Antimicrobial-resistant enterobacteria in surface waters with fecal contamination from urban and rural communities

Abstract INTRODUCTION: Inadequate wastewater treatment and fecal contamination have a strong environmental impact on antimicrobial resistance (AMR). This study evaluated the profile of AMR enterobacteria and fecal contamination from four surface waters: Jiquiriça-Brejões River and Cabrito, Tororó, and Abaeté Lagoons. METHODS: We analyzed AMR β-lactamase genes using the polymerase chain reaction method and fecal contamination using Coliscan®. RESULTS: We found high levels of fecal contamination, β-lactamase producers, and AMR genes (blaOXA-48, blaSPM, and blaVIM) in all waterbodies. CONCLUSIONS: Poor sanitation evidenced by fecal contamination and human activities around these surface waters contributed to the distribution and increase in AMR enterobacteria.

High prevalence of CTX-M-1 group in ESBL-producing enterobacteriaceae infection in intensive care units in southern Chile

ABSTRACT Enterobacteria-producing extended-spectrum β-lactamases (ESBL) play an important role in healthcare infections, increasing hospitalization time, morbidity and mortality rates. Among several ESBLs that emerge from these pathogens, CTX-M-type enzymes had the most successful global spread in different epidemiological settings. Latin America presents high prevalence of CTX-M-2 in ESBL-producing enterobacterial infections with local emergence of the CTX-M-1 group. However, this high prevalence of the CTX-M-1 group has not yet been reported in Chile. The aim of this study was to identify ESBLs among enterobacteria isolated from clinical samples of critically ill patients from southern Chile. One-hundred thirty seven ESBL-producing bacteria were isolated from outpatients from all critical patient units from Hernán Henríquez Aravena Hospital. Phenotype characterization was performed by antibiogram, screening of ESBL, and determination of minimum inhibitory concentration (MIC). PCR was used for genetic confirmation of resistance. Molecular typing was performed by ERIC-PCR. ESBL-producing isolates were identified as Klebsiella pneumoniae (n = 115), Escherichia coli (n = 18), Proteus mirabilis (n = 3), and Enterobacter cloacae (n = 1), presenting multidrug resistance profiles. PCR amplification showed that the strains were positive for blaSHV (n = 111/81%), blaCTX-M-1 (n = 116/84.7%), blaTEM (n = 100/73%), blaCTX-M-2 (n = 28/20.4%), blaCTX-M-9 (0.7%), blaPER-1 (0.7%), and blaGES-10 (0.7%). The multiple production of ESBL was observed in 93% of isolates, suggesting high genetic mobility independent of the clonal relationship. The high frequency of the CTX-M-1 group and a high rate of ESBL co-production are changing the epidemiology of the ESBL profile in Chilean intensive care units. This epidemiology is a constant and increasing challenge, not only in Chile, but worldwide.

An Epidemiologic Study on Hosts and Pathogens of Urinary Tract Infection in Urban Children of Korea (2012–2017)

PURPOSE: We aimed to determine characteristics of host, causative organisms, and antibiotic susceptibility of bacteria in pediatric patients with UTI living in metropolitan area of Korea. METHODS: Retrospective investigation was done for the causative organisms of UTI in 683 pediatric cases treated at Ajou University Hospital from 2012 to 2017. Patients were classified into Escherichia coli and non-E.coli group, where E.coli group was subdivided into ESBL(+) and ESBL(−) groups based on whether the bacteria could produce extended spectrum beta-lactamase (ESBL). Antibiotic susceptibility of the causative organism was also determined. RESULTS: A total of 683 UTIs occurred in 550 patients, of which 463 (67.8%) were first-time infection and 87 (32.2%) were recurrent ones (2–7 recurrences, 2.52 average), and 64.9% were male and 35.1% were female. The most common causative organism was E.coli (77.2%) and ESBL(+) E.coli was found in 126 cases. The susceptibility of E.coli to 3rd or 4th generation cephalosporin was relatively higher than that to ampicillin or amoxicillin/clavulanic acid. ESBL(+) E.coli showed higher resistance rate to 3rd or 4th generation cephalosporin than ESBL(−) E.coli . CONCLUSION: New treatment guideline should be considered due to the incidence of ESBL(+) E.coli increased up to one quarter of UTI cases.

