Detection of blaNDM-1 gene in ESBL producing Escherichia coli and Klebsiella pneumoniae isolated from urine samples.

INTRODUCTION: Enterobacteriaceae such as Escherichia coli and Klebsiella pneumoniae are the most prominent bacterial species resistant to almost all commonly used antibiotics. Carbapenem is one of the last resort drugs for treating such emerging multidrug-resistant bacteria. This study aimed to detect carbapenem-resistant blaNDM-1 gene in ESBL producing E. coli and K. pneumoniae isolates. METHODOLOGY: A total of 190 E. coli and 350 K. pneumoniae isolates were screened for extended spectrumß-lactamase (ESBL), carbapenemase and metallo ß-lactamase (MBL) production via double-disk synergy test (DDST), modified Hodge test and combined-disk diffusion method. The blaNDM-1 gene was detected by PCR and confirmed via Sanger sequencing method. RESULTS: Of the 540 isolates tested, 71.8% were found to be multidrug-resistant. Overall rate of ESBL-positive isolates were 57.89% E. coli and 31.42% K. pneumoniae. Among ESBL positive isolates, 49.09% E. coli and 40% K. pneumoniae were positive for carbapenemase production whereas MBL production was detected in 29% E. coli and 22% K. pneumoniae isolates. In MBL positive isolates, (37%) E. coli and (40%) K. pneumoniae isolates harboured blaNDM-1 gene. The pair-wise DNA was aligned with the NDM-1 sequence from GenBank. The alignment score was 243 and the blast nucleotide sequencing results showed 97% sequence similarity with the sequences in GenBank for the blaNDM-1 gene. CONCLUSIONS: The blaNDM-1 gene was found to be the most prevalent in urine samples. There is a dire need to conduct screening tests in hospitals and communities to find out the exact prevalence of the blaNDM-1 spread in our population.

Presence of fimH and afa genes in urinary isolates of extended-spectrum beta-lactamases producing Escherichia coli in Lima, Peru. / Presencia de genes fimH y afa en aislamientos urinarios de Escherichia coli productora de betalactamasas de espectro extendido en Lima, Perú.

Descriptive study conducted in order to determine the presence of the fimH and afa genes in urinary isolates of extended-spectrum beta-lactamases (ESBL) producing Escherichia coli. Isolates from project TO-06/09 of the Instituto Nacional de Salud del Niño in Lima, Peru were used. A total of 75 urinary isolates of Escherichia coli were included. Gene identification was performed by polymerase chain reaction. From the 75 isolates, 74 (98.7%) were positive for the fimH gene and 6 (8.0%) were positive for the afa gene. Virulence factors produced by the fimH and afa genes were evident in urinary isolates of ESBL producing Escherichia coli.

Con el objetivo de determinar la presencia de los genes fimH y afa en aislamientos urinarios de Escherichia coli productoras de betalactamasas de espectro extendido (BLEE), se realizó un estudio descriptivo, con aislamientos del cepario del proyecto TO-06/09 del Instituto Nacional de Salud del Niño en Lima, Perú. Se incluyeron 75 aislamientos urinarios de Escherichia coli. La identificación de genes se realizó por reacción en cadena de la polimerasa. De los 75 aislamientos, 74 (98,7%) fueron positivos para el gen fimH y 6 (8,0%) fueron positivos para el gen afa. Se evidenció la presencia de los factores de virulencia producidos por los genes fimH y afa en aislamientos urinarios de Escherichia coli productoras de BLEE.

Presencia de genes fimH y afa en aislamientos urinarios de Escherichia coli productora de betalactamasas de espectro extendido en Lima, Perú / Presence of fimH and afa genes in urinary isolates of extended-spectrum beta-lactamases producing Escherichia coli in Lima, Peru

RESUMEN Con el objetivo de determinar la presencia de los genes fimH y afa en aislamientos urinarios de Escherichia coli productoras de betalactamasas de espectro extendido (BLEE), se realizó un estudio descriptivo, con aislamientos del cepario del proyecto TO-06/09 del Instituto Nacional de Salud del Niño en Lima, Perú. Se incluyeron 75 aislamientos urinarios de Escherichia coli. La identificación de genes se realizó por reacción en cadena de la polimerasa. De los 75 aislamientos, 74 (98,7%) fueron positivos para el gen fimH y 6 (8,0%) fueron positivos para el gen afa. Se evidenció la presencia de los factores de virulencia producidos por los genes fimH y afa en aislamientos urinarios de Escherichia coli productoras de BLEE.

