ESBL Enterobacteriaceae Research Articles

Successful prophylaxis of ESBL Enterobacteriaceae repetitive urinary tract infections with subcutaneous temocillin: a case report.

Temocillin is an antibiotic belonging to the β-lactam family, introduced in 1988 but soon forgotten because of its narrow spectrum. Recently, it has been repurposed for its effectiveness against ESBL Enterobacteriaceae, and represents an alternative of choice to carbapenems due to its limited impact on the microbiota. We present here a successful case of antibiotic prophylaxis of recurrent ESBL urinary tract infections with subcutaneously administered temocillin. Temocillin is rarely administered subcutaneously and even more rarely in prophylactic situations. However, its tolerance profile and low impact on the microbiota should help reconsideration of its use in particular cases like this one.

Predicting Extended-Spectrum Beta-Lactamase and Carbapenem Resistance in Enterobacteriaceae Bacteremia: A Diagnostic Model Systematic Review and Meta-Analysis.

Enterobacteriaceae bacteremia, particularly when associated with antimicrobial resistance, can result in increased mortality, emphasizing the need for timely effective therapy. Clinical risk prediction models are promising tools, stratifying patients based on their risk of resistance due to ESBL and carbapenemase-producing Enterobacteriaceae in bloodstream infections (BSIs) and, thereby, improving therapeutic decisions. This systematic review and meta-analysis synthesized the literature on the performance of these models. Searches of PubMed and EMBASE led to the identification of 10 relevant studies with 6106 unique patient encounters. Nine studies concerned ESBL prediction, and one focused on the prediction of carbapenemases. For the two ESBL model derivation studies, the discrimination performance showed sensitivities of 53-85% and specificities of 93-95%. Among the four ESBL model derivation and validation studies, the sensitivities were 43-88%, and the specificities were 77-99%. The sensitivity and specificity for the subsequent external validation studies were 7-37% and 88-96%, respectively. For the three external validation studies, only two models were evaluated across multiple studies, with a pooled AUROC of 65-71%, with one study omitting the sensitivity/specificity. Only two studies measured clinical utility through hypothetical therapy assessments. Given the limited evidence on their interventional application, it would be beneficial to further assess these or future models, to better understand their clinical utility and ensure their safe and impactful implementation.

Microbiological quality assessment of fresh produce: Potential health risk to children and urgent need for improved food safety in school feeding schemes.

About 388 million school-going children worldwide benefit from school feeding schemes, which make use of fresh produce to prepare meals. Fresh produce including leafy greens and other vegetables were served at 37% and 31% of school feeding programs, respectively, in Africa. This study aimed at assessing the microbiological quality of fresh produce grown onsite or supplied to South African schools that are part of the national school feeding programs that benefit over 9 million school-going children. Coliforms, Escherichia coli, Enterobacteriaceae, and Staphylococcus aureus were enumerated from fresh produce (n = 321) samples. The occurrence of E. coli, Listeria monocytogenes, Salmonella spp., and extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae was determined. Presumptive pathogens were tested for antimicrobial resistance. E. coli was further tested for diarrheagenic virulence genes. Enterobacteriaceae on 62.5% of fresh produce samples (200/321) exceeded previous microbiological guidelines for ready-to-eat food, while 86% (276/321 samples) and 31.6% (101/321 samples) exceeded coliform and E. coli criteria, respectively. A total of 76 Enterobacteriaceae were isolated from fresh produce including E. coli (n = 43), Enterobacter spp. (n = 15), and Klebsiella spp. (n = 18). Extended-spectrum β-lactamase production was confirmed in 11 E. coli, 13 Enterobacter spp., and 17 Klebsiella spp. isolates. No diarrheagenic virulence genes were detected in E. coli isolates. However, multidrug resistance (MDR) was found in 60.5% (26/43) of the E. coli isolates, while all (100%; n = 41) of the confirmed ESBL and AmpC Enterobacteriaceae showed MDR. Our study indicates the reality of the potential health risk that contaminated fresh produce may pose to school-going children, especially with the growing food safety challenges and antimicrobial resistance crisis globally. This also shows that improved food safety approaches to prevent foodborne illness and the spread of foodborne pathogens through the food served by school feeding schemes are necessary.

A panel of diverse Klebsiella pneumoniae clinical isolates for research and development.

