Extended-spectrum and AmpC ß-lactamases screening and antibiotic resistance profile of Escherichia coli isolated from urine / Análisis de las ß-lactamasas de espectro extendido y tipo AmpC y el perfil de resistencia a antibióticos de Escherichia coli aisladas de orina

Introduction: Antimicrobial resistance is a global concern since infections by resistant pathogens are associated with higher mortality and morbidity. Objective: To assess the prevalence of Escherichia coli isolates producing extended-spectrum and AmpC beta-lactamase (ESBL) in urine samples from patients at the Hospital Metropolitano de Santiago in Dominican Republic. Methods: Pathogen identification and antibiogram were carried out by the automated systems BD Phoenix or Microscan®. General information and past medical history were gathered from patients with a positive urine culture for E. coli. Manual ESBL/AmpC screening was performed with the commercial ESBL+AmpC screen disc kit from Liofilchem Laboratory, Italy. Results: One or both of the studied phenotypes were present in 36% of the analyzed isolates. Among the risk factors for the detection of E. coli producing ESBL and/or AmpC in urine were male gender, advanced age, placement of urinary catheter, arterial hypertension, neoplasms, and coexistence of two or more comorbidities. Apart from cephalosporins resistance, isolates producing ESBL and/or AmpC also showed higher resistance to other antibiotics, such as gentamicin (66.7%), ciprofloxacin and levofloxacin (83.3%), and ampicillin (91.7%). Furthermore, 85% of the ESBL/AmpC producing samples were multidrug resistant (resistant to 1 or more drugs in at least 3 different antibiotic categories). Conclusions: The high prevalence of antimicrobial resistance found in this study highlights the importance of implementing national and global measures to tackle the problem, especially in developing countries such as the Dominican Republic, where resources are scarce.

Introducción: La resistencia antimicrobiana es un grave problema global, pues las infecciones causadas por patógenos resistentes están asociadas con una mayor mortalidad y morbilidad. Objetivos: Analizar la prevalencia de aislados de Escherichia coli productores de β-lactamasas de espectro extendido (BLEE) y tipo AmpC procedentes de muestras de orina de pacientes del Hospital Metropolitano de Santiago en la República Dominicana. Métodos: La identificación del patógeno y el antibiograma fueron llevados a cabo mediante los sistemas automáticos BD Phoenix o Microscan®. Se recolectó información general y la historia médica de pacientes con un cultivo de orina positivo para E. coli. La detección de BLEE/AmpC se realizó de manera manual con el estuche comercial ESBL+AmpC de Liofilchem Laboratory, de Italia. Resultados: Un 36 % de las muestras analizadas mostraron uno o ambos fenotipos estudiados. Como factores de riesgo para la detección en orina de E. coli productoras de BLEE o AmpC se encontraron: sexo masculino, edad avanzada, colocación de un catéter urinario, hipertensión, neoplasmas y coexistencia de comorbilidades. Además de resistencia a las cefalosporinas, los aislados productores de BLEE y AmpC revelaron también elevada resistencia a otros antibióticos como gentamicina (66,7 %), ciprofloxacina y levofloxacina (83,3 %), y ampicilina (91,7 %). Un 85,0 % de las muestras productoras de BLEE/AmpC fueron multidrogorresistentes. Conclusiones: La elevada prevalencia de resistencia antimicrobiana encontrada en este estudio refleja la importancia de tomar medidas nacionales y globales para contener el problema, especialmente en países en desarrollo como República Dominicana, donde los recursos son escasos.

Restricción programada de cefalosporinas de tercera generación en contexto de un brote de bacilos gramnegativos productores de beta-lactamasas tipo AmpC en unidades críticas: una experiencia de la vida real / Third-generation cephalosporins programmed restriction in the context of an outbreak of AmpC beta-lactamase-producing gram-negative bacilli in critical units: a real-life experience

INTRODUCCIÓN: La restricción programada (RP) de antimicrobianos puede disminuir selectivamente la tasa de infecciones por determinados microorganismos. En este sentido, los bacilos gramnegativos productores de beta-lactamasas AmpC (BGN-blaAmpC) son seleccionados por el sobreuso de cefalosporinas de tercera generación (C3G). Estas bacterias, también adquieren genes y co-producen otras beta-lactamasas, como las de Nueva Delhi (BGN-blaNDM). OBJETIVOS: Disminuir la tasa de aislamiento de BGN-blaAmpC y BGN-blaNDM en cultivos de pacientes de la UCI luego de una RP de C3G en el marco de un brote nosocomial por estos microrganismos. MATERIALES Y MÉTODOS: Estudio cuasi-experimental, previo (P1= 12 meses) y posterior (P2= 12 meses) a una RP de C3G en un hospital de adultos, donde, en el contexto de brote mencionado, se aplicaron medidas de control de infecciones generales. El uso de antimicrobianos se expresó como "porcentaje de los días de tratamiento (%DDT)"/100 camas ocupadas al día (100-COD). Se compararon las tasas de aislamiento de BGN-blaAmpC y BGN-blaNDM en hemocultivos (HC), mini-lavados bronquio-alveolares (mB) y urocultivos (UC) en la UCI. RESULTADOS: En P2 el consumo de C3G fue 2,5% DDT/100-COD. Hubo un descenso en los aislamientos de BGN-blaAmpC en HC (RR 0,48 [0,2-0,9] p < 0,02) y mB (RR 0,52 [0,3-0,9] p < 0,02), así como también de BGN-blaNDM en HC (RR 8,1 [1,6-39,4] p < 0,00). Conclusiones: La RP de C3G se asoció con la reducción de los BGN-blaAmpC y BGN-blaNDM en HC, así como de los BGN-blaAmpC mB.

