Risk factors for extended-spectrum beta-lactamase producing Escherichia coli and Klebsiella pneumoniae acquisition in a neonatal intensive care unit

Bacterial and Candida Colonization of Neonates in a Regional Hospital in South Africa

BACKGROUND

Neonatal colonization with multidrug-resistant (MDR) Enterobacter spp., Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterococcus faecium (ESKAPE) and Candida spp. often precedes invasive hospital-acquired infections. We investigated the prevalence and dynamics of neonatal ESKAPE and Candida spp. colonization from hospital admission until discharge (or death) and followed up for invasive disease.

METHODS

Prospective longitudinal surveillance for neonatal ESKAPE and Candida spp. colonization was conducted over 6 months at a South African regional hospital. Neonates enrolled at birth had swabs (nasal, 2× skin and rectal) collected within 24 hours and every 48-96 hours thereafter, until discharge or death. ESKAPE and Candida spp. were cultured for and antimicrobial susceptibility was performed on bacterial isolates. Whole-genome sequencing was undertaken on paired samples with the same bacterial species from colonizing and invasive disease episodes in the same child.

RESULTS

Of 102 enrolled neonates, 79% (n = 81) were colonized by ≥1 ESKAPE organism by time of discharge or death. Forty-four percent (36/81) were colonized within 24 hours of birth. Common colonizers were K. pneumoniae (70%; n = 57) and Enterobacter spp. (43%; n = 35). Almost all MDR organisms (93%) were Gram-negative. Forty-two (45%, 42/93) newborns acquired Candida spp. (skin only) colonization, commonly Candida parapsilosis (69%; n = 29). For 2 children with K. pneumoniae colonization and sepsis, the bloodstream and colonizing isolates were genetically different, whereas the single A. baumannii colonizing and blood isolate pair were genetically identical.

CONCLUSIONS

We report a high prevalence of MDR ESKAPE and Candida spp. colonization in a regional neonatal unit. Interventions to reduce the high incidence of hospital-acquired neonatal infections should include reducing high colonization rates.

Gut acquisition of Extended-spectrum β-lactamases-producing Klebsiella pneumoniae in preterm neonates: Critical role of enteral feeding, and endotracheal tubes in the neonatal intensive care unit (NICU)

BACKGROUND

Klebsiella spp. can colonize the intestine of preterm neonates, and over-growth has been associated with necrotizing enterocolitis, hospital-acquired infections, and late-onset sepsis. This could lead us to suggest that the clinical pertinence of intestinal colonization with ESBL in preterm neonates appears to be important. We conducted this study to characterize the genetic proprieties of ESBL-producing Klebsiella pneumoniae (ESBL-KP) under clinical isolates and to describe the risk factors for the intestinal tract acquisition event during hospitalization.

METHODS

One hundred and thirteen premature infants were recruited from the neonatal intensive care unit (NICU). All newborns are issued from the birth suites of the pregnancy department. Two rectal swabs were planned to define K. Pneumoniae intestinal carriage status. ESBL-KP was confirmed by Brilliance ESBL selective chromogenic Agar. Antimicrobial susceptibility testing including phenotypic testing and genotypic detection of the most commonly described ESBL genes was done. Logistic regression models were performed to find the variables associated with the acquisition event of ESBL-KP.

RESULTS

A total of 62 (54.86%) premature neonates were colonized with ESBL-KP. The rate of blaSHV, blaTEM, blaCTX-M1, blaCTX-M2, blaCTX-M9, and blaOXA-48 genes among the isolates was 82, 48, 93.5, 4.8, 11.2 and 3.22%, respectively. We found that ESBLs K. Pneumoniae isolates were 100% resistant to amoxicillin, clavulanic acid-amoxicillin, cefotaxime, ceftazidime, and gentamicin. The regression model is for a given significant association between the tract intestinal of ESBL-KP acquisition events and the use of enteral tube feeding (OR = 38.46, 95% CI: 7.86-188.20, p-Value: 0.001), and endotracheal tubes (OR = 4.86, 95% CI: 1.37-17.19, p-Value 0.014).

