Enterobacteriaceae Infections Research Articles

Emerging Carbapenem-Resistant Enterobacteriaceae Infection, Its Epidemiology and Novel Treatment Options: A Review.

Infections due to multidrug-resistant Enterobacteriaceae have become major international public health problem due to the inadequate treatment options and the historically lagged pace of development of novel antimicrobial drugs. Inappropriate antimicrobial use in humans and animals coupled with increased global connectivity aided to the transmission of drug-resistant Enterobacteriaceae infections. Carbapenems are the medications of choice for extended-spectrum beta-lactamase and AmpC producers, but alternatives are currently needed because carbapenem resistance is increasing globally. This review pointed to discuss emerging drug-resistant Enterobacteriaceae, its epidemiology and novel treatment options for infections, which date back from 2010 to 2019 by searching Google Scholar, PubMed, PMC, Hinari and other different websites. The occurrence of carbapenem-resistant Enterobacteriaceae is reported worldwide with great regional variability. The rise of carbapenem-resistant Enterobacteriaceae poses a threat to all nations. Enzyme synthesis, efflux pumps, and porin mutations are the main methods by which Enterobacteriaceae acquire resistance to carbapenems. The major resistance mechanism among these is enzyme synthesis. Most carbapenem resistance is caused by three enzyme groups: Klebsiella pneumoniae carbapenemase (Ambler class A), metallo-ß-lactamases (Ambler class B), and oxacillinase-48 (Ambler class D). Ceftazidime–avibactam, which was newly licensed for carbapenemase producers, is the most common treatment option for infections. Meropenem–vaborbactam, imipenem–relebactam, plazomicin, cefiderocol, eravacycline, and aztreonam–avibactam are recently reported to be active against carbapenem-resistant Enterobacteriaceae; and are also in ongoing trials for different populations and combinations with other antibacterial agents. Overall, treatment must be tailored to the patient’s susceptibility profile, type and degree of infection, and personal characteristics.

Molecular Surveillance and Assessment of Ceftolozane/Tazobactam Resistance with Common β-Lactam Antibiotics and β-Lactamase Genes

Ceftolozane/tazobactam (c/t) is a potent β-lactam antibiotic which combines the fifth generation cephalosporin ceftolozane and tazobactam, a β-lactamase inhibitor. The c/t combination therapy was approved in 2014 for the treatment of multidrug resistant (MDR) Enterobacteriaceae, especially intra-abdominal and urinary tract infections. The aim of this study is to assess c/t activity and to examine the association of c/t resistance with four common β-lactamase resistance genes found in clinical Enterobacteriaceae isolates collected from mainly urinary tract infections in an agricultural region in California (USA) between 2013-2020. We tested 993 Extended Spectrum β-lactamases (ESBL) producing Enterobacteriaceae isolates (885 E. coli, 94 K. pneumoniae, 14 other) for c/t susceptibility by Kirby-Bauer disk diffusion and screened using PCR for four common resistance genes with β-lactamase activity(blaTEM, blaOXA, blaSHV, and blaCTX-M) for 855 of the isolates. We also investigated co-resistance of c/t and nine other β-lactam antibiotics. We found that most isolates were susceptible to c/t (58.3%), while 38.5% showed intermediate resistance, and 3.2% were resistant. We also found that K. pneumoniae isolates were more resistant to c/t than E. coli isolates, and that c/t may be a good alternative to carbapenems, in that that some carbapenem resistant isolates were susceptible to c/t. Genotypic analysis showed blaSHV and blaCTX-M are independently associated with elevated c/t resistance. Although c/t demonstrated strong activity against Enterobacteriaceae, the high percentage of isolates with intermediate susceptibility emphasizes the need for close monitoring and continued surveillance for c/t resistance among ESBLs

Genomic Characterization of ESBL- and Carbapenemase-Positive Enterobacteriaceae Co-harboring mcr-9 in Japan.