Klebsiella pneumoniae are a leading cause of healthcare-associated infections worldwide. In particular, strains expressing extended-spectrum β-lactamases (ESBLs) and carbapenemases pose serious treatment challenges, leading the World Health Organization (WHO) to designate ESBL and carbapenem-resistant Enterobacteriaceae as 'critical' threats to human health. Research efforts to combat these pathogens can be supported by accessibility to diverse and clinically relevant isolates for testing novel therapeutics. Here, we describe a panel of 100 diverse K. pneumoniae isolates that are publicly available to assist the research community in this endeavour. Whole-genome sequencing (WGS) was performed on 3878 K. pneumoniae clinical isolates housed at the Multidrug-Resistant Organism Repository and Surveillance Network. The isolates were cultured from 63 facilities in 19 countries between 2001 and 2020. Core-genome multilocus sequence typing and high-resolution single-nucleotide polymorphism-based phylogenetic analyses captured the genetic diversity of the collection and were used to select the final panel of 100 isolates. In addition to known multidrug-resistant (MDR) pandemic lineages, the final panel includes hypervirulent lineages and isolates with specific and diverse resistance genes and virulence biomarkers. A broad range of antibiotic susceptibilities, ranging from pan-sensitive to extensively drug-resistant isolates, are described. The panel collection, and all associated metadata and genome sequences, are available at no additional cost and will be an important resource for the research community and for the design and development of novel antimicrobial agents and diagnostics against this important pathogen.

High Fecal Carriage of Extended-Spectrum β-Lactamase Producing Enterobacteriaceae by Children Admitted to the Pediatric University Hospital Complex in Bangui, Central African Republic

Antimicrobial resistance (AMR) is a global public health threat. Quality data on AMR are needed to tackle the rise of multidrug-resistant clones. These data are rare in low-income countries, especially in sub-Saharan Africa. In this study, we investigated the rise of extended-spectrum β-lactamase–producing (ESBL) Enterobacteriaceae in Bangui, Central African Republic. We collected 278 fecal samples from 0–5-year-old children admitted to the Pediatric University Hospital Complex in Bangui from July to September 2021. Enterobacteriaceae were isolated and identified, and their susceptibility to 19 antibiotics was tested. We recovered one and two Enterobacteriaceae species from 208 and 29 samples, respectively. One clone of each species from each sample was further characterized, for a total of 266 isolates. Escherichia coli predominated, followed by Klebsiella. AMR was frequent, with 98.5% (262/266) of the isolates resistant to at least one antibiotic. Additionally, 89.5% (238/266) of the isolates were multidrug resistant, with resistance being frequent against all tested antibiotics except carbapenems and tigecycline, for which no resistance was found. Importantly, 71.2% (198/278) of the children carried at least one ESBL species, and 85.3% (227/266) of the isolates displayed this phenotype. This study confirms the rise of ESBL Enterobacteriaceae in Bangui and stresses the need for action to preserve the efficacy of antibiotics, as crucial for the treatment of bacterial infections.

Treatment of severe infections caused by ESBL or carbapenemases-producing Enterobacteriaceae

Treatment of severe infections caused by ESBL or carbapenemases-producing Enterobacteriaceae

Treatment of severe infections caused by ESBL or carbapenemases-producing Enterobacteriaceae

Enterobacteriaceae are the most frequent pathogens in the Intensive Care Unit. Due to their safety and activity, β-Lactams (BL) and carbapenems represented the most common strategy adopted against these germs. The increasing exposure to these molecules led to the development of several types of antimicrobial resistance as the expression of extended-spectrum β-lactamases (ESBLs) and carbapenemases. Great molecular variability exists among these enzymes, with significant clinical impact.To limit morbidity and mortality, old antibiotics were tested and represent viable alternatives for specific types of infections, or once the spectrum of susceptibility of each germ has been determined. Alongside, new molecules have been specifically designed but enzyme molecular variability prevents the existence of one single antibiotic which fits for all.Therefore, a quicker identification of the molecular identity of each germ, together with the knowledge of the activity spectrum of each antibiotic is crucial to tailor the therapy and make it effective.

Multi-Drug Resistance Profile, Prevalence of Extended-Spectrum Beta-Lactamase and Carbapenemase-Producing Gram Negative Bacilli Among Admitted Patients After Surgery with Suspected of Surgical Site Nosocomial Infection North East Ethiopia.