CONCLUSION

Our finding supposes that the enteral feeding tube and endotracheal tube might have a critical role in colonizing the intestinal tract of preterm infants. This highlights the current status of both practices that will require updated procedures in the NICU.

Application of Next-Generation Sequencing to Enterobacter Hormaechei Subspecies Analysis during a Neonatal Intensive Care Unit Outbreak

INTRODUCTION

The Enterobacter cloacae complex (ECC) species are potential neonatal pathogens, and ECC strains are among the most commonly encountered Enterobacter spp. associated with nosocomial bloodstream infections. Outbreaks caused by ECC can lead to significant morbidity and mortality in susceptible neonates. At the molecular level, ECC exhibits genomic heterogeneity, with six closely related species and subspecies. Genetic variability poses a challenge in accurately identifying outbreaks by determining the clonality of ECC isolates. This difficulty is further compounded by the limitations of the commonly used molecular typing methods, such as pulsed field gel electrophoresis, which do not provide reliable accuracy in distinguishing between ECC strains and can lead to incorrect conclusions. Next-generation sequencing (NGS) offers superior resolution in determining strain relatedness. Therefore, we investigated the clinical pertinence of incorporating NGS into existing bundle measures to enhance patient management during an outbreak of ECC in a level-3 neonatal intensive care unit (NICU) in Germany.

METHODS

As the standard of care, all neonates on the NICU received weekly microbiological swabs (nasopharyngeal and rectal) and analysis of endotracheal secretion, where feasible. During the 2.5-month outbreak, colonisation with ECC was detected in n = 10 neonates. The phylogenetic relationship and potential antimicrobial resistance genes as well as mobile genetic elements were identified via bacterial whole-genome sequencing (WGS) using Illumina MiSeq followed by in silico data analysis.

RESULTS

Although all ECC isolates exhibited almost identical antimicrobial susceptibility patterns, the WGS data revealed the involvement of four different ECC clones. The isolates could be characterised as Enterobacter hormaechei subspecies steigerwaltii (n = 6, clonal), subsp. hoffmannii (n = 3, two clones) and subsp. oharae (n = 1). Despite the collection of environmental samples, no source of this diffuse outbreak could be identified. A new standardised operating procedure was implemented to enhance the management of neonates colonised with MRGN. This collaborative approach involved both parents and medical professionals and successfully prevented further transmission of ECC.

CONCLUSIONS

Initially, it was believed that the NICU outbreak was caused by a single ECC clone due to the similarity in antibiotic resistance. However, our findings show that antibiotic susceptibility patterns can be misleading in investigating outbreaks of multi-drug-resistant ECC. In contrast, bacterial WGS accurately identified ECC at the clonal level, which significantly helped to delineate the nature of the observed outbreak.

Antimicrobial Resistance Among Gram-Negative Bacteria Isolated in the Newborn Intensive Care Unit at ABDERREZAK-BOUHARA Hospital of Skikda, Algeria