BACKGROUND: Programmed restriction (PR) of antimicrobials can selectively decrease the rate of infections by certain microorganisms. In this sense, AmpC beta-lactamase-producing gram-negative bacilli (GNB-blaAmpC) are selected for the overuse of third generation cephalosporins (3GC). These bacteria also acquire genes and co-produce other β-lactamases, such as New Delhi ones (GNB-blaNDM). AIM: To decrease the isolation rate of GNB- blaAmpC and GNB- blaNDM in cultures from ICU patients after a PR of 3GC. METHODS: Quasi-experimental study, before (P1= 12 months) and after (P2= 12 months) a PR of 3GC in an adults' hospital. The use of antibiotics was expressed as "percentage days of treatment (%DOT)" /100 beds occupied per day (100-BOD). The rates of GNB-blaAmpC and GNB-blaNDM were compared in blood cultures (BC), mini-bronchio alveolar lavages (mB) and urine cultures (UC) in the ICU. RESULTS: In P2, 3GC consumption was 2.5% DOT/100-COD. There was a decrease in GNB-blaAmpC from BC (RR 0.48 [0.2-0.9] p < 0.02) and mB (RR 0.52 [0.3-0.9] p < 0.02), as well as of GNB-blaNDM from BC (RR 8.1 [1.6-39.4] p < 0.00). Conclusions: PR of 3GC was linked to the reduction of GNB-blaAmpC and GNB-blaNDM in BC, as well as GNB-blaAmpC in mB from ICU patients.

ß-l; -lactamasas AmpC en bacilos gramnegativos de aislados clínicos en un centro hospitalario de tercer nivel en Colombia / AmpCß-l;-lactamases in Gram-negative bacilli from clinical isolates in a Colombian tertiary hospital

Introdución: Las ß-lactamasas AmpC son enzimas con capacidad hidrolítica, pueden ser de tipo constitutivo o inducible. No existe un método estandarizado para su determinación fenotípica por normas internacionales; la detección de estas mediante el uso de la biología molecular podría ser una alternativa útil para vigilancia y control de la diseminación de clones circulantes en el entorno hospitalario. Objetivo: Determinar el fenotipo de resistencia y genes expresados en la producción de ß-lactamasas AmpC en bacilos gramnegativos de aislados clínicos en un centro hospitalario. Métodos: Estudio observacional, descriptivo y de corte transversal. Se seleccionaron 78 cepas bacterianas como portadoras de ß- lactamasas AmpC. Se les realizó prueba de aproximación de disco; a las cepas con resultado positivo se seleccionaron para extracción de ADN y PCR multiplex para detección de 6 familias genes AmpC. Se determinó la frecuencia por tipo de muestra, servicio y comparación con el perfil de susceptibilidad. Resultados: De las cepas seleccionadas con fenotipo AmpC, el 57,6 por ciento (45/78) se consideró caso confirmado ß-lactamasas AmpC por su positividad para la prueba confirmatoria. La técnica molecular utilizada confirmó en el 40 por ciento (18/45) la presencia de genes AmpC. Se obtuvo con mayor frecuencia el gen MIR n= 9 (20 por ciento), seguido de DHA n= 7 (15 por ciento). Conclusiones: La detección oportuna de genes que codifican para ß-lactamasas AmpC permite establecer estrategias para evitar la circulación mediada por plásmidos en hospitales, así como utilizar mejores opciones terapéuticas que no induzcan a otros mecanismos de resistencia(AU)

Introduction: AmpC ß--lactamases are enzymes with hydrolytic activity. They may be either constitutive or inducible. No standardized method is available for their phenotypical determination by international standards. Their detection by molecular biology could be a useful alternative for the surveillance and control of the spread of clones circulating in hospital environments. Objective: Determine the resistance phenotype and genes expressed in the production of AmpC ß-lactamases in Gram-negative bacilli from clinical isolates in a hospital. Methods: An observational descriptive cross-sectional study was conducted. A total 78 bacterial strains were selected as carriers of AmpC ß-lactamases. Disc approximation tests were performed. The strains testing positive were selected for DNA extraction and multiplex PCR for detection of six AmpC gene families. Determination was made of the frequency per sample type, service and comparison with the susceptibility profile. Results: Of the strains selected with AmpC phenotype, 57.6 percent (45/78) were considered to be AmpC β-lactamase confirmed cases, due to their positive confirmatory test. The molecular technique used confirmed the presence of AmpC genes in 40 percent (18/45) of the cases. The gene most commonly obtained was MIR n= 9 (20 percent), followed by DHA n= 7 (15 percent). Conclusions: Timely detection of genes encoding for AmpC ß-lactamases makes it possible to set up strategies to prevent plasmid-mediated circulation in hospitals, as well as apply better therapeutic options that do not induce other resistance mechanisms(AU)

Phenotypic and genotypic characterization of plasmid-mediated AmpC beta-lactamases in enteric Gram-negative bacteria from patients with lower respiratory tract infections in a tertiary hospital, southwest Nigeria