Worldwide spread of Enterobacteriaceae resistant to colistin, a polypeptide antibacterial drug for last-resort treatment of carbapenemase-producing Enterobacteriaceae (CPE) infections, is concerning. This study aimed to elucidate colistin MICs and molecular characteristics of mcr-1 to mcr-9 of ESBL-producing Escherichia coli (ESBL-Ec) and CPE in Japan and clarify the genomic structure of strains harboring mcr genes (especially mcr-9). This study included 168 ESBL-Ec and 126 CPE strains isolated at Japanese medical facilities. Colistin susceptibility testing and multiplex PCR targeting mcr-1 to mcr-9 were performed for all strains with S1-nuclease pulsed-field gel electrophoresis, Southern blot hybridization, and whole-genome sequencing (WGS) with hybrid assembly performed for mcr gene-carrying strains. Two CPE strains showed a MIC ≥ 4 μg/ml in colistin susceptibility testing, with no known resistance mechanism detected. However, PCR conducted on all target strains detected three mcr-9-carrying strains showing colistin susceptibility. The blaCTX–M–62-positive E. coli THUN648 strain simultaneously carried blaCTX–M–62 and mcr-9 on a 275-kbp plasmid. Besides, blaIMP–6 + blaCTX–M–2-positive Klebsiella pneumoniae THUN262 and blaGES–24-positive Enterobacter kobei THUN627 had mcr-9 encoded on the chromosome. Only THUN627 encoded qseB/C, which is suggested to be a regulatory gene for mcr-9, downstream of mcr-9. However, this strain showed no increased expression of these genes in mRNA quantitative analysis under colistin exposure. Colistin MICs of ESBL-Ec and CPE in Japan were all below 2 μg/ml, which is below the epidemiological cutoff (ECOFF) value (https://eucast.org/) or clinical breakpoint (CB) (CLSI M100-S30) reported for colistin, indicating neither “microbiological” nor “clinical” resistance. Several colistin-susceptible Enterobacteriaceae carrying silent mcr-9 encoded on plasmids and chromosomes have already spread worldwide along with other antimicrobial resistance genes. However, the mechanism of colistin resistance by mcr-9 remains unclear.

Community-onset ESBL– producing enterobacteriaceae urinary tract infection in pediatric patients: Retrospective case control study

Background: Urinary tract infection (UTI) is a common childhood disease with a prevalence of 7.8% that can lead to serious complications including renal scarring.Approximately 80% of UTIs in children are caused by Escherichia coli that are unfortunately accompanied by an increased prevalence of extended-spectrum beta-lactamases (ESBL) - producing strains. This study tries to determine the incidence of ESBL-producing Enterobacteriaceae (PE) UTIs among the pediatric population in Qatar, and predict the relation between multiple antibiotics exposure, antibiotic prophylaxis, recurrent UTIs, prior hospitalizations, prior urinary tract abnormalities as risk factors, and the development of ESBL-PE UTI in the same population. Methods: This is a retrospective case control and cross-sectional study conducted over a period of one year from January 2018 to January 2019. The inclusion criteria were infants and children from 0 month to 14 years old diagnosed with community-onset of urinary tract infection however, exclusion criteria were immunocompromised or cancer patients. Case group was defined as patients who developed ESBL-PE UTI (n = 135), while the control group were patients who developed sensitive Enterobacteriaceae UTI (n = 219). Results: 406 patients were included, 33% of them had ESBL-PE UTI and 51 were excluded (infection caused by another organism). Regarding antibiotics exposure during the preceding 6 months, 28% of the case group patients were prescribed multiple courses of antibiotics versus 10% in the control group. 21% within the case group patients received antibiotic prophylaxis versus 6% in the control group. Furthermore, 21% of case group patients were diagnosed with urinary tract anomalies versus 4.5% in the control group, however no significant statistical difference regarding UTI recurrence was found (p>0.05). 17% of case group patients were hospitalized previously versus 7% in the control group. Conclusion: The study found that ESBL-PE UTI incidence among pediatric patients was high. Repeated exposure to antibiotics courses, antibiotic prophylaxis, previous hospitalization, and prior UT anomalies may have an impact on this resistance rate.

Paediatric Enterobacteriaceae infections in hospitalised children in Durban, KwaZulu-Natal

Background: Community-acquired Gram-negative Enterobacteriaceae infections in malnourished and HIV-infected hospitalised children are not well documented and are of concern because of increasing antibiotic resistance and limited available treatment options. This study describes the clinical characteristics and outcomes of hospitalised children with positive Enterobacteriaceae cultures.Method: A retrospective chart review of children with Gram-negative Enterobacteriaceae infections was performed in King Edward VIII Hospital, a referral hospital in Durban, KwaZulu-Natal. Standard descriptive and analytical statistics, including regression analysis, were performed to determine the clinical characteristics associated with Enterobacteriaceae infections in children hospitalised in the study period.Results: Of all hospitalised children in the study period, 207 (3.5%) had positive cultures for Enterobacteriaceae isolates, with Escherichia coli 109 (44.5%) and Klebsiella spp. 59 (24.1%) making up most of the infections. Urine (126; 58%) followed by stool (34; 14.8%) and blood (35; 14.0%) were the commonest samples that yielded positive cultures. Diarrhoeal hospitalisations especially posed a higher risk for Enterobacteriaceae infections. Severe acutely malnourished and HIV-infected children were at higher risk. These comorbidities were independently associated with an increased risk of Enterobacteriaceae infection. Prolonged hospitalisation and increased risk of death were also associated with Enterobacteriaceae infection.Conclusion: Enterobacteriaceae infections were common in hospitalised children and posed an increased risk, especially in malnourished and HIV-infected children. Further studies investigating the relationships between diarrhoea, urinary tract infections and Enterobacteriaceae infections are needed.