Background: This study aimed to determine the epidemiology of gram-negative bacteria (GNB) isolated in the newborn intensive care unit (NICU) population, to assess their antibiotic susceptibility patterns and possible associated risk factors. Methods: All neonates admitted to the NICU of ABDERREZAK-BOUHARA hospital (Skikda, Algeria) with a clinical diagnosis of neonatal infections from March to May 2019 were included in the study. The extended-spectrum β-lactamase (ESBLs), plasmidic cephalosporinase (pAmpC), and carbapenemases genes were screened by polymerase chain reaction (PCR) and sequencing. PCR amplification of oprD among carbapenem-resistant Pseudomonas aeruginosa isolates was also performed. The clonal relatedness of the ESBLs isolates was studied using multilocus sequence typing (MLST). Results: Among 148 clinical specimens, 36 (24.3%) GNB strains were isolated from urine (n = 22), wound (n = 8), stool (n = 3), and blood (n = 3) samples. The bacterial species identified were Escherichia coli (n = 13), Klebsiella pneumoniae (n = 5), Enterobacter cloacae (n = 3), Serratia marcescens (n = 3), Salmonella spp. (n = 3), Proteus mirabilis (n = 1), P. aeruginosa (n = 5), and Acinetobacter baumannii (n = 3). PCR and sequencing showed that eleven Enterobacterales isolates harbored the bla_CTX-M-15 gene, two E. coli isolates harbored the bla_CMY-2 gene, and three A. baumannii isolates harbored both bla_OXA-23 and bla_OXA-51 genes. Also, five strains of P. aeruginosa were found to harbor mutations in the oprD gene. MLST showed that the K. pneumoniae strains belonged to ST13 and ST189, E. coli belonged to ST69, and E. cloacae belonged to ST214. Different risk factors that could predict positive GNB cultures were found, including female sex, Apgar score <8 at 5 min of life, enteral nutrition, antibiotic use, and extended length of hospitalization. Conclusion: Our study highlights the importance of determining the epidemiology of pathogens causing neonatal infections, their sequence types (ST), and their antibiotic susceptibility patterns to address rapidly a correct antibiotic treatment regimen.

Risk Factors Associated with Multi-Drug Resistance in Neonatal Sepsis Caused by Escherichia coli

Background and Objective

An increasing number of cases of neonatal sepsis due to extended-spectrum beta-lactamase (ESBL)-producing multi-drug resistant (MDR) Escherichia coli (E. coli) have been reported worldwide. The aim of this study was to explore the risk factors associated with ESBL-producing MDR E. coli among neonates with culture-confirmed E. coli sepsis and thereby to help selection of appropriate empirical antibiotics.

Patients and Methods

All newborn infants with a confirmed pathogen isolated from blood or cerebrospinal fluid (CSF) from 2016 to 2021 were identified and those with E. coli infection were included in this analysis. We compared a group of neonatal patients with ESBL-producing MDR E. coli sepsis (n=69) to a group with ESBL-negative E. coli (n=70) based on antimicrobial susceptibility reports. We used multivariable regression analysis to determine the risk factors associated with ESBL-producing MDR E. coli strains among the neonates with culture-confirmed E. coli sepsis.

Results

ESBL-producing MDR E. coli sepsis was more common in premature infants and newborns with hospital-acquired late-onset sepsis (HALOS). The mortality rate of neonatal sepsis caused by ESBL-producing E. coli was about twice as that of sepsis caused by ESBL-negative E. coli. Antepartum exposure to cephalosporins (OR=25.191, 95% CI: 3.184-199.326, P<0.01) and parenteral nutrition for more than 1 week (OR=4.495, 95% CI: 2.009-10.055, P<0.01) were independent risk factors for neonatal infection with ESBL-producing stains among infants with E. coli sepsis.

Conclusion

E. coli remains the most common Gram-negative bacterial pathogen causing neonatal sepsis. A higher proportion of ESBL-producing MDR E. coli is seen in premature infants and those newborns with HALOS and is associated with higher mortality. Antepartum use of cephalosporins and prolonged use of parenteral nutrition may be important factors to consider in the selection of empirical antibiotics for use in neonatal sepsis caused by gram-negative rods prior to the availability of the results of antimicrobial susceptibility.