Background: AmpC or class C or group 1 beta lactamases are class C cephalosporinases that hydrolyse a wide variety of beta-lactam antibiotics including alpha methoxy beta-lactams (cefoxitin), narrow and broad spectrum cephalosporins. This study was conducted to characterize plasmid-mediated AmpC producing enteric Gram- negative bacteria from patients with lower respiratory tract infections in Obafemi Awolowo University Teaching Hospital Complex (OAUTHC) Ile Ife, Osun State, Nigeria Methodology: A total of 149 patients with clinical features of lower respiratory tract infections (LRTI) were selected by simple random sampling for the study. All Gram-negative isolates recovered from standard microbiological cultures of respiratory specimens of these patients were tested against cefoxitin, third generation cephalosporins (3GCs), and other antibiotics using the disc diffusion AST method, and also screened for production of AmpC beta-lactamases phenotypically by the CLSI method. Plasmid DNA extraction was carried out on twenty-nine cefoxitin-resistant selected isolates using the Kado and Lin method, while genotypic detection of plasmid-mediated AmpC gene was carried out by the polymerase chain reaction (PCR) assay. Results: The results showed that 204 (43.3%) of 471 isolates recovered from the 149 selected patients were resistant to 3GC in the AST assay, among which 121 (59.3%) were resistant to cefoxitin, and 189 of the 471 isolates (40.1%) were AmpC producers. The AmpC producers concurrently showed multiple resistance pattern to other antibiotics tested in this study. Ninety six percent of the 29 selected isolates for plasmid analysis contained plasmids, 45% of which amplified positive on PCR for CMY, 38% for FOX, and 31% for ACC types of AmpC genes. Conclusion: This study showed a high degree of antibiotic resistance among enteric Gram-negative bacteria recovered from patients with LRTIs, as well as high degree of plasmid-encoded AmpC genes responsible for this high antibiotic resistance among the isolates. Proper antibiotic policy and regulation are required to limit the spread of plasmid mediated AmpC ß-lactamase

AncPhore: A versatile tool for anchor pharmacophore steered drug discovery with applications in discovery of new inhibitors targeting metallo-

We herein describe AncPhore, a versatile tool for drug discovery, which is characterized by pharmacophore feature analysis and anchor pharmacophore (

Phenotypic Demonstration of ß-lactamase (ESßLs, MßLs, and Amp-C) among MDR Pseudomonas aeruginosa isolates obtained From Burn wound infected in Yemen

In 2017, the World Health Organization published its first-ever list of antimicrobial-resistant bacteria “prioritypathogens,” a catalog of 12 families of bacteria posing the greatest threat to human health. This list focuses onthe risk of Gram-negative bacteria for multiple drug-resistant. Pseudomonas aeruginosa was at the top of the listand critical. A current study aiming to demonstrate the prevalence of β-lactamase among multidrug-resistant P.aeruginosa strains isolated from burn wound patients phenotypically. The isolates were identified then antibioticsusceptibility tested against 10 antipseudomonal agents, finally, phenotypically β-lactamase (ESβLs, MβLs, andAmp-C) production screened by combined disk diffusion test and Imipenem-ethylenediaminetetraacetic acid.Results in the current study identified 98 P. aeruginosa isolates from 200 clinical specimens obtained from burnwound patients. Our result showed 65 (66.3%) of the 98 P. aeruginosa isolates were multiple drug-resistant(MDR) strains. Out of 65 isolates, 37 (56.9%), 21 (32.3%), and 40 (61.5%) were ESβLs, MβLs, and Amp-Cproducing P. aeruginosa, respectively, according to phenotypic detection method. We found co-expression ofvarious β-lactamases. In the present study, 16 isolates showed co-existence of AmpC + ESBL, 16 isolates werehaving ESBL + MBL + AmpC, and five isolates were having co-existence of ESBL + MBL. The occurrence ofESβLs, MβLs, and Amp-C producing P. aeruginosa was demonstrated, calling for phenotypical determinationof antibiotic resistance mechanisms should be performed regularly to guide antibiotic selection during therapy.Significant conclusions drawn from this work include a rise in the rate of β-lactamase (ESβLs, MβLs, andAmp-C) in MDR P. aeruginosa. Later research should, therefore, focus on the study of molecular characterization.

Detection of Extended-Spectrum Beta Lactamases and AmpC Beta Lactamases Producing Uropathogenic Escherichia coli in a Tertiary Care Hospital