Clinical Outcome of Patients on Ceftazidime–Avibactam and Combination Therapy in Carbapenem-resistant Enterobacteriaceae

IntroductionCarbapenem-resistant Enterobacteriaceae (CRE) infections have a major effect on mortality as well as healthcare cost. Intensive care units (ICUs) in India, the epicenters for multidrug-resistant organisms, are facing a “postantibiotic era” because of very limited treatment options. A latest beta-lactam/beta-lactamase inhibitor ceftazidime–avibactam (CZA) new has a broad-spectrum antibacterial activity. CZA inhibits class-A and class-C beta-lactamases (as well Klebsiella pneumoniae carbapenemase (KPC)), along with some class-D carbapenems such as OXA-48-like enzymes that are seen in Enterobacteriaceae has recently become available. The current study aimed to assess and present the clinical response and patient outcome with infections due to CRE when treated with CZA alone or in combination with other drugs.Materials and methodsThis retrospective study reviews the experience recorded and analyzed at two tertiary care centers including only adult patients with CRE infection who had received CZA alone or in combination with other antibiotics over a period between February 2019 and January 2020.ResultsIn the period from February 2019 to January 2020, 119 culture-confirmed CRE isolates were tested for Xpert Carba-R. The predominant genetic mechanism was a combination of NDM+OXA-48 in 45/119 (37.81%). Total 40/57 patients received CZA+aztreonam alone or in combination with other drugs with an overall cure rate of 77.5% while the rest 17 received CZA alone in combination with the cure rate of 82.35%. 41/57 (71.92%) patients were in ICU.ConclusionWith overall mortality of 21%, these data suggest that CZA is a viable option for patients with CRE infections. To our knowledge, this is the first Indian study reporting CZA data in CRE infections.How to cite this articleNagvekar V, Shah A, Unadkat VP, Chavan A, Kohli R, Hodgar S, et al. Clinical Outcome of Patients on Ceftazidime–Avibactam and Combination Therapy in Carbapenem-resistant Enterobacteriaceae. Indian J Crit Care Med 2021;25(7):780–784.

Bacterial characteristics of carbapenem-resistant Enterobacteriaceae (CRE) colonized strains and their correlation with subsequent infection

BackgroundSearching the risk factors for carbapenem-resistant Enterobacteriaceae (CRE) infection is important in clinical practice. In the present study, we aim to investigate bacterial characteristics of colonizing strains and their correlation with subsequent CRE infection.MethodsBetween May 2018 and January 2019, patients hospitalized in the department of haematology and intensive care unit (ICU) were screened for CRE by rectal swabs and monitored for the outcome of infection. We identified the species and carbapenemase-encoding genes of colonizing strains and performed antimicrobial susceptibility tests and multilocus sequence typing (MLST). Risk factors for subsequent CRE infections were ascertained by univariate and multivariable analysis.ResultsWe collected a total of 219 colonizing strains from 153 patients. Klebsiella pneumoniae was the most abundant species, and MLST analysis showed rich diversity. K. pneumoniae carbapenemase (KPC) was predominant in the infection group (72.4%). In the non-infection group, 35.4% of strains were non-carbapenemase-producing CRE (NCP-CRE), and New Delhi metallo-β-lactamase (NDM) was predominant (42.2%). The rate of high-level carbapenem resistance (minimum inhibitory concentration [MIC] ≥ 64 mg/L for meropenem and ertapenem, ≥ 32 mg/L for imipenem) was remarkably higher in the infection group than in the non-infection group (P < 0.001). Univariate analysis showed that K. pneumoniae, high-level carbapenem resistance, CP-CRE and KPC-CRE were infection risk factors after CRE colonization. On multivariable analysis with different carbapenemase dichotomizations, KPC-CRE (adjusted odds ratio [aOR], 4.507; 95% confidence interval [CI], 1.339–15.171; P = 0.015) or imipenem MIC ≥ 32 mg/L (aOR, 9.515; 95% CI, 1.617–55.977; P = 0.013) were respectively identified as independent risk factors for subsequent infection.ConclusionsPatients colonized with KPC-CRE or strains with an imipenem MIC ≥ 32 mg/L were at particularly high risk of subsequent CRE infections during their hospital stay.