Whole Genome Sequencing of Extended-Spectrum Beta-Lactamase-Producing Klebsiella pneumoniae Isolated from Neonatal Bloodstream Infections at a Neonatal Care Unit, Algeria

Aims: Neonatal bloodstream infections (BSIs) are an important cause of mortality among neonates. Besides, extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-Kp) is one of the most frequent pathogens causing neonatal BSIs. This study aimed to characterize ESBL-Kp strains recovered from neonatal BSI and to investigate risk factors associated with ESBL-Kp BSI at the neonatal care unit of Elmeki Hospital, Bejaia, Algeria. Methodology: After isolation, identification, and antibiotic susceptibility testing, the ESBL-Kp strains were characterized by whole genome sequencing. The genomes were then analyzed using bioinformatic tools to determine the resistome, virulome, and phylogenetic relatedness. Results: From September 2019 to May 2020, 27 (8.2%) out of 328 neonates were infected by ESBL-Kp strains. These strains displayed a multidrug-resistant phenotype, and on further investigation, were found to carry an array of antibiotic resistance genes. All ESBL-Kp strains harbored the bla_CTX-M-15 gene. Using in silico multilocus sequence typing analysis, six sequence types (STs) were detected with ST268 being the most frequent (56%, n = 15) indicating a local outbreak, confirmed by single nucleotide polymorphism analysis. The yersiniabactin and colibactin gene clusters were identified in six and two ESBL-Kp strains, respectively. Conclusion: This study showed a high prevalence of CTX-M-15-producing K. pneumoniae strains coharboring different antibiotic resistance mechanisms from neonatal BSIs in Algeria. Screening of health care personnel and mothers for ESBL carriage before delivery, isolation of carriers, barrier precautions, antimicrobial usage, and control of hygiene are needed to prevent the dissemination of these pathogens.

Characterisation of and risk factors for extended-spectrum β-lactamase producing Enterobacterales (ESBL-E) in an equine hospital with a special reference to an outbreak caused by Klebsiella pneumoniae ST307:CTX-M-1

Background

Extended-spectrum β-lactamase producing Enterobacterales (ESBL-E) are important causative agents for infections in humans and animals. At the Equine Veterinary Teaching Hospital of the University of Helsinki, the first infections caused by ESBL-E were observed at the end of 2011 leading to enhanced infection surveillance. Contact patients were screened for ESBL-E by culturing infection sites and rectal screening. This study was focused on describing the epidemiology and microbiological characteristics of ESBL-E from equine patients of the EVTH during 2011–2014, and analysing putative risk factors for being positive for ESBL-E during an outbreak of Klebsiella pneumoniae ST307.

Results

The number of ESBL-E isolations increased through 2012–2013 culminating in an outbreak of multi-drug resistant K. pneumoniae ST307:bla_CTX-M-1:bla_TEM:bla_SHV during 04–08/2013. During 10/2011–05/2014, altogether 139 ESBL-E isolates were found from 96 horses. Of these, 26 were from infection-site specimens and 113 from rectal-screening swabs. A total of 118 ESBL-E isolates from horses were available for further study, the most numerous being K. pneumoniae (n = 44), Escherichia coli (n = 31) and Enterobacter cloacae (n = 31). Hospital environmental specimens (N = 47) yielded six isolates of ESBL-E. Two identical E. cloacae isolates originating from an operating theatre and a recovery room had identical or highly similar PFGE fingerprint profiles as five horse isolates. In the multivariable analysis, mare–foal pairs (OR 4.71, 95% CI 1.57–14.19, P = 0.006), length of hospitalisation (OR 1.62, 95% CI 1.28–2.06, P < 0.001) and passing of a nasogastric tube (OR 2.86, 95% CI 1.03–7.95, P = 0.044) were associated with being positive for ESBL-E during the K. pneumoniae outbreak.

Conclusions

The occurrence of an outbreak caused by a pathogenic ESBL-producing K. pneumoniae ST307 strain highlights the importance of epidemiological surveillance of ESBL-E in veterinary hospitals. Limiting the length of hospitalisation for equine patients may reduce the risk of spread of ESBL-E. It is also important to acknowledge the importance of nasogastric tubing as a potential source of acquiring ESBL-E. As ESBL-E were also found in stomach drench pumps used with nasogastric tubes, veterinary practices should pay close attention to appropriate equipment cleaning procedures and disinfection practices.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13028-022-00621-6.