ABSTRACT Descriptive study conducted in order to determine the presence of the fimH and afa genes in urinary isolates of extended-spectrum beta-lactamases (ESBL) producing Escherichia coli. Isolates from project TO-06/09 of the Instituto Nacional de Salud del Niño in Lima, Peru were used. A total of 75 urinary isolates of Escherichia coli were included. Gene identification was performed by polymerase chain reaction. From the 75 isolates, 74 (98.7%) were positive for the fimH gene and 6 (8.0%) were positive for the afa gene. Virulence factors produced by the fimH and afa genes were evident in urinary isolates of ESBL producing Escherichia coli.

An Enzyme-Mediated Amplification Strategy Enables Detection of ß-Lactamase Activity Directly in Unprocessed Clinical Samples for Phenotypic Detection of ß-Lactam Resistance.

Biochemical assays that can identify ß-lactamase activity directly from patient samples have the potential to significantly improve the treatment of bacterial infections. However, current ß-lactamase probes do not have the sensitivity needed to measure ß-lactam resistance directly from patient samples. Here, we report the development of an instrument-free signal amplification technology, DETECT, that connects the activity of two enzymes in series to effectively amplify the activity of ß-lactamase 40 000-fold, compared to the standard ß-lactamase probe nitrocefin.

Comparative characteristic of antimicrobial resistance in geriatric hospital: a retrospective cohort study.

BACKGROUND AND AIMS: To examine antimicrobial resistance of commonly isolated pathogens in elderly hospitalized patients. METHODS: Data regarding all clinically significant isolates from blood and urine cultures of patients admitted to a multilevel geriatric hospital during March 2015 to April 2016 were collected. Antimicrobial susceptibility testing was performed according to Clinical and Laboratory Standard Institute guidelines. RESULTS: Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae were the most common isolates, with proportions of extended spectrum beta-lactamase positivity of 60, 40, and 61% respectively. Adjusted logistic regression models indicated that resistance of Escherichia coli to ceftriaxone [odds ratio (OR) 2.8, 95% confidence interval (CI) 1.5-5.1], ceftazidime (OR 2.8, 95% CI 1.5-5.1), ciprofloxacin (OR 2.2, 95% CI 1.2-4.0), amoxicillin/clavulanic acid (OR 2.3, 95% CI 1.2-4.3), and trimethoprim/sulfamethoxazole (OR 2.4, 95% CI 1.4-4.3) was significantly higher in skilled nursing wards than in acute geriatric wards. Resistance of Proteus mirabilis to ceftriaxone (OR 3.1, 95% CI 1.5-6.4) and Klebsiella pneumoniae to ciprofloxacin (OR 3.2, 95% CI 1.3-7.9) was significantly higher in skilled nursing wards than in acute wards. CONCLUSIONS AND DISCUSSION: Antimicrobial resistance was found to be high in a multilevel geriatric hospital, especially in skilled nursing wards. These findings call for rethinking of the empirical antimicrobial therapy and of the efforts for prevention of nosocomial infection.

AmpC and extended spectrum beta-lactamases production among urinary isolates from a tertiary care hospital in Lalitpur, Nepal.

BACKGROUND: Production of AmpC and extended spectrum beta-lactamases among urinary isolates has created a serious problem to the successful management of the urinary tract infection. The main purpose of this study was to determine the rates of the extended spectrum beta-lactamase (ESBL) production and AmpC beta-lactamase (ABL) production among urinary isolates. RESULTS: Among total 564 urinary isolates, 514 (91.1%) were gram negative bacilli and 50 (8.9%) were gram positive cocci. E. coli (76.1%) was the most common bacteria isolated. Staphylococcus aureus (6.7%) was the predominant gram positive bacteria isolated. 35 (6.8%) of the 514 gram negative bacilli were ESBL producers. Similarly, 14 (2.7%) of the gram negative bacilli were ABL producers. Only one isolate was ESBL and ABL co-producer. Highest rate of susceptibility of gram negative bacteria was seen toward amikacin (97.3%) followed by imipenem (94.4%). Similarly, highest rate of susceptibility among gram positive cocci was seen toward vancomycin (100%) followed by amikacin (93.5%). CONCLUSIONS: Low rates of AmpC and extended spectrum beta-lactamases production in comparison to other previous studies were reported. On the basis of the antimicrobial susceptibility patterns of the bacteria we reported in our study, amikacin, imipenem and nitrofurantoin can be used for the preliminary treatment of urinary tract infections caused by gram negative bacteria and vancomycin and amikacin for treatment of urinary tract infections caused by gram positive bacteria.

Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae-Related Urinary Tract Infection in Kidney Transplant Recipients: Risk Factors, Treatment, and Long-Term Outcome.

BACKGROUND: Prevalence of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) has risen in kidney transplant (KT) patients, with no long-term data so far on graft function or survival. METHODS: KT patients with ESBL-E-positive urine culture were retrospectively analyzed regarding initial adequate antimicrobial therapy, recurrent infection, transplant function, and survival compared with an ESBL-E-negative KT control cohort. RESULTS: ESBL-E-positive KT patients (n = 93) were older (55.5 ± 16.1 vs 49.5 ± 16.8 y; P = .001), presented with higher trough levels of cyclosporine and tacrolimus (121 ± 71 vs 102 ± 32 ng/mL [P = .04]; and 7.9 ± 3.3 vs 7.0 ± 2.3 ng/mL [P = .04], respectively), higher dosages of mycophenolate (1,533 ± 670 vs 1,493 ± 436; P = .001), and more acute rejection episodes within 3 months before diagnosis (12.9% vs 0.8%; P < .0001) compared with control subjects (n = 591). Five-year patient survival was superior in control subjects compared with ESBL-E-positive patients (91.2% vs 83.5%; P = .034) but long-term graft function was similar. Hospitalization rates were higher in patients presenting with ESBL-E-related urinary tract infection (UTI) compared with control subjects with ESBL-E-negative UTI (60.3% vs 31.3%; P = .002) but 5-year graft survival was superior in patients presenting with ESBL-E-related UTI (88.6% vs 69.8%; P = .035) compared with control subjects with ESBL-E-negative UTI. Recurrence rates were similar in patients with or without ESBL-E-related UTI. Initial antibiotic treatment was adequate in 41.2% of patients presenting with ESBL-E-related urosepsis, resulting in a reevaluation of antibiotic stewardship in our clinic. CONCLUSIONS: ESBL-E detection in general was associated with higher mortality, but graft survival in patients with ESBL-E-related UTI was significantly better compared with ESBL-E-negative UTI.

Extended-spectrum ß-lactamase (ESBL) detection directly from urine samples with the rapid isothermal amplification-based eazyplex® SuperBug CRE assay: Proof of concept.

A commercially available assay (eazyplex® SuperBug CRE) detecting the most common carbapenemase and ESBL types was evaluated directly on 50 urine samples. Eazyplex® correctly detected ESBL-encoding genes in all 30 urine samples with confirmed ESBL production (sensitivity 100%). Two specimens showed invalid and one specimen false-positive results (specificity 97.9%).

Prevalencia de Escherichia coli productor de betalactamasas de espectro extendido (BLEE) y otras resistencias en urocultivos en un hospital general de Ica, Perú / Prevalence of Escherichia coli producing extended-spectrum beta-lactamase (ESBL) and other resistance urinecultures at a general hospital in Ica, Peru

Objetivo: Determinar la prevalencia de Escherichia coli BLEE y otras resistencias en urocultivos realizados en el Hospital Regional de Ica, durante el periodo 2013 al 2014. Materiales y métodos: Estudio descriptivo, observacional y retrospectivo que comprendió el estudio de 2792 urocultivos realizados durante el periodo 2013 y 2014 en el Hospital Regional de Ica, de los cuales se recolectó información. Los análisis se realizaron usando la estadística descriptiva y la prueba chi2 con un nivel de confianza del 95% (p<0,05). Resultados: La prevalencia de Escherichia coli BLEE fue de 4% hallando asociación signficativa con sexo y servicio hospitalario. Se identificó que la población positiva a E. coli BLEE se encontraba mayormente en mujeres (78%) así como el servicio hospitalario con mayor positividad fue medicina interna con un 54% de frecuencia, el grupo etario donde esta infección fue más frecuente estuvo comprendido entre 30 y 59 años, sin embargo no mostró significancia estadística. Se halló un predominio de resistencia a cefalosporinas como la ceftriaxona (60%), mientras que en otras resistencias fue predominante la gentamicina (88%) seguido por sulfatrimetropin (74%). Conclusión: La prevalencia de Escherichia coli BLEE y el tipo de resistencia a los antibióticos reportados en este estudio sugieren la presencia de una cepa de Escherichia coli BLEE diferente a las reportadas en nuestro país, por lo que se sugiere mayor investigación ya que es un serio problema de salud pública. (AU)