Impact of COVID-19 on Antimicrobial Use and Resistance in an Urban Safety-Net Community Hospital

Background: The disease caused by SARS-CoV-2, COVID-19, has caused a pandemic leading to strained healthcare systems worldwide and an unprecedented public health crisis. Lower respiratory tract infections (LRTIs) and hypoxia caused by COVID-19 has led to an increase in hospitalizations. We sought to define the impact of COVID-19 on antimicrobial use and antimicrobial resistance (AMR) in an urban safety-net community hospital. Methods: Retrospective review of antimicrobial use and AMR in a 151-bed urban community hospital. Antimicrobial use was calculated in days of therapy per 1,000 patient days (DOT/1,000 PD) for ceftriaxone, piperacillin-tazobactam and meropenem during 2019 and 2020. Ceftriaxone, piperacillin-tazobactam and meropenem were reviewed for calendar year 2019 and 2020. AMR was assessed by comparing the carbapenem resistant Enterobacteriaceae (CRE) infection incidence rate per 1,000 patient days between 2019 and 2020. Results: The average quarterly DOT/1,000 PD increased from 359.5 in 2019 to 394.25 in 2020, with the highest increase in the second and fourth quarters of 2020, which temporarily correspond to the first and second waves of COVID-19. Ceftriaxone and meropenem use increased during the first and second waves of COVID-19. Piperacillin-tazobactam use increased during the first wave and declined thereafter (Figure 1). Rates of CRE increased from a quarterly average of 0.57 to 0.68 (Figure 2). Conclusions: Antimicrobial pressure increased during the first and second waves of COVID-19. Ceftriaxone was the most commonly used antimicrobial, reflecting internal guidelines and ASP interventions. CRE rates increased during COVID-19. This finding may be due to an overall increase in antimicrobial pressure in the community and in critically ill patients. Antibiotics are a precious resource, and antimicrobial stewardship remains important during the COVID-19 pandemic. Appropriate use of antimicrobials is critical to preventing AMR.Funding: NoDisclosures: None

Choosing Optimal Antibiotics for the Treatment of Patients Infected With Enterobacteriaceae: A Network Meta-analysis and Cost-Effectiveness Analysis.

Overuse of carbapenems has led to the increasing carbapenem-resistant Enterobacteriaceae. It is still unknown whether other antibiotics [especially novel β-lactam/β-lactamase inhibitor combinations (BL/BLIs)] are better than carbapenems in the treatment of Enterobacteriaceae. A systematic literature search was performed to identify randomized controlled trials (RCTs) assessing the efficacy and safety of any antibiotics on Enterobacteriaceae infections. We carried out a traditional paired meta-analysis to compare ceftazidime/avibactam to comparators. Network meta-analysis (NMA) was conducted to integrate direct and indirect evidence of all interventions. Moreover, cost-effectiveness analysis using a combined decision analytical Markov model was completed for the treatment of patients with complex urinary tract infection (cUTI). A total of 25 relevant RCTs were identified, comprising 15 different interventions. Ceftazidime/avibactam exhibited comparable efficacy and safety with comparators (carbapenems) in the paired meta-analysis. In the NMA, the surface under the cumulative ranking curve probabilities showed that in terms of efficacy, the interventions with the highest-ranking were meropenem/vaborbactam, meropenem, imipenem/cilastatin, ceftriaxone, ceftazidime/avibactam, and ceftolozane/tazobactam [but no significant difference between any two antibiotics (p > 0.05)]. Regarding safety, ceftazidime/avibactam had a higher incidence of adverse events than that of piperacillin/tazobactam (relative risk = 0.74, 95% confidence interval = 0.59–0.94). Based on drug and hospitalization costs in China, the incremental cost-effectiveness ratio per quality-adjusted life-year gained in the patients with cUTI for meropenem, ceftazidime/avibactam, and ceftolozane/tazobactam compared to imipenem/cilastatin were US$579, US$24569, and US$29040, respectively. The role of these BL/BLIs to serve as alternatives to carbapenems requires large-scale and high-quality studies to validate.

Dissemination of IncFII plasmids carrying fosA3 and blaCTX-M-55 in clinical isolates of Salmonella enteritidis.

