respectively(P＜0.05 or P＜0.01). The detection rate of MRSA,CRE and MDR-PA decreased from 4.43%,2.80%,1.99% to 1.36%,1.26%,0.80%,respectively (P＜0.05 or P＜0.01),and the detection rates of multi-resistant bacteria decreased from 16.21% to 10.68%(P＜0.05). Meanwhile,the incidence of nosocomial infection decreased from 1.41% to 1.08%(P＜0.05),and there was no outbreak of nosocomial infection. CONCLUSIONS:The intervention effect of multi-department participation in prevention and control of multi-resistant bacterial infection is significant,which helps to promote rational use of antibiotics and curb bacterial drug resistance,and it is necessary to continue to operate as a long-term management mechanism.

Biochemical identification techniques and antibiotic susceptibility profile of lipolytic ambiental bacteria from effluents

Abstract Different methodologies have been developed throughout the years to identify environmental microorganisms to improve bioremediation techniques, determine susceptibility profiles of bacteria in contaminated environments, and reduce the impact of microorganisms in ecosystems. Two methods of bacterial biochemical identification are compared and the susceptibility profile of bacteria, isolated from residential and industrial wastewater, is determined. Twenty-four bacteria were retrieved from the bacteria bank of the Environmental Microbiology Laboratory at the Institute of Biology (IB) of the Universidade Federal de Pelotas, Pelotas, Brazil. Bacteria were identified by conventional biochemical tests and by the VITEK ®2 automated system. Further, the susceptibility profile to antibiotics was also determined by the automated system. Six species of bacteria (Raoutella planticola, K. pneumoniae ssp. pneumoniae , Serratia marcescens, Raoutella sp., E. cloacae and Klebsiella oxytoca) were identified by conventional biochemical tests, while three species of bacteria (K. pneumoniae ssp. pneumoniae, S. marcescens and K. oxytoca ) were identified by VITEK®2 automated system. VITEK ®2 indicated agreement in 19 (79.17%) isolates and difference in five (20.83%) isolates when compared to results from conventional biochemical tests. Further, antibiotic susceptibility profile results showed that all isolates (100%) were resistant to at least one out of the 18 antibiotics tested by VITEK®2. Thus, no multi-resistant bacteria that may be used in effluent treatment systems or in bioremediation processes have been reported. Results indicate VITEK ® 2 automated system as a potential methodology in the determination of susceptibility profile and identification of environmental bacteria.

Resumo Diferentes metodologias foram desenvolvidas ao longo dos anos para identificar microrganismos ambientais para melhorar as técnicas de biorremediação, determinar perfis de suscetibilidade de bactérias em ambientes contaminados e reduzir o impacto de microrganismos nos ecossistemas. Dois métodos de identificação bioquímica bacteriana são comparados e o perfil de susceptibilidade de bactérias, isoladas de efluentes residenciais e industriais, é determinado. Vinte e quatro bactérias foram coletadas do banco de bactérias do Laboratório de Microbiologia Ambiental do Instituto de Biologia (IB) da Universidade Federal de Pelotas, Pelotas, Brasil. As bactérias foram identificadas por testes bioquímicos convencionais e pelo sistema automatizado VITEK®2. Além disso, o perfil de suscetibilidade aos antibióticos também foi determinado pelo sistema automatizado. Seis espécies de bactérias (Raoutella planticola , K. pneumoniae ssp. pneumoniae, Serratia marcescens, Raoutella sp., E. cloacae e Klebsiella oxytoca) foram identificadas por testes bioquímicos convencionais, enquanto três espécies de bactérias (K. pneumoniae ssp. pneumoniae, S. marcescens e K. oxytoca) foram identificados pelo sistema automatizado VITEK®2. VITEK®2 indicou concordância em 19 (79,17%) isolados e diferença em cinco (20,83%) isolados quando comparados aos resultados de testes bioquímicos convencionais. Além disso, os resultados do perfil de suscetibilidade aos antibióticos mostraram que todos os isolados (100%) foram resistentes a pelo menos um dos 18 antibióticos testados pelo VITEK®2. Assim, não foram relatadas bactérias multirresistentes que possam ser usadas em sistemas de tratamento de efluentes ou em processos de biorremediação. Os resultados indicam que o sistema automatizado VITEK ® 2 é uma metodologia potencial na determinação do perfil de suscetibilidade e identificação de bactérias ambientais.

Control of multi-resistant bacteria and ventilator-associated pneumonia: is it possible with changes in antibiotics?

Potent antimicrobial agents have been developed as a response to the development of antibiotic-resistant bacteria, which especially affect patients with prolonged hospitalization in Intensive Care Units (ICU) and who had been previously treated with antimicrobials, especially third-generation cephalosporins.This study was to determine how changes in the empirical treatment of infections in ICU patients affect the incidence of Gram-negative bacteria species and their susceptibility to antimicrobials, and examine the impact of these changes on nosocomial infections. A prospective interventional study was performed in a university hospital during two periods: 1) First period (September 1999 to February 2000); and 2) Second period (August 2000 to December 2000); empirical treatment was changed from ceftriaxone and/or ceftazidime in the first period to piperacillin/tazobactam in the second. ICU epidemiological and infection control rates, as well as bacterial isolates from upper airways were analyzed. Ceftazidime consumption dropped from 34.83 to 0.85 DDD/1000 patients per day (p=0.004). Piperacillin/tazobactam was originally not available; its consumption reached 157.07 DDD/1000 patients per day in the second period (p=0.0002). Eighty-seven patients and 66 patients were evaluated for upper airway colonization in the first and second periods, respectively. There was a significant decrease in the incidence of K. pneumoniae (p=0.004) and P. mirabilis (p=0.036), restoration of K. pneumoniae susceptibility to cephalosporins (p<0.0001) and reduction of ventilator-associated pneumonia rates (p<0.0001). However, there was an increase in P. aeruginosa incidence (p=0.005) and increases in ceftazidime (p=0.003) and meropenem (p<0.0001) susceptibilities. Changing antimicrobial selective pressure on multi-resistant Gram-negative bacteria helps control ventilator-associated pneumonia and decreases antimicrobial resistance.