Colonisation with extended spectrum beta-lactamase-producing and carbapenem-resistant Enterobacterales in children admitted to a paediatric referral hospital in South Africa

INTRODUCTION

There are few studies describing colonisation with extended spectrum beta-lactamase-producing Enterobacterales (ESBL-PE) and carbapenem-resistant Enterobacterales (CRE) among children in sub-Saharan Africa. Colonisation often precedes infection and multi-drug-resistant Enterobacterales are important causes of invasive infection.

METHODS

In this prospective cross-sectional study, conducted between April and June 2017, 200 children in a tertiary academic hospital were screened by rectal swab for EBSL-PE and CRE. The resistance-conferring genes were identified using polymerase chain reaction technology. Risk factors for colonisation were also evaluated.

RESULTS

Overall, 48% (96/200) of the children were colonised with at least one ESBL-PE, 8.3% (8/96) of these with 2 ESBL-PE, and one other child was colonised with a CRE (0.5% (1/200)). Common colonising ESBL-PE were Klebsiella pneumoniae (62.5%, 65/104) and Escherichia coli (34.6%, 36/104). The most frequent ESBL-conferring gene was blaCTX-M in 95% (76/80) of the isolates. No resistance- conferring gene was identified in the CRE isolate (Enterobacter cloacae). Most of the Klebsiella pneumoniae isolates were susceptible to piperacillin/tazobactam (86.2%) and amikacin (63.9%). Similarly, 94.4% and 97.2% of the Escherichia coli isolates were susceptible to piperacillin/tazobactam and amikacin, respectively. Hospitalisation for more than 7 days before study enrolment was associated with ESBL-PE colonisation.

CONCLUSION

Approximately half of the hospitalised children in this study were colonised with ESBL-PE. This highlights the need for improved infection prevention and control practices to limit the dissemination of these microorganisms.

Changing trend in bacterial etiology and antibiotic resistance in sepsis of intramural neonates at a tertiary care hospital

Background:

Septicemia is an important cause of neonatal morbidity and mortality. However, organized data on causative organisms and their resistant pattern are scanty from developing countries. The changing trend in causative organisms and their antibiotic resistance is yet to be documented in India. The present study examines the trends in bacterial profile and antibiotic resistance of the organisms causing sepsis in hospitalized neonates.

Materials and Methods:

A retrospective laboratory-based analysis of blood cultures obtained from Neonatal Intensive Care Unit of a tertiary care hospital in New Delhi was done for the period of 1999–2014, divided into five phases.

Results:

A total of 4700 isolates were considered. Over time, Gram-negative organisms have replaced Gram-positives as frequent isolates. Initially, there was predominance of Klebsiella pneumoniae, then of Staphylococcus aureus which recently has been changed with coagulase negative-Staphylococcus and Acinetobacter. Growing resistance against the first and second line of drugs has been noted, including methicillin-resistant S. aureus and vancomycin-resistant Enterococcus.

Conclusion:

The etiological profile of neonatal sepsis has changed tremendously in the past 15 years. High resistance against common drugs necessitates continued surveillance and review of empirical antibiotic policy for neonatal sepsis. These steps are important to effectively curtail the surge of further antibiotic resistance.

Available evidence of antibiotic resistance from extended-spectrum β-lactamase-producing Enterobacteriaceae in paediatric patients in 20 countries: a systematic review and meta-analysis

OBJECTIVE

To make a systematic review of risk factors, outcomes and prevalence of extended-spectrum β-lactamase-associated infection in children and young adults in South-East Asia and the Western Pacific.

METHODS

Up to June 2018 we searched online databases for published studies of infection with extended-spectrum β-lactamase-producing Enterobacteriaceae in individuals aged 0-21 years. We included case-control, cohort, cross-sectional and observational studies reporting patients positive and negative for these organisms. For the meta-analysis we used random-effects modelling of risk factors and outcomes for infection, and meta-regression for analysis of subgroups. We mapped the prevalence of these infections in 20 countries and areas using available surveillance data.