BackgroundAntibiotic resistance is becoming a global issue, with estimated 2.8 million people in the United States developing antibiotic-resistant diseases each year. The carriage of ESBL and Carbapenemase-producing Enterobacteriaceae among hospitalized patients is a threat to the future of antibiotic treatment.ObjectiveMulti-drug resistance profile, prevalence of extended-spectrum beta-lactamase and Carbapenemase-producing Gram-negative bacilli among admitted patients after surgery with suspected surgical site nosocomial infection north east Ethiopia.Material and MethodsA hospital-based cross-sectional study was conducted from April 2021 to February 2022. Socio-demographic and clinical data were assessed using a structured questionnaire. A total of 384 relevant clinical samples (pus, pus aspirates, and wound swabs) were collected aseptically and processed within 30 min by placing the swabs into the sterile test tubes having 0.5 mL of sterile normal saline. The samples were cultured on MacConkey agar, chocolate agar and blood agar, and species identification was done using standard biochemical tests. Disk diffusion antimicrobial sensitivity test was done on Mueller–Hinton agar. All the cefoxitin resistant Enterobacteriaceae isolates were checked for the presence of AmpC beta-lactamase using four cartridges of disk diffusion tablets. ESBL output validation was conducted by the combination disk test. The production of Carbapenemase was checked using modified carbapenem inactivation method.ResultsThe prevalence of significant bacterial nosocomial infection among surgical site infection 343 (89.32%). S. aureus 125 (36.4%) was predominant followed by E. coli 80 (23.3%) P. aeruginosa 31 (9.03%). The overall MDR rate of isolated bacteria was 251 (73.3%). About 150 (73.9%) bacteria were suspected for ESBL production and 67 (33%) AmpC beta-lactamase and 27 (13.3%) Carbapenemase-producing Gram-negative bacterial, respectively.Conclusions and RecommendationsThe severity of ESBL-PE was critical, and the CPE was alarming. Meropenem and imipenem were the most effective antibiotics against ESBL-producing Enterobacteriaceae. Therefore, strict infection prevention and control measures are needed.

Phenotypic and genotypic distribution of ESBL, AmpC β-lactamase and carbapenemase-producing Enterobacteriaceae in community-acquired and hospital-acquired urinary tract infections in Sri Lanka

Although Sri Lanka belongs to a region with a high prevalence of extended-spectrum β-lactamase (ESBL), AmpC β-lactamase and carbapenemase-producing Enterobacteriaceae, data regarding antimicrobial resistance (AMR) is limited. We studied the prevalence and diversity of β-lactamases produced by Enterobacteriaceae urinary pathogens from two hospitals in the Western Province of Sri Lanka. ESBL, AmpC β-lactamase and carbapenemase production was detected by phenotypic testing followed by genotyping. The species responsible for urinary tract infections (UTI) were Escherichia coli (69%), Klebsiella pneumoniae (16%) and Enterobacter sp (6%). The prevalence of ESBL (50%), AmpC β-lactamase (19%) and carbapenemase (11%) phenotypes was high, and greater in hospital-acquired (HA-UTI) (75%) than in community-acquired UTI (CA-UTI) (42%). Identification of CA-UTI caused by carbapenemase-producing Enterobacteriaceae (5%) is alarming. Only one ESBL gene, blaCTX-M-15, was detected. AmpC β-lactamase genes found in E.coli and K. pneumoniae were blaCMY-2, blaCMY-42 and blaDHA-1, while Enterobacter sp. carried blaACT-1. Carbapenemase genes were blaNDM-1, blaNDM-4, blaOXA-181 and blaOXA-232, while blaKPC, blaIMP and blaVIM were absent. Co-occurrence of multiple bla genes, with some isolates harbouring six different bla genes, was common. Carbapenem-resistant isolates without carbapenemase genes displayed mutations in the outer membrane porin genes, ompF of E. coli and ompK36 of K.pneumoniae. Factors associated with UTI with β-lactamase-producing Enterobacteriaceae were age ≥50 years, previous hospitalization, presence of an indwelling urinary catheter, history of diabetes mellitus or other chronic illness and recurrent urinary tract infections. This study adds to the currently scarce data on AMR in Sri Lanka.