Background: The multidrug resistant among uropathogenic E. coli has become a potential threat to global health. The aim of the current study to evaluate the antimicrobial activities of nitrofurantoin and fosfomycin along with other antimicrobials against Extended Spectrum β-Lactamases (ESBL) and AmpC producer isolates from the most common organism E. coli. Methods: A total of 6046 clean catch midstream urine samples were collected and processed in Microbiology department of tertiary care hospital. The antimicrobial susceptibility of E. coli isolates was initially screened by Kirby-Bauer disk diffusion method. The resistant isolates were confirmed to be ESBL and AmpC producers by their respective phenotypic confirmatory tests of combined disc method. Results: Out of 6046 patients there were 1855 E. coli positive patients. Maximum patients in the age group of 21-30 years were 51.5% followed by 31-40 years where patients were 26%. 64.4% E. coli were isolated from female patients and 35.6% from male patients. E. coli showed higher sensitivity towards, fosfomycin (100%), imipenem (100%), nitrofurantoin (84.1%), piperacillin and tazobactam (77.3%), amikacin (76.1%) and while they showed high degree resistance pattern against Penicillin, cotrimoxazole, ciprofloxacin, norfloxacin and 2nd and 3rd generation cephalosporin. Out of 1855 E. coli, multi drug resistance was seen in 520 E. coli isolates. ESBL production was observed among 50% of E. coli isolates by combined disk method. Out of 520 isolates, 150 isolates showed resistance to one or more extended-spectrum cephalosporins and cefoxitin by Kirby-Bauer disk diffusion method. These were selected and screened for ESBL and AmpC production. Among 150 cefoxitin-resistant isolates, AmpC phenotype was detected in 100 isolates (66.6%) by AmpC disc method. The overall occurrence of AmpC in the study was found to be 19.2%. Susceptibility of ESBL and AmpC producers to fosfomycin, imipenem, nitrofurantoin and amikacin were found to be 100%, 98.5%, 89% and 75% respectively. Conclusions: There is increased prevalence of ESBL and AmpC producing E. coli. Thus, early detection of ESBL and AmpC producer E. coli by simple phenotypic methods is necessary to avoid treatment failure, where molecular techniques are not available.

Detection of Extended-Spectrum Beta Lactamases and AmpC Beta Lactamases Producing Uropathogenic Escherichia coli in a Tertiary Care Hospital

Background: The multidrug resistant among uropathogenic E. coli has become a potential threat to global health. The aim of the current study to evaluate the antimicrobial activities of nitrofurantoin and fosfomycin along with other antimicrobials against Extended Spectrum β-Lactamases (ESBL) and AmpC producer isolates from the most common organism E. coli. Methods: A total of 6046 clean catch midstream urine samples were collected and processed in Microbiology department of tertiary care hospital. The antimicrobial susceptibility of E. coli isolates was initially screened by Kirby-Bauer disk diffusion method. The resistant isolates were confirmed to be ESBL and AmpC producers by their respective phenotypic confirmatory tests of combined disc method. Results: Out of 6046 patients there were 1855 E. coli positive patients. Maximum patients in the age group of 21-30 years were 51.5% followed by 31-40 years where patients were 26%. 64.4% E. coli were isolated from female patients and 35.6% from male patients. E. coli showed higher sensitivity towards, fosfomycin (100%), imipenem (100%), nitrofurantoin (84.1%), piperacillin and tazobactam (77.3%), amikacin (76.1%) and while they showed high degree resistance pattern against Penicillin, cotrimoxazole, ciprofloxacin, norfloxacin and 2nd and 3rd generation cephalosporin. Out of 1855 E. coli, multi drug resistance was seen in 520 E. coli isolates. ESBL production was observed among 50% of E. coli isolates by combined disk method. Out of 520 isolates, 150 isolates showed resistance to one or more extended-spectrum cephalosporins and cefoxitin by Kirby-Bauer disk diffusion method. These were selected and screened for ESBL and AmpC production. Among 150 cefoxitin-resistant isolates, AmpC phenotype was detected in 100 isolates (66.6%) by AmpC disc method. The overall occurrence of AmpC in the study was found to be 19.2%. Susceptibility of ESBL and AmpC producers to fosfomycin, imipenem, nitrofurantoin and amikacin were found to be 100%, 98.5%, 89% and 75% respectively. Conclusions: There is increased prevalence of ESBL and AmpC producing E. coli. Thus, early detection of ESBL and AmpC producer E. coli by simple phenotypic methods is necessary to avoid treatment failure, where molecular techniques are not available.

Phenotypic & genotypic profile of antimicrobial resistance in Pseudomonas species in hospitalized patients

Background & objectives: Nosocomial infections caused by multidrug-resistant, Pseudomonas species have become a major clinical and public health concern. The aim of this study was to characterize phenotypic and genotypic profile of antimicrobial resistance (AMR) in Pseudomonas spp. isolated from hospitalized patients. Methods: A total of 126 consecutive, non-duplicate isolates of Pseudomonas spp. isolated from various clinical samples were included in the study over a period of two years. Identification and antimicrobial sensitivity was performed using automated culture system according to the Clinical and Laboratory Standards Institute (CLSI) recommendations. Phenotypic detection of extended-spectrum ?-lactamases (ESBLs), Amp-C ?-lactamase (AmpC) and metallo-?-lactamases (MBLs) were done by various combinations of disc-diffusion and E-test methods, followed by polymerase chain reaction-based detection of ?-lactamase-encoding genes. Results: Among 126 clinical isolates, 121 (96.1%) isolates were identified as Pseudomonas aeruginosa. Most of the isolates were recovered from pus sample, 35 (27.8%) followed by urine, 25 (19.84%); endotracheal aspirate, 24 (19.04%); blood, 14 (11.11%) and sputum, four (3.17%). The highest rate of resistance was against ticarcillin-clavulanic acid, 113 (89.7%) followed by meropenem, 92 (72.5%) and ceftazidime, 91 (72.3%). Overall, ESBLs, AmpC and carbapenemase production was detected in 109 (96.4%), 64 (50.8%) and 105 (94.6%) isolates by phenotypic methods. The most prevalent ESBL gene was blaTEMin 72 (57.1%) and the least prevalent was blaSHVin 19 (15.1%) isolates. AmpC gene was seen less compared to ESBL gene. The most prevalent carbapenemases gene was blaNDM-141 (46.06%) followed by blaVIM and blaOXA-1. Interpretation & conclusions: Our findings suggested that a high rate of ESBLs and carbapenemases production was observed in Pseudomonas spp. Therefore, phenotypic and genotypic detection of AMR needs to be combined for better characterization of resistance patterns in Pseudomonas spp.