Analysis of gene and drug resistance of ESBL producing bacteria in neonatal feces / 临床儿科杂志

Objectives To explore the route of ESBL producing bacteria in neonatal faeces, and to investigate the gene and drug resistance of ESBL producing bacteria in intestinal tract of neonates. Methods Fecal samples of healthy newborns and their mothers were collected, and bacterial cultures were carried out using selective ESBL medium. The positive strains were identified by Time-of-flight mass spectrometry. ESBL genotyping and resistance gene detection were performed by whole genome sequencing technique. Results In 146 neonatal fecal specimens, the positive rate of ESBL producing bacteria was 8.90％,and the positive rate in the first time stool was 3.23％. Seventy-two hours after birth, the positive rate of fecal ESBL producing bacteria was 13.10％. Among the 13 ESBL producing strains, there were 9 strains of CTX type, 3 strains of TEM type and 1 strain of SHV type. Nine strains of CTX include five types such as CTX-M-24, CTX-M-18, CTX-M-27, CTX-M-42 and CTX-M-15. The positive rate of ESBL producing bacteria was 21.6％ in 167 mothers' fecal specimens. The ESBL genotype included 24 strains of CTX type, 6 strains of TEM type, 4 strains of SHV type and 2 strains of QnrS type. Twenty-four strains of CTX include CTX-M-24, CTX-M-14, CTX-M-18, CTX-M-27, CTX-M-42 and CTX-M-15. There were 2 or 3 ESBL genotypes in 12 maternal and neonatal specimens. It was detected to have 6 types of resistance gene such as aadA5, strA, strB, sul1, sul2 and dfrA17 in 49 strains of ESBL producing bacteria in maternal and neonatal strains. Resistance genes were exactly the same in the neonates as in mothers who were detected to have ESBL producing bacteria. A variety of resistance genes were detected in feces in 7 neonates and 23 mothers. Conclusions The neonates in hospital may be detected to have ESBL produing bacteria in the intestinal tract at the same time as their mothers or separately. However, there are many ways for neonates to have ESBL producing bacteria in intestinal tract. There are many genotypes and resistance genes of ESBL producing bacteria.

In vitro susceptibility pattern of Tigecycline against MRSA, ESBL producing Escherichia coli, Klebsiella species and Acinetobacter isolates in a rural tertiary care hospital.

Background: Tigecycline is the first commercially available glycycline, derivatives of the tetracycline antibiotics, having enhanced activity against various pathogens. In vitro activity has been demonstrated against multi drug resistant Gram positive and Gram negative pathogens like MRSA, ESBL producing Esch.coli and Klebsiella spp. and Acinetobacter Objective: To determine Tigecycline in vitro susceptibility pattern in MRSA, ESBL producing Esch.coli and Klebsiella spp. and Acinetobacter spp. Material and Methods: Investigations were carried out from August 2012-January 2014 to detect MRSA,ESBL producing Escherichia coli and Klebsiella spp. as well as Acinetobacter spp. by using a standard protocols and Tigecycline in-vitro susceptibility testing was done by Kirby Bauer Disc diffusion method and it’s MIC value against resistant isolates was evaluated.Statistical analysis was done by Fishers extract method. Result: Out of 107 Staphylococcus aureus isolates 52(48.59%) were MRSA, none of them showed resistance to Tigecycline. Out of 82 Esch.coli isolates 14 (i.e 17.07%) were ESBL producers, none of them showed resistance to Tigecycline.Out of 67 Klebsiella isolates 21 (i.e 31.34%) were ESBL producers out of which only 1 (i.e 4.76%) was resistant to Tigecycline.Out of 19 Acinetobacter spp.isolated 3 (i.e 15.78%) were resistant to Tigecycline. The MIC range for ESBL producing Eschcoli, Klebsiella spp., MRSA and acinetobacter spp were 0.14-0.45 μg/ml,0.25-2.4 μg/ml,0.12-0.26 μg/ml, 1-3.2 μg/ml respectively. Conclusion: The results of the study confirm the excellent in vitro activity of Tigecycline against Gram positive and Gram negative multidrug resistant pathogens.