Genomic and Phenotypic Characterisation of Multi-Drug ResistantEscherichia coli carried by meat handlers and slaughterhouse meat from North-Western Tanzania

Our research is part of a larger project Supporting the National Action Plan on Antimicrobial Resistance (SNAP-AMR) in Tanzania. The aspect of this work is to determine the AMR carriage and associated mobile genetic elements of extended spectrum β-lactamase (ESBL) producing Escherichia coli within the community of Mwanza, in North-Western Tanzania. From 54 slaughterhouses a total of 322 E. coli isolates were obtained from raw meat, with 210 originating from meat handlers. Initial antimicrobial susceptibility testing identified 71 (22%) and 27 (13%) of the meat and meat handler isolates, respectively, as being ESBL E. coli. ST2852 was the most abundant MLST, followed by globally disseminated and ESBL associated ST38. Whole genome sequencing and phenotypic analysis revealed 88% of our isolates were resistant to three or more antimicrobial classes. On average, our isolates carried at least 10 different AMR associated genes, with 80% having one or more AMR conferring chromosomal mutation. In relation to ESBL, 88 out of 98 of the isolates carried the globally disseminated allotype blaCTX-M-15, with over 55% of the isolates encoding blaCTX-M-15on multi-drug resistant (MDR) plasmids. The remaining strains encoded one of three different blaCTX-Mallotypes. Our data highlights high prevalence of MDR ESBL E. coli within the community and its potential risk of transmission through the food chain. In our future work, we will combine these community carriage data with our work on ESBL Enterobacteriaceae carriage and infection within healthcare settings, to evaluate the genomic epidemiology of ESBL organisms in this region.

Tigecycline susceptibility among multi-drug resistant bacteria: A 7-year retrospective study

The emergence and spread of multidrug-resistant bacteria (MDR) are major public health issues worldwide. The objective of this study is to evaluate the microbiological efficacy of tigecycline against multi-drug-resistant bacteria and to explore its potential place in clinical practice. A retrospective study was carried out over 7 years, from January 2015 to December 2021, at the Avicenne Military Hospital. Were collected all bacteriological samples received for diagnostic purposes at the microbiology laboratory. Tigecycline susceptibility was tested among 846 isolates among the 4293 isolates during the study period. The overall frequency of MDR bacteria was of 14,3%. 60% of the MDR bacteria isolated were susceptible, 35% were declared resistant and 5% were declared intermediate. Co-resistance levels in MDR bacteria are high. Tigecycline remained active in vitro on most of the MDR bacteria tested. The susceptibility rates for tigecycline found were respectively 76%, 57%, and 34%, for the ESBL Enterobacteriaceae strains, the CPEs, and the multi-drug resistant Acinetobacter baumanii strains. In this study, the MDR bacteria isolated showed overall satisfying susceptibility rates to tigecycline.

First report on the molecular characterization and the occurrence of extended‐spectrum β‐lactamase producing Enterobacteriaceae in unpasteurized bovine's buttermilk

AbstractThe dairy products have been reported as a source of extended‐spectrum β‐lactamase (ESBL)‐producing bacteria. The aim of this study is to determine the potential transfer of ESBL Enterobacteriaceae to humans due to the consumption of buttermilk made from raw, unpasteurized milk collected in Batna province (Northeast of Algeria) as well as to identify isolates and genes encoding resistance in these isolates. Two hundred and forty‐three samples of buttermilk made from raw, unpasteurized milk were collected and screened for the presence of ceftazidime‐resistant Enterobacteriaceae. The suspected isolates were identified by molecular methods. Enterobacteriaceae isolates were subjected to antimicrobial susceptibility testing and were examined phenotypically for ESBL production and confirmed by using PCR assay and DNA sequencing. Thirteen ceftazidime‐resistant Enterobacteriaceae were observed at a rate of 5.76% including Escherichia coli (n = 4), Klebsiella pneumoniae (n = 4), Klebsiella oxytoca (n = 1), Hafnia paralvei (n = 3), and Citrobacter freundii (n = 1). Eight Enterobacteriaceae (61.53%, 8) revealed multidrug resistance, while (61.53%, 8) were confirmed as ESBL‐producing Enterobacteriaceae. Polymerase chain reaction assay revealed that blaTEM (87.5%, 7) was the most common gene, followed by the blaCTX‐M gene (75%, 6) and finally the blaSHV gene (50%, 4). The sequencing of genes identified blaTEM‐1D, blaSHV‐1, and blaSHV‐11. Our findings signified that buttermilk made from raw, unpasteurized milk could be the reservoir for the prevalence of ESBL‐producing Enterobacteriaceae and the potential source of transmission for the consumer. Pasteurization of buttermilk is critical to reduce the risk associated with ESBL‐producing isolates.