Patrón sensibilidad/resistencia en los urocultivos de pacientes con I.T.U. que consultan a urgencias de adultos, Hospital de San José entre enero de 2014 y diciembre de 2014 / Pattern Sensitivity/Resistance in the Urocultives of Patients with U.T.I. who Consult Adult Urgencies, San Jose Hospital between January 2014 and December 2014

Introducción: La infección del tracto urinario (ITU) es un motivo de consulta frecuente en urgencias, siendo necesario el tratamiento antibiótico empírico antes de obtener un urocultivo. Objetivo Determinar el patrón de sensibilidad/resistencia de los gérmenes aislados en los urocultivos de pacientes que ingresan por urgencias de adultos con sintomatología sugestiva de ITU. Métodos Se realizó un estudio observacional, descriptivo de corte transversal, recolectando los datos de los urocultivos de pacientes con diagnóstico de ITU que asistieron por urgencias adultos, y cumplieron los criterios de inclusión en el año 2014. Resultados Se analizaron 133 pacientes (133 urocultivos), 50,4% mujeres, edad promedio de 64,1 años (DE 19,1). Se encontró una frecuencia mayor de ITU alta (54,9%), e ITU no complicada (54,1%), la mayoría de origen en la comunidad (95,5%). El germen más frecuentemente aislado fue E. coli (56,4%), seguido por Klebsiella oxytoca (7,1%). La resistencia de E. coli fue del 55,7% para ampicilina sulbactam, 58,2% para nitrofurantoina, 40% para quinolonas y 32% para cefazolina. En pacientes con factores de riesgo urológico se encontró una resistencia entre el 40% al 50%. Se evidenció patrón BLEA (12,9%), AMPc (20%) y KPC (1,4%). Conclusión Los uropatógenos han aumentado de forma significativa su resistencia a las diferentes familias de antibióticos, entre ellas las cefalosporinas y las quinolonas, confirmando que medicamentos como ampicilina sulbactam, nitrofurantoina, y ciprofloxacina no están indicados en el manejo empírico de ITU en nuestra institución, especialmente al presentar factores de riesgo urológicos.

Introduction Urinary tract infection (UTI) is a frequent cause for assistance to the emergency services, in most cases is necessary initiate empirical antimicrobial management while obtaining the result of the uroculture. Therefore, it is vital to know the pattern of sensitivity/resistance of the most frequent uropathogens and thus offer the best initial treatment. Objective To determine the pattern of sensitivity / resistance of isolated germs in the urine cultures of adults patients admitted to the emergency room with UTI suggestive symptoms. Methods An observational, descriptive, cross-sectional study was conducted, collecting urine culture data from patients diagnosed with UTI who were attended in adult emergencies in 2014. Results A total of 133 patients were analyzed (133 urine cultures), 50.4% were women, with average age of 64.1 years (SD 19.1). Higher frequency of high urinary tract infection was found (54.9%), and uncomplicated UTI (54.1%), most UTI originated in the community (95.5%). The most frequently isolated germ was E. coli (56.4%), followed by Klebsiella oxytoca (7.1%). The resistance of E. coli was 55.7% for ampicillin sulbactam, 58.2% for nitrofurantoin, 40% for quinolones and 32% for cefazolin. In patients with urological risk factors, resistance was found between 40% and 50%. BLEA pattern (12.9%), cAMP (20%) and KPC (1.4%) were evidenced. Conclusion Uropathogens have significantly increased their resistance to different families of antibiotics, including cephalosporins and quinolones, confirming that drugs such as ampicillin sulbactam, nitrofurantoin, and ciprofloxacin are not indicated in the empirical management of UTI in our institution, especially with the presence of urological risk factors.

Identification Of Non– Fermenter Gram Negative Bacilli (NFGNB) From Various Clinical Isolates With Special Reference To Carbapenem Resistance In Various Isolates.

Non Fermenter Gram negative bacilli (NFGNB) has emerged as important hospital pathogens they are more significant as they are found to be multi drug resistant. Resistance to carbapenems is common among NFGNB. AIMS & OBJECTIVES: To isolate & identify NFGNB from various clinical samples and to detect resistance to carbapenem in isolates resistant to Imipenem. MATERIAL & METHOD: NFGNB isolated from various samples were speciated using standard tests. Isolates resistant to Imipenem were subjected to detection of MBLs(Metallo-β-lactmase) and Amp-C. RESULTS: Out of 1566 samples received, NFGNB were 200. Among them 112 were Pseudomonas aeruginosa from which 31 were found to be resistant to Imipenem, of which 3 were MBLproducer by Modified Hodge test while 4 were MBLproducer by EDTAdisc synergy test. Out of 200 NFGNB 71 were Acinetobacter baumanii, of which 23 were found to be resistant to Imipenem, of which 6 were MBLproducer by Modified Hodge test, while 4 were seen to be MBL producer by EDTAdisc synergy test. Nineteen isolates of Acinetobacter baumanii were found to be resistant to cefoxitin of which 6 were found to be Amp-C producer by Amp-c disc test. None of the Pseudomonas aeruginosa were Amp-C producer. Other NFGNB isolated were either sensitive to Imipenem or if resistant were not MBLor Amp-C producer.