Multidrug-resistant Salmonella Enteritidis (S. Enteritidis) isolates have become a significant threat to public health, and fosfomycin has been proposed as one of the therapeutic antibiotics for serious infections by resistant pathogens. In this study, a total of 501 clinical S. Enteritidis isolates were screened and 14 (2.8%) isolates exhibited resistance to fosfomycin (MIC≥1,024μg/mL) as well as ceftriaxone (MIC≥128μg/mL). The fosA3 gene was identified in these 14 isolates. The fosA3 gene that co-transferred with blaCTX-M-55 was observed on the IncFII plasmids with sizes of~78 (n=7) or~111 (n=2) kbp in 9 transconjugants. The fosA3-bearing plasmid p12367A is 111,764bp in length and possessed a typical IncFII backbone. A 7.6-kbp multidrug resistance region (MRR) was identified in p12367A, which was comprised of fosA3 and blaCTX-M-55 genes interspersed with ΔISEcp1 and three copies of IS26. Two typical antibiotic resistance determinants (IS26-orf3-orf2-orf1-fosA3-IS26 and IS26-orf477-blaCTX-M-55 -ΔISEcp1-IS26) shared one IS26 in the MRR. The genetic arrangement of the MRR may have resulted from the stepwise integration of IS26 mobile elements via homologous recombination. Horizontal transfer of IncFII plasmids might contribute to the dissemination of fosA3 and blaCTX-M-55 resistance genes in S. Enteritidis interspecies. These findings underline further challenges for the prevention and treatment of Enterobacteriaceae infections posed by epidemic IncFII plasmids bearing fosA3-blaCTX-M-55 .

Improving clinical outcomes via responsible antimicrobial use in horses

SummaryThe growing problem of antimicrobial resistance affects veterinarians on a daily basis. Antimicrobial stewardship and responsible prescribing are essential for a future with effective antimicrobials, as it is unlikely that new antimicrobials will become available for use in horses in the near future. Extended‐spectrum β‐lactamase (ESBL) producing Enterobacteriaceae, methicillin‐resistant Staphylococcus aureus (MRSA) and Salmonella spp. are pathogens of significant concern but there are also other opportunistic pathogens such as Pseudomonas spp., α‐haemolytic Streptococcus spp., Enterococcus spp. and Acinetobacter spp. which, due to their high intrinsic resistance, have limited treatment options in adult horses. It is essential that highest priority critically important antimicrobials such as ceftiofur, enrofloxacin, rifampicin and polymyxin B are used prudently in horses and ideally based on culture and antimicrobial susceptibility testing (AST). For example, the use of polymyxin B at a low anti‐endotoxic dose rather than at a higher antimicrobial dose in horses for the treatment of systemic inflammatory response syndrome is a potential driver for resistance to colistin (polymyxin E), an antimicrobial used as a last resort in the treatment of multidrug resistant (MDR) Enterobacteriaceae infections in humans. Serum procalcitonin levels are used in humans to distinguish noninfectious inflammatory conditions from inflammation caused by bacteria and other infectious agents and are also used to guide cessation of antimicrobial treatment. Although no such studies have been performed in horses, this or other markers may prove to be helpful in guiding antimicrobial treatment decisions in the future. Optimising sampling techniques and good communication with the microbiology laboratory are essential for generating the accurate culture and AST results that underpin appropriate antimicrobial use. Additionally, there is clearly a need for national and international harmonisation of laboratory methods in order to improve the reliability and consistency of results reported by different laboratories.

Temocillin versus carbapenems for urinary tract infection due to ESBL-producing Enterobacteriaceae: a multicenter matched case-control study

ObjectivesTo compare the efficacy of temocillin with carbapenems for extended spectrum β-lactamase (ESBL)-producing Enterobacteriaceae urinary tract infections (ESBL-E UTI). MethodsA multicenter retrospective case-control study of adults with ESBL-E UTI was conducted between January 2015 and October 2019. Cases received temocillin ≥ 50% of the effective antibiotic therapy duration and controls exclusively received carbapenem; they were statistically matched (1:1 ratio) on 6-month period, sex and age. The clinical cure at the end of antibiotic therapy was analysed using conditional logistic regression. ResultsSeventy-two temocillin cases were matched to 72 carbapenem controls. Most (67%) were male, median age was 69.4 years, 81 (56%) were immunocompromised, including 44 (31%) solid organ transplant recipients. There was no difference between cases and controls for baseline characteristics and microorganisms involved: Klebsiella pneumoniae in 59 (41%), Escherichia coli in 57 (40%), and Enterobacter spp. in 24 (17%). The median time from admission to effective antibiotic therapy was 0 days [range, 0–2]. Among cases, first-line antibiotic therapy (≤ 72 hours) was temocillin in six (8%) and carbapenems in 39 (54%). Temocillin was given at the median daily dose of 4 g [range, 2–4] after 3 days [range, 2–5] of carbapenems. Patients received temocillin for 81% [range, 70–93] of the effective antibiotic course duration over 11 days [range, 8–14]. The effective antibiotic duration was similar in cases and controls (P = 0.067). Clinical cure at the end of antibiotic therapy was 94% (68/72) in cases vs. 99% (71/72) in controls (P = 0.206), with no difference among immunocompromised and solid organ transplant patients (P > 0.050). ConclusionsTemocillin effectively relayed β-lactams, including carbapenems, to treat (complicated) ESBL-E UTI. Its efficacy was consistent among kidney transplant recipients.