#48: Perinatal Transmission of Multi-Drug Resistant Enterobacteriaceae

Abstract Background There is a global rise in multi-drug resistant (MDR) Gram-negative Enterobacteriaceae. Both maternal and neonatal gut colonization with pathogenic E. coli is associated with risk of invasive infection in infancy. Infections caused by MDR strains have delayed effective therapy and higher morbidity. Additionally, extended spectrum beta-lactamase producing (ESBL) E. coli are persistent gut colonizers. Perinatal transmission of ESBL E. coli could therefore have profound impact on the infant microbiota and health. Our aims were to 1) Determine the burden of ESBL Enterobacteriaceae (ESBL-E) colonization and rate of perinatal transmission among healthy mother-infant dyads in the Chicago area and 2) Compare rates of perinatal transmission among commensal, antibiotic-susceptible human E. coli strains versus ESBL E. coli strains in a mouse model. Methods This is an ongoing prospective study of healthy mothers and term infants born vaginally between 7/2020-11/2020. Maternal demographic and medical history data were collected, including age, race/ethnicity, international travel, and pregnancy/delivery information. Maternal rectal and vaginal swabs (n=62) were collected during labor. Clinical samples were initially grown in media supplemented with ampicillin and vancomycin to suppress growth of most susceptible commensal organisms. The sample was then plated on MacConkey agar (+/-ceftriaxone). We also developed a mouse model of perinatal transmission to determine the rate of transmission among ESBL E. coli compared to the commensal E. coli strain MG1655 and the pan-sensitive uropathogenic E. coli strain UTI89. Pups were sacrificed at 24–48 hours of life or 7 days of life, and presence of antibiotic resistant E. coli was noted. Results Human: Median maternal age was 32 years (IQR 30–35). Race was primarily white (84%), 11% Asian, and 10% were of Latina ethnicity. There were 30 (48%) female infants, and 42 (68%) infants received exclusive breastmilk. About half of the mothers reported international travel in the past 2 years (28/62, 45%), and 17/62 (27%) were born outside the USA. Ampicillin resistant (Amp-R) Enterobacteriaceae were recovered from rectal samples of 59/62 (95%) and vaginal samples of 16/62 (26%) mothers. Ten of 62 (16%) mothers were colonized with ESBL-E. Over half of infant stool samples (27/49, 55%) grew Amp-R Enterobacteriaceae. Of 6 mother-infant dyads with maternal ESBL-E colonization and infant stool available, 2 (33%) infants grew out ESBL-E. Murine We tested 4 ESBL E. coli strains and 2 control strains (MG1655 and UTI89) in our perinatal transmission model. We noted that while all strains adequately colonized the gut of the dams, only 2 (ST132 and ST511) of the 4 ESBL E. coli strains and none of the control strains were transmitted efficiently to the mouse pups (Figure 1). Conclusions There is notable community colonization of resistant Enterobacteriaceae among healthy mothers in Chicago with significant transmission to infants. Murine model data shows that human ESBL E. coli strains can colonize pregnant dams, and some ESBL E. coli strains appear to be perinatally transmitted more efficiently than non-drug resistant and commensal E. coli strains. Persistence of colonization, genomic factors related to transmission, and impact on the developing infant microbiome are future directions of study.

A rare case of periprosthetic Trueperella bernardiae following a total hip arthroplasty and antimicrobial stewardship

Trueperella bernardiae is a rare, anaerobic Gram-positive bacillus. Very few published clinical reports1 of Trueperella infections, eludes its true incidence and pathogenicity. We share a case of a 70-year-old woman with recurrent peri-prosthetic joint infection (PJI) following a total hip arthroplasty. A month after hip replacement, she presented with PJI, which was treated with extensive debridement and oral Ciprofloxacin in community for ESBL Enterobacteriaceae from peri-prosthetic samples. Five months later, she represented with peri-prosthetic collection which grew Trueperella bernardiae, during stage 1 hip revision. This was treated in hospital with six-weeks intravenous (IV) benzyl penicillin. A month after the second stage revision, she presents with hip re-collection that grew ciprofloxacin resistant Escherichia coli. She was managed in community with a 6-week IV carbapenem. However, 12 months later she developed a psoas abscess and subsequently elected for cessation of active management, leading to her demise. This report emphasises on the emergence of antimicrobial resistance2 Enterobacteriaceae due to constant antibiotic pressure, possibly causing a prosthetic joint infection by a rare Trueperella bernardiae, which was treated effectively by a narrow spectrum penicillin. This case report calls the need for antimicrobial stewardship3 while elucidating the existence of rare pathogens. 1.Loïez C, Tavani F, Wallet F, et al. An unusual case of prosthetic joint infection due to Arcanobacterium bernardiae. J Med Microbiol 2009; 58: 842–3.2.Serwecińska L. Antimicrobials and antibiotic-resistant bacteria: a risk to the environment and to public health. Water 2020; 12: 3313.3.McKenzie D, Rawlins M, Del Mar C. Antimicrobial stewardship: what’s it all about? Aust Prescr 2013; 36: 116–20.