FINDINGS

Of 6665 articles scanned, we included 40 studies from 11 countries and areas in the meta-analysis. The pooled studies included 2411 samples testing positive and 2874 negative. A higher risk of infection with extended-spectrum β-lactamase-producing bacteria was associated with previous hospital care, notably intensive care unit stays (pooled odds ratio, OR: 6.5; 95% confidence interval, CI: 3.04 to 13.73); antibiotic exposure (OR: 4.8; 95% CI: 2.25 to 10.27); and certain co-existing conditions. Empirical antibiotic therapy was protective against infection (OR: 0.29; 95% CI: 0.11 to 0.79). Infected patients had longer hospital stays (26 days; 95% CI: 12.81 to 38.89) and higher risk of death (OR: 3.2; 95% CI: 1.82 to 5.80). The population prevalence of infection was high in these regions and surveillance data for children were scarce.

CONCLUSION

Antibiotic stewardship policies to prevent infection and encourage appropriate treatment are needed in South-East Asia and the Western Pacific.

Molecular characterization, antimicrobial resistance and clinico-bioinformatics approaches to address the problem of extended-spectrum β-lactamase-producing Escherichia coli in western Saudi Arabia

The goal of this study was to genotypically characterize extended-spectrum β-lactamase-producing Escherichia coli isolates from the western region of Saudi Arabia and to identify active antibiotics against these isolates using phenotypic and molecular modeling. In total, 211 ESBL-producing E. coli isolates recovered from heterogeneous clinical specimens were identified by MALDI-TOF. Thirty-two sequence types (STs) were identified from a multilocus sequence typing (MLST) analysis of ESBL-producing E. coli, including a novel ST (ST8162). The most common ST in the Saudi and expatriate population was ST131, followed by ST38. All the isolates were multidrug resistant (MDR), and >95% of the isolates were resistant to third-generation (ceftriaxone and ceftazidime) and fourth-generation (cefepime) cephalosporins. The ESBL-positive E. coli isolates primarily harbored the bla_CTX-M and bla_TEM genes. No resistance was observed against the carbapenem antibiotic group. All the ESBL-producing E. coli isolates were observed to be susceptible to a ceftazidime/avibactam combination. Molecular interaction analyses of the docked complexes revealed the amino acid residues crucial for the binding of antibiotics and inhibitors to the modeled CTX-M-15 enzyme. Importantly, avibactam displayed the most robust interaction with CTX-M-15 among the tested inhibitors in the docked state (∆G = −6.6 kcal/mol). The binding free energy values for clavulanate, tazobactam and sulbactam were determined to be −5.7, −5.9 and −5.2 kcal/mol, respectively. Overall, the study concludes that ‘ceftazidime along with avibactam’ should be carefully used as a treatment option against only carbapenem-resistant MDR ESBL-producing E. coli in this region.

Acquisition of extended spectrum beta-lactamase-producing enterobacteriaceae in neonates: A community based cohort in Madagascar

In low and middle income countries (LMICs), where the burden of neonatal sepsis is the highest, the spread of extended spectrum beta-lactamase-producing enterobacteriaceae (ESBL-PE) in the community, potentially contributing to the neonatal mortality, is a public health concern. Data regarding the acquisition of ESBL-PE during the neonatal period are scarce. The routes of transmission are not well defined and particularly the possible key role played by pregnant women. This study aimed to understand the neonatal acquisition of ESBL-PE in the community in Madagascar. The study was conducted in urban and semi-rural areas. Newborns were included at birth and followed-up during their first month of life. Maternal stool samples at delivery and six stool samples in each infant were collected to screen for ESBL-PE. A Cox proportional hazards model was performed to identify factors associated with the first ESBL-PE acquisition. The incidence rate of ESBL-PE acquisition was 10.4 cases/1000 newborn-days [95% CI: 8.0–13.4 cases per 1000 newborn-days]. Of the 83 ESBL-PE isolates identified, Escherichia coli was the most frequent species (n = 28, 34.1%), followed by Klebsiella pneumoniae (n = 20, 24.4%). Cox multivariate analysis showed that independent risk factors for ESBL-PE acquisition were low birth weight (adjusted Hazard-ratio (aHR) = 2.7, 95% CI [1.2; 5.9]), cesarean-section, (aHR = 3.4, 95% CI [1.7; 7.1]) and maternal use of antibiotics at delivery (aHR = 2.2, 95% CI [1.1; 4.5]). Our results confirm that mothers play a significant role in the neonatal acquisition of ESBL-PE. In LMICs, public health interventions during pregnancy should be reinforced to avoid unnecessary caesarean section, unnecessary antibiotic use at delivery and low birth weight newborns.