Dual-Function Potentiation by PEG-BPEI Restores Activity of Carbapenems and Penicillins against Carbapenem-Resistant Enterobacteriaceae.

The rise of life-threatening carbapenem-resistant Enterobacteriaceae (CRE) infections has become a critical medical threat. Some of the most dangerous CRE bacteria can produce enzymes that degrade a wide range of antibiotics, including carbapenems and β-lactams. Infections by CRE have a high mortality rate, and survivors can have severe morbidity from treatment with toxic last-resort antibiotics. CRE have mobile genetic elements that transfer resistance genes to other species. These bacteria also circulate throughout the healthcare system. The mobility and spread of CRE need to be curtailed, but these goals are impeded by having few agents that target a limited range of pathogenic CRE species. Against CRE possessing the metallo-β-lactamase NDM-1, Klebsiella pneumoniae ATCC BAA-2146 and Escherichia coli ATCC BAA-2452, the potentiation of meropenem and imipenem is possible with low-molecular weight branched polyethylenimine (600 Da BPEI) and its poly(ethylene glycol) (PEG)ylated derivative (PEG-BPEI) that has a low in vivo toxicity. The mechanism of action is elucidated with fluorescence assays of drug influx and isothermal calorimetry data showing the chelation of essential Zn2+ ions. These results suggested that 600 Da BPEI and PEG-BPEI may also improve the uptake of antibiotics and β-lactamase inhibitors. Indeed, the CRE E. coli strain is rendered susceptible to the combination of piperacillin and tazobactam. These results expand the possible utility of 600 Da BPEI potentiators, where previously we have demonstrated the ability to improve antibiotic efficacy against antibiotic resistant clinical isolates of Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis.

Design of Rapid Detection System for Five Major Carbapenemase Families (bla KPC, bla NDM, bla VIM, bla IMP and bla OXA-48-Like) by Colorimetric Loop-Mediated Isothermal Amplification.

PurposeCarbapenemase-producing Enterobacteriaceae (CPE) infection constitutes a public health threat. Timely and efficient diagnosis is of paramount importance for prompt and effective therapy. In order to quickly and comprehensively detect the five major families of carbapenemases (blaKPC, blaNDM, blaVIM, blaIMP, and blaOXA-48-like), colorimetric loop-mediated isothermal amplification (LAMP) was employed.Materials and MethodsFive sets of LAMP primers were designed, each of which can, respectively, amplify all the carbapenemase subtypes described in this work. Twenty whole genome sequencing-verified-“standard strains”, including 1 blaNDM-1, 1 blaNDM-5, 1 blaNDM-6, 1 blaNDM-7, 2 blaIMP-4, 1 blaIMP-8, 2 blaKPC-2, 1 blaKPC-3, 1 blaKPC-4, 1 blaKPC-5, 1 blaKPC-6, 1 blaKPC-7, 1 blaOXA-48 and 1 blaOXA-181 carrier, and 1 blaVIM and blaOXA-244, 1 blaKPC-2 and blaIMP-4, 1 blaKPC-2 and blaVIM-1 and 1 blaKPC-2 and blaNDM-1-co-carriers, were used to establish a 25-microliter visual LAMP reaction system (kept at 65°C for 30 minutes in water bath). Color change from bright pink to yellow indicated positive amplification. In addition, 126 pre-verified clinical carbapenem-resistant Enterobacteriaceae (CRE) isolates, including 65 CPE (23 blaNDM, 2 blaOXA-48-like, 1 blaKPC and blaVIM, 2 blaIMP, and 37 blaKPC carriers) and 61 non-CPE, were also detected.ResultsWith the lowest detection limit of 10 colony forming units (CFU) per reaction for LAMP and 103 CFU per reaction for PCR, the LAMP system demonstrated dramatically higher sensitivity while retaining the same specificity. Furthermore, we demonstrated concordant results between the two methods for the 126 clinical isolates.ConclusionTherefore, LAMP could be used for rapid identification of the five major carbapenemase gene families in routine clinical laboratories.

Tandem fecal microbiota transplantation cycles in an allogeneic hematopoietic stem cell transplant recipient targeting carbapenem-resistant Enterobacteriaceae colonization: a case report and literature review

BackgroundDue to limited antibiotic options, carbapenem-resistant Enterobacteriaceae (CRE) infections are associated with high non-relapse mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Also, intestinal CRE colonization is a risk factor for subsequent CRE infection. Several clinical studies have reported successful fecal microbiota transplantation (FMT) for the gut decontamination of a variety of multidrug-resistant bacteria (MDRB), even in immunosuppressed patients. Similarly, other studies have also indicated that multiple FMTs may increase or lead to successful therapeutic outcomes.Case presentationWe report CRE colonization in an allo-HSCT patient with recurrent CRE infections, and its successful eradication using tandem FMT cycles at 488 days after allo-HSCT. We also performed a comprehensive microbiota analysis. No acute or delayed adverse events (AEs) were observed. The patient remained clinically stable with CRE-negative stool culture at 26-month follow-up. Our analyses also showed some gut microbiota reconstruction. We also reviewed the current literature on decolonization strategies for CRE.ConclusionsCRE colonization led to a high no-relapse mortality after allo-HSCT; however, well-established decolonization strategies are currently lacking. The successful decolonization of this patient suggests that multiple FMT cycles may be potential options for CRE decolonization.