PROPORTION OF ESBL AND CARBAPENEMASE PRODUCING ENTEROBACTERIACEAE CAUSING BLOODSTREAM INFECTIONS AND SHOWING MULTI DRUG RESISTANCE IN INFECTED PATIENTS IN TERTIARY CARE HOSPITAL AT AGARTALA, TRIPURA

BACKGROUND: Enrerobacteriaceae species are the major leading cause of bloodstream infections in many developing countries. Moreover, ESBL and Carbapenemase-producing Enterobacteriaceae species are often associated with high resistance to a wide class of antibiotics. There are few studies regarding the bloodstream infections causing by Enterobacteriaceae with the production of Extended-spectrum β-lactamases and Carbapenemase enzymes in Tripura, North-East India. This study aimed to determine the “ proportion of ESBL and carbapenemase-producing Enterobacteriaceae causing bloodstream infection and showing Multi-drug resistance (MDR) in infected patients'' in Tertiary care Hospital at Agartala, Tripura. METHOD: Blood samples were collected from all indoor and outdoor patients suspected of Bloodstream infection. Then specimens were inoculated in various culture media after that with this culture isolates we performed gram staining and many biochemical tests (as per CLSI guidelines) to identies the Enterobacteriaceae species. And the production of β-lactamases and Carbapenemase was conrmed by the combined disk test and Modied Hodge method. RESULTS: In this study out of 760 samples processed in the laboratory 77 (10.13%) was tested positive for bacteremia from which 42 (54.54%) blood specimens were infected by Enterobacteriaceae. The members of the Enterobacteriaceae family isolated in patient samples are E.coli (22/42, 52.38%), K. pneumoniae (11/42, 52.38%) others are Enterobacter spp. (8/42, 52.38%) and S.typhi(1/42, 2.38%). In all 42 Enterobacteriaceae species, 17 (40.47%) isolates were found ESBL positive on antibiotic screening which is conrmed by Combined disc diffusion test, and out of 17 Beta-lactamase producers 8 (47.05%) were E. coli, 5 (29.41%) were K. pneumoniae and 4 (23.52%) were Enterobacter spp. And among 42 isolates of Enterobacteriaceae 16 (38.09%) isolates showed Carbapenemase producers, in that 8 (50%) were E.coli, 5 (31.25%) were K. pneumoniae, and 3 (18.75%) were Enterobacter spp. CONCLUSION: This study aims to provide an early, rapid, and effective phenotypic method for identifying Multi-drug resistant (MDR) Bloodstream infections (BSIs) causing by the species of the Enterobacteriaceae family

High rate of multidrug-resistant Enterobacteriaceae carrying ESBL and plasmid-borne AmpC ß-lactamase in a Malaysian community

Background: Even though Southeast Asia is generally regarded as the hotspot for antibiotic resistance, there have been limited studies investigating the prevalence of antibiotic resistance among healthy people in the region. We aimed to investigate the prevalence of two ß-lactamase genes, ESBL and plasmid-borne AmpC (pAmpC) among Enterobacteriaceae in a healthy community in Malaysia. Methods and materials: We collected stool samples and screened for ESBL and pAmpC-producing Enterobacteriaceae using phenotypic and genotypic methods. The susceptibility profile of the isolates towards 13 different antibiotics was observed. Plasmid replicon group, E. coli phylogenetic group and MLST analyses were also conducted to observe the spread pattern of these resistance genes. Risk factors associated with the carriage of ESBL or pAmpC-producing Enterobacteriaceae were then analysed. Results: ESBL and pAmpC production was observed in 21.6% (95% CI 13.9–28.8%) and 32.1% (95% CI 24.5–38.9%) of the participants, respectively. A high proportion of the isolates (99.9%, 95% CI 98.6–99.9%) were multidrug-resistant regardless of the resistance genes carried. Although E. coli B2:ST131 was detected, there was no dominance of a specific clonal strain. Possession of multiple plasmid groups was common, with incFIB being the most frequently detected type. Mixed effect logistic regression analysis found that ESBL production was associated with having allergy (p = 0.01, OR 3.86, 95% CI 1.32–11.23) and consumption of chicken meat (p = 0.02, OR = 8.66, 95% CI = 1.40–53.29), while consumption of fermented food significantly lowers the risk of colonisation with pAmpC producing Enterobacteriaceae (p = 0.02, OR 0.23, 95% CI = 0.06–0.79). Conclusion: The high prevalence of ß-lactamase and multidrug resistance suggests that antibiotic resistance is endemic among healthy people in Malaysia.