Risk factors for infection and/or colonisation with extended-spectrum β-lactamase-producing bacteria in the neonatal intensive care unit: a meta-analysis

Extended-spectrum β-lactamase (ESBL)-producing bacteria are an important cause of healthcare-associated infections in the neonatal intensive care unit (NICU). The aim of this meta-analysis was to identify risk factors associated with infection and/or colonisation with ESBL-producing bacteria in the NICU. Electronic databases were searched for relevant studies published from 1 January 2000 to 1 July 2016. The literature was screened and data were extracted according to the inclusion and exclusion criteria. The Z-test was used to calculate the pooled odds ratio (OR) of the risk factors. ORs and their 95% confidence intervals were used to determine the significance of the risk. A total of 14 studies, including 746 cases and 1257 controls, were identified. Thirteen risk factors were determined to be related to infection and/or colonisation with ESBL-producing bacteria in the NICU: birthweight [standardised mean difference (SMD) = 1.17]; gestational age (SMD = 1.36); Caesarean delivery (OR = 1.76); parenteral nutrition (OR = 7.51); length of stay in the NICU (SMD = 0.72); mechanical ventilation (OR = 4.8); central venous catheter use (OR = 2.85); continuous positive airway pressure (OR = 5.0); endotracheal intubation (OR = 2.82); malformations (OR = 2.89); previous antibiotic use (OR = 6.72); ampicillin/gentamicin (OR = 2.31); and cephalosporins (OR = 6.0). This study identified risk factors for infection and/or colonisation with ESBL-producing bacteria in the NICU, which may provide a theoretical basis for preventive measures and targeted interventions.

Prevalence and Risk Factors associated with Extended Spectrum Beta Lactamase Producing Escherichia coli and Klebsiella pneumoniae Isolates in Hospitalized Patients in Kashan (Iran)

INTRODUCTION

Production of extended spectrum beta lactamase (ESBL) is an important mechanism of antimicrobial resistance in Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) isolates. This study was performed to determine the prevalence and risk factors associated with ESBL producing strains of E. coli and K. pneumoniae.

METHODS

In this cross-sectional study, 250 strains (134 E. coli and 116 K. pneumoniae) were obtained, and ESBL producing isolates were detected by the combination disk test in Shahid Beheshti Hospital in Kashan, Iran, from February 2012 to June 2013. Antimicrobial resistance was screened by the disk diffusion method and was confirmed by E-test. Furthermore, risk factors of ESBL producing E. coli and K. pneumoniae microorganisms were determined. Data were analyzed by SPSS version 16, using descriptive statistics, chi-squared, independent-samples t-test, and logistic regression analysis.

RESULTS

One hundred and two (40.8%) of all strains were ESBL producers, of which 54 (52.9%) were E. coli and 48 (47.1%) were K. pneumoniae (p = 0.86). Furthermore, 40.3% of E. coli and 41.4% of K. pneumoniae isolates were ESBL producers (p = 0.86). The most antimicrobial resistance was to ampicillin, and no imipenem resistance was detected. Risk factors for ESBL producing E. coli included admission duration exceeding 7 days (p = 0.011) and antibiotic use in the last month (p < 0.001), and the associated risk factor for ESBL producing K. pneumoniae was antibiotic use during the recent month (p = 0.002).