Objective: To determine the prevalence of Escherichia coliand ESBL resistance in other cultures made in the Ica Regional Hospital during the period 2013 to 2014. Materials and methods: retrospective observational study involving 2792 study cultures made during the period 2013 and 2014 in the Regional Hospital of Ica, of which data were collected. Analyses were performed using descriptive statistics and chi 2 test with a confidence level of 95% (p <0.05).Results: The prevalence of Escherichia coli ESBL was 4% finding signficativa association with sex and hospitable service. It was identified that the positive E. coli ESBL population was mostly women (78%) and hospital services more positivity was internal medicine with 54% frequency, the age group where the infection was most common was between 30 and 59, but did not show statistical significance. a predominance of cephalosporin resistance as ceftriaxone (60%) was found,where as in other gentamicin resistance was predominantly (88%) followed by sulfatrimetropin (74%).Conclusion: The prevalence of E. coli ESBL and type of antibiotic resistance reported in this study suggest the presence of a strain of E. coli other than those reported in our country ESBL, so further research is suggested because it is a serious public health problem. (AU)

Molecular epidemiology and clinical implications of metallo-ß-lactamase-producing Pseudomonas aeruginosa isolated from urine.

We conducted a study on molecular epidemiology and clinical implications of metallo-beta-lactamase (MBL)-producing Pseudomonas aeruginosa isolated from urine. Over a 10-year period from 2001 through 2010, a total of 92 MBL-producing P. aeruginosa urine isolates were collected from patients (one isolate per patient) who were admitted to 5 hospitals in Okayama Prefecture, Japan. When cross-infection was suspected in the hospital, pulsed-field gel electrophoresis was performed. In the resulting dendrogram of 79 MBL-producing P. aeruginosa urine isolates, no identical isolates and 7 pairs of isolates with >80% similarity were found. The biofilm-forming capabilities of 92 MBL-producing P. aeruginosa urine isolates were significantly greater than those of 92 non-MBL-producing urine isolates in a medium of modified artificial urine. The imipenem resistance transferred in 16 of 18 isolates tested, and these frequencies were in the range of 10⁻³ to 10⁻9. All of 18 isolates tested belonged to internationally spread sequence type 235 and had 3 gene cassettes of antimicrobial resistance genes in the class 1 integron. The strong biofilm-forming capabilities of MBL-producing P. aeruginosa urine isolates could be seriously implicated in nosocomial infections. To prevent spread of the organism and transferable genes, effective strategies to inhibit biofilm formation in medical settings are needed.

Outbreak of NDM-1-producing Enterobacteriaceae in northern Italy, July to August 2011.

Between July 2011 and August 2011, the New Delhi metallo-beta-lactamase 1 (NDM-1) gene was detected in Klebsiella pneumoniae and Escherichia coli isolates obtained from six patients hospitalised in four healthcare facilities in northern Italy. The patient who had been hospitalised in New Delhi, India, from February to May 2011 and subsequently in the Bologna area, Italy, from May to July 2011, may have been the source of the outbreak. Our findings suggest ongoing spread of this carbapenem-resistance gene in Italy and highlight the need for intensive surveillance.

Extended-spectrum ß-lactamase-producing Escherichia coli strains in the feces of carriers contribute substantially to urinary tract infections in these patients.