Molecular characterization of invasive Enterobacteriaceae from pediatric patients in Central and Northwestern Nigeria.

BackgroundBacteremia is a leading cause of mortality in developing countries, however, etiologic evaluation is infrequent and empiric antibiotic use not evidence-based. Here, we evaluated the patterns of ESBL resistance in children enrolled into a surveillance study for community acquired bacteremic syndromes across health facilities in Central and Northwestern Nigeria.MethodBlood culture was performed for children aged less than 5 years suspected of having sepsis from Sept 2008-Dec 2016. Blood was incubated using the BACTEC00AE system and Enterobacteriacea identified to the species level using Analytical Profile Index (API20E®). Antibiotic susceptibility profile was determined by the disc diffusion method. Real time PCR was used to characterize genes responsible for ESBL production.ResultOf 21,000 children screened from Sept 2008-Dec 2016, 2,625(12.5%) were culture-positive. A total of 413 Enterobacteriaceae available for analysis were screened for ESBL. ESBL production was detected in 160 Enterobacteriaceae, high resistance rates were observed among ESBL-positive isolates for Ceftriaxone (92.3%), Aztreonam (96.8%), Cefpodoxime (96.3%), Cefotaxime (98.8%) and Trimethoprim/sulfamethoxazole (90%), while 87.5%, 90.7%, and 91.9% of the isolates were susceptible to Imipenem, Amikacin and Meropenem respectively. Frequently detected resistance genes were blaTEM—83.8% (134/160), and, blaCTX-M 83.1% (133/160) followed by blaSHVgenes 66.3% (106/160). Co-existence of blaCTX-M, blaTEM and blaSHV was seen in 94/160 (58.8%), blaCTX-M and blaTEM in 118/160 (73.8%), blaTEM and blaSHV in 97/160 (60.6%) and blaCTX-M and blaSHV in 100/160 (62.5%) of isolates tested.ConclusionOur results indicate a high prevalence of bacteremia from ESBL Enterobacteriaceae in this population of children. These are resistant to commonly used antibiotics and careful choice of antibiotic treatment options is critical. Further studies to evaluate transmission dynamics of resistance genes could help in the reduction of ESBL resistance in these settings.

In vitro fosfomycin study on concordance of susceptibility testing methods against ESBL and carbapenem-resistant Enterobacteriaceae

ObjectivesThe increasing emergence and diffusion of multidrug-resistant (MDR) pathogenic bacteria, both in hospital and community settings, is inducing clinicians to reconsider old antibiotics, such as fosfomycin, to overcome the difficulties posed by these microorganisms. Recent studies have reported good in vitro activity of fosfomycin against extended spectrum ß-lactamases (ESBL) and carbapenem-resistant Enterobacteriaceae. The aim of this study was to assess thein vitro activity of fosfomycin by different methods against 120 clinical MDR isolates. MethodsFosfomycin minimum inhibitory concentrations were determined using the agar dilution reference method (AD), gradient test (GT), broth microdilution method (BMD), according to CLSI recommendations, and automated systems (VITEK 2 and BD Phoenix) against 85 carbapenem-resistant Klebsiella pneumoniae and 35 ESBL-producing Escherichia coli. Agreement and discrepancies between the evaluated methods and the reference method were calculated. ResultsFosfomycin showed very good activity against ESBL-producing E. coli (88.6%). Excellent agreement (100%) between the three (AD, BMD and GT) susceptibility methods was found for E. coli. No major errors were observed. The fosfomycin resistance rate ranged from 24% (KPC-producing) to 100% (NDM-OXA-48 co-producing) K. pneumoniae. For all carbapenem-resistant K. pneumoniae strains, categorical agreement was >90% for all methods except for VITEK 2, which was 84%. ConclusionsWhen ESBL E. coli isolates are found to be susceptible to fosfomycin with automated systems, it is not necessary to verify these results with the AD reference method; while for resistant strains, the GT can be used. In cases of KPC K. pneumoniae resistant to fosfomycin, the AD method is the only reference method.