Fecal carriage of extended spectrum beta-lactamase producing Enterobacteriaceae among HIV infected children at the University of Gondar Comprehensive Specialized Hospital Gondar, Ethiopia

BackgroundHuman immunodeficiency virus (HIV) and extended spectrum beta lactamase (ESBL) producing Enterobacteriaceae infections are the major challenges in sub-Saharan Africa. Data on the carriage rate of ESBL producing Enterobacteriaceae among HIV infected children is lacking in Ethiopia. Hence this study was aimed to investigate fecal carriage of ESBL producing Enterobacteriaceae among HIV infected children at the University of Gondar comprehensive Specialized Hospital.MethodsA cross-sectional study was conducted among HIV infected children from January to April 2020. Stool specimens were collected from 161 study participants by convenient sampling and cultured on MacConkey agar. Biochemical identification, antimicrobial susceptibility testing including ESBL production were carried out. Data were analyzed by SPSS version-20 and P-value < 0.05 on multivariate logistic regression analysis was regarded as statistically significant.ResultsFrom a total of 161 study participants male to female ratio was 1:1.1. Moreover; 96.3% of participants were in HIV stage-I and 90.1% had at least a year highly active antiretroviral therapy exposure. A total of 186 Enterobacteriaceae, with E. coli 60% and K. pneumonia 16.13% predominance were isolated from 161 participants. Majority of isolates were most resistant to amoxicillin (95.1%) and sensitive to CHL (94.1%), CXT (91.4%) and CAZ (91.4%). There were 71(38.17%) multidrug resistant isolates, 13 of which were also ESBL producers. The overall ESBL carriage rate was 32/161 (19.9%). History of antibiotic use was the independent factor associated with ESBL carriage (AOR 3.23 (95% CI 1.054–9.88)) and P-value of 0.04.ConclusionESBL carriage rate of HIV infected children was considerable. Previous antibiotic use was the independent factor. Regular screening for antibiotic resistance on HIV patients before prescription and large-scale antibiotic resistance survey including healthy community may be important.

Incidence of a subsequent carbapenem-resistant Enterobacteriaceae infection after previous colonisation or infection: a prospective cohort study

ObjectivesIn patients with a history of carbapenemase-producing, carbapenem-resistant Enterobacteriaceae (CP-CRE), the need for CP-CRE targeted treatment in subsequent sepsis episodes is unclear. This study aimed to characterise the incidence of subsequent CP-CRE infective episodes in individuals with prior CP-CRE colonisation and/or infection, and identify predictors for these subsequent CP-CRE infections. MethodsAll adult inpatients with CP-CRE detected from any site between June 2012 and May 2014 at a tertiary-care hospital were prospectively followed for two years to assess for any subsequent CP-CRE infections. Potential factors to which patients were exposed during the follow-up period were collected from medical records and analysed. ResultsA total of 171 patients were enrolled. Of 151 patients who entered the follow-up period, 16 (10.6%) developed a subsequent CP-CRE infection. The median time to a subsequent infective episode was 24.5 days (12–105 days). The type of carbapenemase was highly conserved within index and subsequent paired episodes (16 of 17 pairs). Patients with first CP-CRE isolated from intra-abdominal or respiratory sources were ≥7 times more likely to develop a subsequent infection, while most rectal carriers remain colonised. For carriers (n = 133), Klebsiella spp. (OR 4.7) and OXA carbapenemase (OR 9.4) were significant predictors of subsequent infection. In patients with initial infection (n = 18), end-stage renal failure requiring dialysis (OR 22.0) was the only predisposing factor. ConclusionThe incidence of subsequent infections in patients with prior colonisation was low. Consideration for CP-CRE targeted therapy is recommended in patients on dialysis and previous CP-CRE infections involving the bloodstream and/or respiratory tract.