INTRODUCTION: The current increase in the incidence of urinary tract infections (UTIs) worldwide caused by extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli may be due to the high number of ESBL-producing Enterobacteriaceae carriers in the community. However, whether ESBL-producing bacteria can cause UTIs in carriers remains uncertain. MATERIALS AND METHODS: In this study, 21 fecal carriers of ESBL-producing Enterobacteriaceae were assessed for UTIs caused by ESBL-producing E. coli. Bacterial isolates obtained from patients' urine and stool specimens were phenotypically and genotypically examined. Clonal similarities of isolates were assessed by multilocus sequence typing (MLST) and random amplified polymorphic DNA (RAPD) fingerprinting. RESULTS: The study revealed that 9 of 21 carriers developed UTIs, and genetic analysis showed that 44% of the UTIs developed were caused by the same ESBL-producing E. coli as that found in the feces of the patients. CONCLUSIONS: The ESBL-producing E. coli in carriers can cause UTIs.

Extended-spectrum ß-lactamase-producing Gram-negative pathogens in community-acquired urinary tract infections: an increasing challenge for antimicrobial therapy.

BACKGROUND: Extended-spectrum ß-lactamases (ESBLs) are an increasing challenge in the treatment of urinary tract infections (UTIs), and also in the community. We aimed to investigate the characteristics of patients with UTIs due to ESBL-producing Escherichia coli and to assess the risk factors for ESBLs in community-acquired isolates. METHODS: We performed a retrospective study from January 1, 2007 to December 31, 2009 at a tertiary care teaching hospital in Switzerland, comparing patients with community-acquired versus healthcare-associated UTIs due to ESBL-producing E. coli. Additionally, we investigated the antimicrobial susceptibility of these isolates. RESULTS: A total of 123 patients were studied, of whom 79 (64%) had community-acquired and 44 (36%) had healthcare-associated UTIs. Community-acquired isolates were associated with acute uncomplicated UTIs (odds ratio [OR] 6.62, 95% confidence interval [CI] 1.83-36.5, P < 0.001). Risk factors were recurrent UTI (OR 3.04, 95% CI 1.14-9.14, P = 0.022) and female sex (OR 2.46, 95% CI 1.01-6.08). Community-acquired ESBL-producing E. coli urinary isolates showed high resistance rates to most of the currently used oral antimicrobial agents, including ß-lactam antibiotics (amoxicillin-clavulanic acid, 69.6% resistance), quinolones (ciprofloxacin, 84.8% resistance; norfloxacin, 83.9% resistance), and trimethoprim-sulfamethoxazole (75.9% resistance), except for nitrofurantoin (15% resistance) and fosfomycin (0% resistance). CONCLUSION: UTI due to ESBL-producing E. coli are emerging, and also in a country with low antibiotic use. Because of increasing antibiotic resistance rates of E. coli to current standard therapy and because of the resistance patterns of ESBL-producing E. coli, guidelines for the management of UTIs must be revised. Fosfomycin or nitrofurantoin are recommended for the first-line empirical oral treatment of community-acquired uncomplicated UTIs.

New Delhi metallo-ß-lactamase-1: local acquisition in Ontario, Canada, and challenges in detection.

New Delhi metallo-ß-lactamase-1 (NDM-1) is a recently identified metallo-ß-lactamase that confers resistance to carbapenems and all other ß-lactam antibiotics, with the exception of aztreonam. NDM-1 is also associated with resistance to many other classes of antibiotics. The enzyme was first identified in organisms isolated from a patient in Sweden who had previously received medical treatment in India, but it is now recognized as endemic throughout India and Pakistan and has spread worldwide. The gene encoding NDM-1 has been found predominantly in Escherichia coli and Klebsiella pneumoniae. We describe the isolation NDM-1-producing organisms from two patients in Toronto, Ontario. To the best of our knowledge, this is the first report of an organism producing NDM-1 that was locally acquired in Canada. We also discuss the evidence that NDM-1 can affect bacterial species other than E. coli and K. pneumoniae, the limited options for treatment and the difficulty laboratories face in detecting organisms that produce NDM-1.

Dominance of CTX-M group 1 beta-lactamase enzymes in ESBL producing E. coli from outpatient urines in neighboring regions of Austria and Italy.