Epidemiology of Positive Blood Cultures due to Multidrug-Resistant Organisms From an Academic Center and Community Hospitals

Background: Multidrug-resistant organisms (MDROs) are a threat to public health. The objective of this study was to define risk factors and outcomes of patients with positive blood cultures due to MDROs in 2 rural community hospitals as compared to a tertiary-care academic center. Methods: Retrospective cohort study with IRB approval from 1 tertiary-care academic center and 2 rural community hospitals (Barnes-Jewish [BJH], Parkland Health Center, and Missouri Baptist Sullivan Hospital) from July 1, 2013, to August 1, 2018. Demographics, comorbidities, procedures, outcomes, and blood and urine culture data were collected from the BJH informatics database for hospitalized patients with positive blood cultures due to MDROs. MDROs were defined according to European and US CDC standards. Results: Of the patients with positive blood cultures growing organisms with the potential to be MDR, 1,065 (55%) blood cultures grew MDROs from the academic center and 157 (33%) grew MDROs from the 2 community hospitals (P < .0001). Among these, methicillin-resistant Staphylococcus aureus (35% at BJH and 37% at community hospitals) and MDR Enterobacteriaceae (29% at BJH and 36% at community hospitals) were the most common organisms grown from blood cultures at all hospitals. Among patients with positive MDRO blood cultures, 60% were males and 69% were white, with a mean age of 58 years at BJH. At the community hospitals, 47% were male and 99% were white, with a mean age of 66 years. The most common comorbidity in patients with MDRO bacteremia at BJH was cancer, compared to diabetes at the community hospitals. At all hospitals, >33% of patients with MDRO bacteremia required an ICU stay. Also, 17% of patients with MDRO bacteremia at BJH died during hospitalization compared to 4% at the community hospitals. Among individuals with positive MDRO blood cultures, 9% had a matching isolate from a urine culture at BJH and 46% had a matching urine isolate at the community hospitals. Conclusions: At an academic medical center, the most common organisms identified in MRDO-positive blood cultures included MRSA, MDR Enterobacteriaceae, and VRE. However, at the community hospitals, MRSA, MDR Enterobacteriaceae, and ESBL Enterobacteriaceae were most common. Patients with a positive MDRO blood culture were more likely to have a matching isolate from urine culture at a community hospital compared to the academic center. Further research is needed regarding risk factors and interventions to prevent, detect, and treat MDRO infections.Funding: NoneDisclosures: Margaret A. Olsen reports consulting fees for contract research from Pfizer, Merck, and Sanofi Pasteur.

Extended Spectrum β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae from Broiler Liver in the Center of Algeria, with Detection of CTX-M-55 and B2/ST131-CTX-M-15 in Escherichia coli.

This study aimed to determine the prevalence and diversity of extended-spectrum β-lactamase (ESBL)-producing and multidrug-resistant (MDR) Escherichia coli and Klebsiella pneumoniae isolates from 136 broiler livers randomly purchased in 136 retail markets in Djelfa (Algeria). Isolation was performed on Hektoen agar and bacterial identification was carried out by API20E system and Maldi-TOF-MS (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry). Antimicrobial susceptibility was tested by the disk diffusion and agar dilution methods. Detection of ESBLs and other resistance and integron genes, phylogenetic grouping, and molecular typing was performed by PCR and sequencing. Seventy-eight isolates (one per positive sample) were recovered: 73 E. coli and 5 K. pneumoniae. Among E. coli, 86.3% of isolates were MDR. ESBL activity was revealed in eight E. coli and five K. pneumoniae isolates (rates of 5.9% and 3.7% in analyzed samples, respectively). ESBL genes detected among E. coli were as follows (number of isolates): blaCTX-M-15 (3), blaCTX-M-1 (3), blaCTX-M-55 (1), and blaSHV-12 (1); all ESBL-producing K. pneumoniae isolates carried the blaCTX-M-15 gene. ESBL-producing E. coli isolates were assigned to lineages (phylogroup/sequence type and number of isolates in parenthesis): A/ST48 (1), B1/ST6448 (1), B1/ST5087 (3), B1/ST23 (1), and B2/ST131 (two blaCTX-M-15 E. coli isolates). K. pneumoniae isolates were ascribed to sequence types ST2010 and ST3483. Regarding the 65 non-ESBL E. coli isolates, the most observed resistance genes were as follows: tet(A) (75%), blaTEM (57.1%), and sul2 (43.5%). Class1 integrons were revealed in seven non-ESBL E. coli isolates (10.7%) and two gene-cassette arrays were identified: dfrA1 and aadA1+dfrA1. Our study provides evidence that broiler-derived food from Center of Algeria constitutes a source of ESBL and/or MDR-producing Enterobacteriaceae, with detection of relevant ESBL genes and epidemic clones.