Assessment of Antimicrobial Resistance in the Food Chains in Norway

The Norwegian Food Safety Authority (NFSA) asked the Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM) for an assessment of antimicrobial resistance (AMR) in the food chains in Norway, with focus on each of the following food chains: pigs and pork products; poultry, eggs and poultry products; cattle and bovine products; aquaculture and aquaculture products; fresh produce (fruit, berries, and vegetables); and drinking water. AMR in imported food has not been assessed in this report. AMR in Norwegian food chains has been assessed in terms of probability of exposure to humans. Due to data constraints, it has not been possible to assess the consequences of this exposure for human health. VKM appointed a working group consisting of three members of the Panel on Biological Hazards, one member of Panel on Animal Health and Welfare, and four external experts to prepare a draft Opinion document and the answer the questions. The Panel on Biological Hazards has reviewed and revised the draft prepared by the working group and approved the Opinion document «Assessment of antimicrobial resistance in the food chains in Norway”. AMR can be described as the ability of a bacterium to withstand the effects of an antimicrobial. The clinical antimicrobial resistance crisis has focused attention on all uses of antimicrobial agents, including their use in human medicine, veterinary medicine, and in agriculture and aquaculture. AMR is considered the greatest challenge to face health care in 21st century, and there is increasing concern and debate about which roles the food production chains play as reservoirs and disseminators of AMR. This assessment addresses several food chains. The report does not characterise all forms of AMR that may occur in these chains, but puts emphasis on the resistant bacteria and resistance determinants that have emerged at the animal-human interface in recent decades. VKM’s choice is based on zoonotic potential and the limited alternatives available for treatment of infections. In order for a comprehensive and detailed assessment to be conducted, these particular resistance forms need to be characterised and assessed separately. At an overall level, the hazard regarding exposure of humans to antimicrobial resistant bacteria from cattle, milk/milk products, fish/fish products/seafood, fresh produce, water, and food processing in Norway is considered by VKM to be negligible. Current data regarding possible pathways for transmission of LA-MRSA via contaminated food/meat to the broader human population fail to implicate LA-MRSA from pigs as a foodborne pathogen. Compared with other animal products, poultry and poultry products are regarded as the most important reservoirs of ESBL/AmpC-producing Enterobacteriaceae, quinolone-resistant E. coli (QREC), and their corresponding resistance determinants. The probability of human exposure of ESBL/AmpC-producing Enterobacteriaceae and QREC via poultry is assessed as being non-negligible. Probability of AMR Transfer Associated with Food and Uncertainties: In this assessment, the probability of transmission of AMR from food chains to humans has been either categorized as negligible or non-negligible according to the following definitions: Negligible – the probability of transfer of AMR is extremely low. Negligible probability should be considered insignificant. Non-negligible – the probability of transfer of AMR is greater than negligible. Non-negligible probability should be considered significant, but the available data are currently insufficient to enable discrimination between the different levels. Lack of data has made it difficult to reach any firm conclusions regarding the probability of AMR transmission from food to humans in Norway. Similarly, ranking the probabilities with regard to relative importance is largely not possible with the data available. The probability of transfer of AMR from cattle, milk/milk products, fish, seafood, and drinking water has been assessed to be negligible. The probability of transfer of LA-MRSA from live pigs to humans is considered to be non-negligible, while the probability of transfer from pork to humans has been assessed to be negligible. The probability of transfer of ESBL/AmpC-producing Enterobacteriaceae, quinolone-resistant E. coli, and their respective corresponding genes from live poultry and poultry meat is considered as non-negligible. Processing of food, such as cooking or preservation, can reduce the number of bacteria in the products and thus decrease the transmission of antimicrobial resistant bacteria from food to humans. It should be noted that both categories of probabilities (negligible and non-negligible) in this assessment are associated with a number of uncertainties. Bacteria are living organisms that are under continuous evolution, and are able to adapt rapidly to changing living conditions. This report is an assessment of the current situation with regards to development and dissemination of antibiotic resistant bacteria and their resistance genes in the food chain. This situation may change as the bacteria continue to adapt to the selection pressures exerted by the worldwide use of antimicrobials. Such bacterial changes, sometimes occurring VKM Report 2015:29 9 in “quantum leaps” due to horizontal gene transfer (HGT), may also rapidly change the probability of transfer of resistance to specific antimicrobials. Data Gaps: There is a lack of knowledge regarding the vast reservoir of AMR in the environmental, animal, and food reservoirs. Furthermore, there is lack of data regarding the routes and frequencies of transmission of AMR from live, food-producing animals and foodstuffs of different origins to humans and vice versa.