Molecular Epidemiologic Analysis of Community-Onset Extended Spectrum Beta-Lactamase (ESBL) Producing Escherichia coli Using Infrequent-Restriction-Site Polymerase Chain Reaction (IRS-PCR) with Comparison by Pulsed-Field Gel Electrophoresis (PFGE)

BACKGROUND: We evaluated the ability of infrequent restriction site-polymerase chain reaction (IRS-PCR) to perform molecular epidemiologic analysis of Community-Onset Extended Spectrum Beta-Lactamase (ESBL) producing Escherichia coli, and also assessed the use of PFGE as an alternative method. MATERIALS AND METHODS: IRS-PCR assay was performed using combinations of adaptors for XbaI and HhaI restriction sites on clinical isolates of E. coli (n=51). We compared the discriminatory power, quality and efficiency of IRS-PCR to PFGE. RESULTS: In E. coli, PFGE discriminated 39 (76.4%) and IRS-PCR discerned 41 (80.3%) of the total 51 strains. It took much less time to complete IRS-PCR (one day) than PFGE (at least 4 days). CONCLUSIONS: IRS-PCR is a more sensitive and rapid alternative to PFGE for molecular epidemiologic analysis of E. coli.

Prevalence and risk factors for colonisation with extended spectrum β-lactamase producing enterobacteriacae vis-à-vis usage of antimicrobials.

Purpose: A point prevalence study was carried out in a teaching hospital in Assam to determine the prevalence, sensitivity profile and risk factors for acquisition of extended spectrum β-lactamase (ESBL) producing enterobacteriacae vis-ΰ-vis amount and pattern of antibiotic use. Materials and Methods: ESBL was detected by double disc synergy method. Defined daily dose and bed-days were calculated. Result: Colonisation rate of ESBL producing enterobacteriacae ranged from 14% (n=73) in medicine to the highest 41% (n=29) in orthopaedic with an intermediate 23% (n=80) in surgery. Presence of ESBL was found to be strongly associated with resistance to specific classes of antimicrobials. Exposure to cefotaxime and gentamicin, and surgery were risk factors for acquiring ESBL producing enterobacteriacae. Non-ESBL producing community isolates were found to be considerably more sensitive to different antibiotics with no resistance detected to trimethoprim, co-trimoxazole, ciprofloxacin and aminoglycosides. Conclusion: The study confirms the role of certain 'high risk' antimicrobials in acquisition of ESBL producing Enterobacteriaceae and shows that periodic cohort studies could be an effective strategy in surveillance of antimicrobial resistance in hospitals of resource poor countries to inform antibiotic policy and treatment guidelines.

In Vitro Susceptibility of piperacillin/tazobactam Against extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae

Minimal inhibitory concentrations (MIC) of piperacillin/tazobactam were determined on 20 clinical isolates of extended-spectrum beta-lactamase (ESBL)-producing E. coli and 30 isolates of ESBL- producing Klebsiella pneumoniae. MIC50 and MIC90 for ESBL-producing E. coli were 8/4 microg/ml and 256/4 microg/mL, respectively. MIC50 and MIC90 for ESBL-producing K. pneumoniae were 8/4 microg/mL and > 512/4 microg/mL, respectively. The susceptibilities of ESBL-producing E. coli and K. pneumoniae to piperacillin/tazobactam were 80% and 60%, respectively. Of 20 ESBL-producing E. coli strains, 11 (55%) were TEM-and CTX-M-positive, and SHV-negative. Of 30 ESBL-producing K. pneumoniae strains, ten (33%) were PCR positive for SHV and negative for TEM and CTX-M.