The importance of extended spectrum ß-lactamases (ESBL) is increasing worldwide. ESBLs of the CTX-M type are on the rise in Europe, not only in the hospital environment but also in outpatients. Therefore we performed a comparative pilot study including ESBL producing Escherichia coli isolated from outpatients suffering from urinary tract infections, 28 from Innsbruck, Austria, and 34 from Bolzano, Italy. Using established PCR methods we detected in nearly 90% of ESBL producing E. coli isolates CTX-M group 1 enzymes and only a few group 2 or group 9 enzymes. bla (TEM), bla (OXA-1) and aminoacyltransferase aac(6')-lb were significantly more frequent in the Austrian region, where also bla (SHV )was found in one isolate. In 2009 the overall prevalence of ESBL in E. coli causing urinary tract infection in outpatient samples was 7.6% in a local laboratory in Innsbruck and 5% in Bolzano. Additionally, we investigated plasmid-mediated qnr genes which can contribute to quinolone resistance, qnrA was found in an AmpC producing E. coli from Innsbruck and qnrS in two ESBL producers from Bolzano. Data confirmed that ESBL-producing E. coli have emerged as important pathogens in urinary tract infections of outpatients in both regions.

Detection of ESBL bacteria from clinical specimens: evaluation of a new selective medium.

Selective screening media for extended-spectrum beta-lactamase (ESBL)-producing bacteria are needed to guide antibiotic therapy and institute appropriate infection control measures. This study evaluates a selective cefpodoxime-incorporated chromogenic agar (CCA) medium for the detection of ESBLs from clinical specimens. The medium was formulated specifically for this study. For all culture-positive urine samples and wound swabs from intensive care unit (ICU) patients, CCA was compared with standard laboratory testing procedures and HPA/BSAC guidance on ESBL detection. The CCA medium was also evaluated for ESBL faecal carriage from patients on ICU and the haematology ward. These patients had no prior evidence of colonisation or infection with ESBL-producing bacteria. All ESBL isolates underwent minimum inhibitory concentration (MIC) testing to cefpodoxime. The Miles and Misra method and the ecometric methods were used to quality control the microbiological performance of the CCA medium, which proved satisfactory. A total of 750 specimens were examined (690 urines, 40 faeces, 20 wound swabs). From urine cultures, 92 suspect colonies were followed up. Eighteen were cefpodoxime-resistant on routine disc testing and all were confirmed subsequently as ESBL-positive. Conventional laboratory methods identified only two urinary ESBLs. Wound cultures revealed two suspect colonies, both of which were ESBL-positive and were also detected by routine methods. Faecal samples produced 10 suspect colonies, six of which were ESBL-positive. All ESBLs had cefpodoxime MICs >10 mg /L (75% were >256 mg/L). Thus, primary conventional culture methods cannot be relied upon to detect suspect ESBL-producing bacteria.

Epidemiología de las BLEE en la comunidad: un problema emergente / Epidemiology of ESBL in the community. An increasing problem

La emergencia de infecciones comunitarias por Escherichia coli productora de betalactamasas de espectro extendido (BLEE) es un fenómeno nuevo y generalizado, coincidente con la irrupción de enzimas CTX-M, que en nuestro país comienza a partir del año 2000. Las enzimas que se observan con más frecuencia pertenecen a la familia CTX-M y en segundo lugar encontramos SHV-12. Estos aislados están implicados principalmente en infecciones urinarias y se asocian a factores de riesgo como el uso de sonda urinaria y de antibióticos previamente. Su epidemiología es compleja ya que se han descrito clones epidémicos que afectaban a pacientes extra e intrahospitalarios, así como la detección de aislados no agrupados clonalmente y la diseminación horizontal de un grupo determinado de enzimas mediante elementos móviles. Existen portadores fecales en la comunidad, pero se desconoce actualmente el reservorio y las formas de transmisión, lo que supone una limitación para establecer medidas de control eficaces

The emergence of community infections due to ESBL-producing Escherichia coli is a new and widespread phenomenon, coinciding with the irruption of CTX-M enzymes, which in Spain began to occur in 2000. The most frequently observed enzymes belong to the CTX-M family, followed by the SHV-12 family. These isolates are implicated mainly in urinary infections and are associated with risk factors such as the use of urinary catheters and prior antibiotic use. The epidemiology of these microorganisms is complex since epidemic clones have been described, which affect patients both in the extra- and intrahospital setting, as well as detection of isolates in different clonal groups. Furthermore, horizontal dissemination from a specific group of enzymes through mobile elements has also been described. Fecal carriers exist in the community. However, the reservoir and forms of transmission are currently unknown, hampering the instauration of effective control measures