Association of furanone C-30 with biofilm formation & antibiotic resistance in Pseudomonas aeruginosa

Background & objectives: Pseudomonas aeruginosa is an opportunistic pathogen that can cause nosocomial bloodstream infections in humans. This study was aimed to explore the association of furanone C-30 with biofilm formation, quorum sensing (QS) system and antibiotic resistance in P. aeruginosa. Methods: An in vitro model of P. aeruginosa bacterial biofilm was established using the standard P. aeruginosa strain (PAO-1). After treatment with 2.5 and 5 ?g/ml of furanone C-30, the change of biofilm morphology of PAO-1 was observed, and the expression levels of QS-regulated virulence genes (lasB, rhlA and phzA2), QS receptor genes (lasR, rhlR and pqsR) as well as QS signal molecule synthase genes (lasI, rhlI, pqsE and pqsH) were determined. Besides, the AmpC expression was quantified in planktonic and mature biofilm induced by antibiotics. Results: Furanone C-30 treatment significantly inhibited biofilm formation in a dose-dependent manner. With the increase of furanone C-30 concentration, the expression levels of lasB, rhlA, phzA2, pqsR, lasI, rhlI pqsE and pqsH significantly decreased in mature biofilm bacteria while the expression levels of lasR and rhlR markedly increased. The AmpC expression was significantly decreased in both planktonic and biofilm bacteria induced by imipenem and ceftazidime. Interpretation & conclusions: Furanone C-30 may inhibit biofilm formation and antibiotic resistance in P. aeruginosa through regulating QS genes. The inhibitory effect of furanone C-30 on las system appeared to be stronger than that on rhl system. Further studies need to be done with different strains of P. aeruginosa to confirm our findings.

Clonal relation and antimicrobial resistance pattern of extended-spectrum ß-lactamase- and AmpC ß-lactamase-producing Enterobacter spp. isolated from different clinical samples in Tehran, Iran

Abstract INTRODUCTION: Here, we determined the genes encoding antibiotic resistance enzymes and virulence factors and evaluated the genetic relationship between Enterobacter spp. isolated from different clinical samples. METHODS: A total of 57 clinical isolates of Enterobacter spp. were tested for the production of extended-spectrum β-lactamases (ESBLs), carbapenemase, and AmpC using phenotypic and genotypic methods. RESULTS: The most common ESBLs and AmpC β-lactamases were bla TEM (63.3%) and bla EBC (57.7%), respectively. The most prevalent virulence gene was rpos (87.7%). The random amplified polymorphic DNA (RAPD) patterns of strains were genetically unrelated. CONCLUSIONS: RAPD polymerase chain reaction analysis revealed high genetic diversity among isolates.

Clonal relationships, antimicrobial susceptibilities, and molecular characterization of extended-spectrum beta-lactamase-producing Escherichia coli isolates from urinary tract infections and fecal samples in Southeast Iran

Abstract INTRODUCTION: Multidrug-resistant (MDR) Escherichia coli, a species that is a leading cause of urinary tract infections (UTIs) and is a major global public health concern. This study was designed to detect the differences in antibiotic resistance patterns, the production and type of extended spectrum β-lactamases (ESBLs), and the clonal relationships among E. coli isolates from UTIs and fecal samples. METHODS: Antibacterial resistance was determined by the disk diffusion method. ESBL, carbapenemase, and AmpC-producing isolates were detected phenotypically. Then, the ESBL genes were sequenced to detect the type. Enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) was performed on the ESBL-positive isolates. RESULTS: The most common effective antibacterial agents were colistin, imipenem, and amikacin. Among the isolates, 204 (56.6%) were MDR. Of the 163 ESBL-positive isolates, 11 (6.7%) produced AmpC, and the frequencies of beta-lactamase-positive genes were as follows: bla CTX-Mgroup1, 76%; bla TEM1, 74.8%; bla SHV12, 1.2%; and bla OXA1, 12.88%. ERIC PCR showed a diverse pattern, suggesting that clonal spread of E. coli in this area is uncommon, and that most of the infecting strains are endogenous. CONCLUSIONS: The high rates of antibacterial-resistant and MDR isolates are quite important since these strains can act as source of resistant bacteria that can be spread in the community. Controlling antibiotic use, against inappropriate use and abuse, in the community and continuous surveillance of emerging resistance traits are critical to controlling the spread of resistance.

Biological and Genetic Characteristics of Clinically Isolated Enterobacter cloacae with Multidrug Resistance

BACKGROUND: From January 2014 to December 2015, 69 clones of Enterobacter cloacae showing multidrug resistance to six classes of antimicrobial agents were collected from two medical centers in Korea. METHODS: Minimum inhibitory concentrations were determined using the E-test method, and 17 genes were detected using polymerase chain reaction (PCR). The epidemiological relatedness of the strains was identified using repetitive element sequence-based PCR and multilocus sequence typing. RESULTS: The 69 E. cloacae clones produced extended spectrum β lactamase (ESBL) and AmpC and showed multidrug resistance to cefotaxime, ceftazidime, and aztreonam. We identified the following sequence types: ST56 of type VI for ESBL SHV (N=12, 17.4%); ST53, ST114, ST113, and ST550 of types I, IV, VI, and VII, respectively, for CTX-M (N=11, 15.9%); and ST668 of type III for the carbapenemase NDM gene (N=1, 1.5%). The AmpC DHA gene (N=2, 2.89%) was confirmed as ST134, although its type was not identified, whereas EBC (MIR/ACT; N=18, 26.1%) was identified as ST53, ST24, ST41, ST114, ST442, ST446, ST484, and ST550 of types V, I, III, IV, VII, and VI, respectively. The formed subclasses were bla CTX-M-3 and bla CTX-M-22 by CTX-M-1, bla CTX-M-9 and bla CTX-M-125 by CTX-M-9, bla DHA-1 by DHA, and bla MIR-7 and bla ACT-15,17,18,25,27,28 by EBC (MIR/ACT). CONCLUSIONS: There were no epidemiological relationships between the gene products and the occurrence of resistance among the strains.