Mortality associated with third generation cephalosporin-resistance in Enterobacteriaceae infections: a multicenter cohort study in Southern China

ABSTRACT Background: Emerging third-generation cephalosporin-resistant Enterobacteriaceae (3GCR-EB) pose global healthcare concern. This study assessed the in-hospital mortality attributed to 3GCR-EB. Methods: The study cohort comprised inpatients with community-onset or healthcare-associated infection caused by Enterobacteriaceae in three tertiary-care public hospitals in 2017. In-hospital mortality was compared between 3GCR-EB infected patients and third-generation cephalosporin-susceptible Enterobacteriaceae (3GCS-EB) infected patients using competing risk survival models. Results: Of 2,343 study patients (median age 60 years; 45.2% male), 1,481 (63.2%) had 3GCS-EB and 862 (36.8%) 3GCR-EB infection. 494 (57.0%) 3GCR-EB isolates were co-resistant to fluoroquinolones and 15 (1.7%) to carbapenems. In-hospital mortality was similar in 3GCS-EB and 3GCR-EB infections (2.4% vs. 2.8%; p = 0.601). No increase in the hazard of in-hospital mortality was detected for 3GCR-EB compared to 3GCS-EB infection (sub-distribution hazard ratio [HR] 0.80; 95%CI, 0.41–1.55) adjusting for patient age, sex, intensive care admission, origin of infection and site of infection. Analysis of cause-specific hazards showed that 3GCR-EB infections significantly decreased the daily rate of hospital discharge (cause-specific HR = 0.84; 95%CI, 0.76–0.92) leading to lengthier hospitalizations. Conclusion: 3GCR-EB infection per se was not associated with increased in-hospital mortality in this study, but placed significant healthcare burden by increasing the length of hospitalization.

Early prediction models for extended-spectrum β-lactamase-producing Escherichia coli infection in emergency department: A protocol for systematic review and meta analysis.

Background:Resistance in gram-negative bacteria has gained great importance in recent decades and one reason is the rapid increase of extended spectrum β-lactamase (ESBL)-producing bacteria as a growing problem worldwide. The increasing proportion of ESBL-producing Enterobacteriaceae (ESBL-E) infections acquired in the emergency community is a new feature of ESBLs epidemiology. Early recognition of patients with extended-spectrum β-lactamase-producing Escherichia coli infection is important in the emergency department. To mitigate the burden on the healthcare system, while also providing the best possible care for patients, early recognition of the infection is needed.Methods:For the acquisition of required data of eligible prospective/retrospective cohort study or randomized controlled trials (RCTs), we will search for publications from PubMed, Web of science, EMBASE, Cochrane Library, Google scholar. Two independent reviewers will read the full English text of the articles, screened and selected carefully, removing duplication. Then we evaluate the quality and analyses data by Review Manager (V.5.4). Results data will be pooled and meta-analysis will be conducted if there's 2 eligible studies considered.Results:This systematic review and meta-analysis will evaluate the value of the early prediction models for Extended-spectrum β-lactamase-producing E coli infection in emergency department.Conclusions:This systematic review and meta-analysis will provide clinical evidence for predicting Extended-spectrum β-lactamase-producing E coli infection in emergency department, inform our understanding of the value of the predictive model in predicting Extended-spectrum β-lactamase-producing E coli infection in emergency department in the early stage. The conclusions drawn from this study may be beneficial to patients, clinicians, and health-related policy makers.Study registration number:INPLASY202130049.

Characteristics of fosA-carrying plasmids in E. coli and Klebsiella spp. isolates originating from food and environmental samples.

Fosfomycin is an important antibiotic for the treatment of MDR Enterobacteriaceae infections. High susceptibility rates are, however, threatened by the spread of plasmids encoding fosfomycin-modifying enzymes. In this study, we sought to characterize the genetic context of fosA in plasmids from Escherichia coli and Klebsiella spp. isolates recovered from food, wastewater and surface water in Switzerland. E. coli and Klebsiella spp. isolates collected between 2012 and 2019 in Switzerland were screened for fosfomycin resistance. Presence of fosA was verified by PCR and sodium phosphonoformate (PPF) disc potentiation testing, and transferability was tested using conjugation assays. Whole-genome sequences including complete fosA-containing plasmids were determined using long- and short-read sequencing. In 11 E. coli and two Klebsiella spp. isolates, high-level fosfomycin resistance was mediated by plasmids containing fosA3 (n = 12) or fosA8 (n = 1). Four isolates harboured a near-identical 45 kb IncN plasmid with fosA3, while replicon types varied in the remaining plasmids. The fosA genes were typically embedded in IS26-bounded transposition units and frequently located in the proximity of blaCTX-M transposition units. Although fosfomycin resistance rates are currently low, the presence of fosA-encoding plasmids circulating in the Enterobacteriaceae population suggests that fosfomycin resistance may rapidly spread upon increased selection pressure. Transposition mobility of fosA and co-location on plasmids with other resistance genes may further promote its dissemination.