In Vitro Susceptibility of piperacillin/tazobactam Against extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae

Minimal inhibitory concentrations (MIC) of piperacillin/tazobactam were determined on 20 clinical isolates of extended-spectrum beta-lactamase (ESBL)-producing E. coli and 30 isolates of ESBL- producing Klebsiella pneumoniae. MIC50 and MIC90 for ESBL-producing E. coli were 8/4 microg/ml and 256/4 microg/mL, respectively. MIC50 and MIC90 for ESBL-producing K. pneumoniae were 8/4 microg/mL and > 512/4 microg/mL, respectively. The susceptibilities of ESBL-producing E. coli and K. pneumoniae to piperacillin/tazobactam were 80% and 60%, respectively. Of 20 ESBL-producing E. coli strains, 11 (55%) were TEM-and CTX-M-positive, and SHV-negative. Of 30 ESBL-producing K. pneumoniae strains, ten (33%) were PCR positive for SHV and negative for TEM and CTX-M.

In vitro activity of ceftobiprole against hospital-acquired bacteria commonly causing infections in hospitalized patients at Siriraj Hospital.

Objective: To determine the in vitro activity of ceftobiprole against resistant bacteria commonly causing infections in hospitalized patients at Siriraj Hospital. Methods: The studied organisms were MRSA (32 isolates), Enterococcus sp. (30 isolates), ESBL-producing E.coli (20 isolates), ESBL-producing K.pneumoniae (20 isolates), MDR P.aeruginosa (30 isolates) and MDR A.baumannii (30 isolates). The susceptibility of ceftobiprole was determined by the disk diffusion test for all 162 isolates and the MIC was determined by the E-test method for 5 isolates of each organism. Results: All isolates of MRSA and 77% of Enterococcus sp. isolates were susceptible to ceftobiprole. All isolates of ESBL-producing E.coli and MDR A.baumannii were not susceptible to ceftobiprole. Only 10% to 20% of ESBL-producing K.pneumoniae and P.aeruginosa were susceptible to ceftobiprole. The MICs of ceftobiprole against all tested organisms were correlated with the inhibition zone diameters. Conclusion: Ceftobiprole is very active against MRSA and is moderately active against Enterococcus sp. Ceftobiprole is considered inactive or less active against ESBL-producing gram negatives, MDR P.aeruginosa and MDR A.baumannii.

Clinical Characteristics of Extended-spectrum beta-lactamase Producing Shigella sonnei Infection Outbreaked in Chungju Area / 대한진단검사의학회지

BACKGROUND: An outbreak of extended-spectrum-lactamase (ESBL)-producing Shigella sonnei enteritis, especially in pediatric populations, was unprecedented not only in Korea, but also throughout the world in the past. This study was intended to devise a management guideline for shigellosis caused by an ESBL-producing strain based on analysis of the clinical manifestations and response to therapy. METHODS: We examined 24 strains of S. sonnei isolated from stool cultures of patients with acute enteritis, between November 2004 and February 2005, for antimicrobial susceptibility and ESBL production, and we also performed DNA sequencing with PCR for the typing of ESBL genes. In addition, we retrospectively analyzed the clinical characteristics, laboratory results, and therapeutic responses to antibiotics of the 103 patients who grew S. sonnei on stool cultures. RESULTS: All 24 isolates showed a very similar antibiotic sensitivity pattern and were ESBL gene type of CTX-M-14. The most frequent clinical symptom in the 103 patients was a fever, followed by diarrhea, abdominal pain, headache, vomiting, and nausea. Leukocytosis and CRP were positive in 53.4% and 78.6% of the patients, respectively. On stool direct smears, 11.7% showed more than 50 WBCs per HPF and 71% were positive on stool occult blood. Microbiological eradication rates were as follows: azithromycin and ciprofloxacin, 100%; imipenem-cilastatin, 68.8%; ampicillin-sulbactam, 42.9%; amoxicillin-clavulanic acid, 20%; ceftizoxime, 12.5%; cefdinir, 6.9%; and ceftriaxone and trimethoprim-sulfamethoxazole, 0%. CONCLUSIONS: We presumed that, given its cost-effectiveness and safety, azithromycin can be an attractive option for the treatment of ESBL-producing S. sonnei enteritis in pediatric populations. Although ciprofloxacin is another cost-effective agent, its use in pediatric populations is not recommended.