Phenotypic and Genomic Characterization of AmpC-Producing Klebsiella pneumoniae From Korea

The prevalence of multidrug-resistant gram-negative bacteria has continuously increased over the past few years; bacterial strains producing AmpC β-lactamases and/or extended-spectrum β-lactamases (ESBLs) are of particular concern. We combined high-resolution whole genome sequencing and phenotypic data to elucidate the mechanisms of resistance to cephamycin and β-lactamase in Korean Klebsiella pneumoniae strains, in which no AmpC-encoding genes were detected by PCR. We identified several genes that alone or in combination can potentially explain the resistance phenotype. We showed that different mechanisms could explain the resistance phenotype, emphasizing the limitations of the PCR and the importance of distinguishing closely-related gene variants.

Analysis of Clinical Distribution and Drug Resistance of Non-sputum Specimen AmpC Enzyme-producing Enterobacter cloacae in a Hospital during 2011-2017 / 中国药房

OBJECTIVE:To provide reference for rational drug use and hospital infection control. METHODS:AmpC enzyme-producing Enterobacter cloacae were isolated from non-sputum specimen of a hospital during Jan. 2011-Oct. 2017. Drug sensitivity test was conducted by using MIC. The situation of AmpC enzyme production was confirmed by three dimensional test, and that of ESBLs-producing stain was detected with double-disk synergy test. RESULTS:There were 546 strains of AmpC enzyme-producing E. cloacae isolated from non-sputum specimen of the hospital,accounting for 4.80% of non-sputum specimen (546/11 375)and 38.97% of E. cloacae(546/1 401). Top 3 non-sputum samples in the list of detection rate were wound secretion (27.29%),midstream urine(25.82%)and blood(21.79%),and the departments with high detection rate were ICU(22.89%), neurosurgery department(18.68%)and general surgery department(16.67%). Resistance rate of AmpC enzyme-producing E. cloacae to most commonly used antibiotics was higher than 40%. There was statistical significance in resistant rate of the bacteria to ceftriaxone, cefotaxime, gentamicin, nitrofurantoin, levofloxacin, piperacillin/tazobactam, cefoperazone, ceftazidime,cefepime,tobramycin and minocycline among different years (P<0.05). The resistant rate to imipenem and meropenem was lower than 2%. Among 546 strains of AmpC enzyme-producing E. cloacae,68 strains of ESBLs were detected,and detection rates were 5.77%,6.06%,8.70%,10.26%,13.79%,17.35%,18.75% during 2011-2017. CONCLUSIONS:AmpC enzyme-producing E. cloacae are mainly isolated from samples as wound secretion and midstream urine,and mainly come from ICU and neurosurgery department. The drug resistance of the bacteria is severe,and drug resistance of the bacteria to antibiotics as β-lactams and quinolones is increased significantly. The detection rate of ESBLs-producing strain increases year by year. The bacteria are sensitive to carbapenems antibiotics,which can be regarded as first choice. It is necessary to strengthen drug resistance and enzyme production monitoring of AmpC enzyme-producing E. cloacae,select antibiotics combined with results of drug sensitivity test so as to prevent or delay the rapid increase of its resistance rate.

Multidrug resistance mediated by co‑carriage of extended‑spectrum beta‑lactamases, AmpC and New Delhi metallo‑beta‑lactamase‑1 genes among carbapenem‑resistant Enterobacteriaceae at five Indian medical centres.

In this study, we evaluated the coexistence of extended‑spectrum beta‑lactamases (ESBL), AmpC and New Delhi metallo‑beta‑lactamase‑1 (NDM‑1) genes among carbapenem‑resistant Enterobacteriaceae (CRE) recovered prospectively from patients at multiple sites. The study included 285 CRE strains from 2782 Gram‑negative Bacilli collected from multiple centres during 2007–2010, of which 87 were characterised. Standard and reference laboratory methods were used for resistance determination. Detection of blaNDM‑1, blaAmpC, blaTEM, blaSHV and blaCTX‑M was done by polymerase chain reaction. High levels of antimicrobial resistance observed among study isolates. Co‑carriage of ESBLs, AmpC and NDM‑1 was 26.3%. Nosocomial origin among the co‑carriage isolates was 64.3%, with 9.2% associated mortality.

Carriage of ESBL and AmpC-Positive Enterobacteriaceae in Gastrointestinal Tract of Healthy Community Subjects and Hospitalized Patients and Detection of blaCTX-M Gene in ESBL Positive Isolates.

Aim: The study aimed at analyzing ESBL and AmpC positive Enterobacteriaceae in the gastrointestinal tracts of healthy community subjects and hospitalized patients and detection of blaCTX-M type gene in ESBL positive isolates. Methods: Bacteria were isolated from stool samples of the study population. Production of ESBL-type beta-lactamases was screened by double-disk synergy test as well as automated system, and AmpC enzyme production was detected by the AmpC disk test. ESBL positive isolates were subjected to detection of the blaCTX-M gene. Results: A total of 792 stool samples (50% from healthy subjects and 50% from hospitalized patients) were studied. The prevalence rates of ESBL-positive Enterobacteriaceae were 9.3% in hospitalized patients and 4.4% in healthy community subjects. Production of the AmpC enzyme was detected in