CONCLUSION

This study identified a relatively high prevalence of ESBL production among E. coli and K. pneumoniae strains. Furthermore, anti-bimicrobial use and admission duration were risk factors for ESBL producing isolates. Therefore, more comprehensive investigations are needed for the development of new strategies to control the dissemination of these microbes.

Isolation of MRSA, ESBL and AmpC - β -lactamases from Neonatal Sepsis at a Tertiary Care Hospital

BACKGROUND AND OBJECTIVES

The emergence of methicillin resistant Staphylococcus aureus (MRSA) and extended spectrum β-lactamases (ESBLs) in neonatal intensive care unit patients is increasing. This study aims to find out the bacteriological profile in neonatal sepsis and study their antimicrobial susceptibility pattern including detection of MRSA and ESBLs.

MATERIALS AND METHODS

This study was conducted for a period of one and a half years from January 2010 to June 2011 in a tertiary care hospital in Chennai. A total of 182 blood samples were collected using sterile precautions. They were processed following standard laboratory protocol. Antibiogram was done using appropriate antibiotics by Kirby-Bauer disc diffusion method. Isolated Staphylococcus aureus were tested for methicillin resistance using Cefoxitin disc (30μg), ESBL was detected using combined disc method, MIC reduction and Polymerase chain reaction, metallobetalactamases using EDTA and Amp-C beta lactamases using AmpC disc test. C-reactive protein (CRP) was estimated for all the cases.

RESULTS

Out of the 182 cases, 110 (60.4%) were culture positive. Fifty five (63.9 %) of early onset sepsis cases had Gram negative bacteria (GNB) and 19 (79.1%) of late onset sepsis cases had Gram positive bacteria. Out of the total pathogens, 31 (28.1%) were Klebsiella pneumoniae and 30 (27%) were Staphylococcus aureus. 17 (56.6 %) of Staphylococcus aureus were found to be MRSA and they were 100% sensitive to Vancomycin. 33 (67.3%) of Enterobacteriaceae were ESBL producers. ESBL isolates were 100% sensitive to Imipenem. Three (6.1%) of Enterobacteriaceae were AmpC producers and 3 (27.2%) of Pseudomonas aeruginosa were MBL producers. CRP was positive in 99 (54.3%) cases, out of which 94 (94.9%) were culture positive.

CONCLUSION

Klebsiella spp. and Staphylococcus aureus were the commonest bacteria causing neonatal sepsis in this centre. Multidrug resistance among the isolates was common. Early diagnosis and institution of specific antibiotics after studying the sensitivity pattern will help in reducing neonatal morbidity and mortality and prevent emergence of drug resistant strains.

Prevalence of IncI1-Iγ and IncFIA-FIB type plasmids in extended-spectrum β-lactamase-producing Klebsiella pneumoniae strains isolated from the NICU of a North Indian hospital

We studied the molecular mechanism of resistance in extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae isolated from a neonatal intensive care unit (NICU) of one of the hospitals in North India. A total of 3000 clinical samples were collected from a NICU (January 2009 to February 2011), of which 523 strains were K. pneumoniae positive and 262 of them were ESBL-producing K. pneumoniae strains. All of the ESBL-producing clinical isolates were susceptible to carbapenems. However, the majority of the clinical isolates (30–96 %) were resistant to a wide range of antibiotics including antibiotic/inhibitor combinations. The MIC values confirmed that these isolates were highly resistant to cephalosporins and aztreonam. In the 262 ESBL-producing K. pneumoniae isolates, 15 different enterobacterial repetitive intergenic consensus (ERIC)-PCR-typed phylogenetic groups were identified and reconfirmed by PFGE. Characterization of plasmids from each representative member of these phylogenetic groups revealed the presence of three plasmids of different sizes. Conjugation experiments confirmed the presence of different resistance markers only on the 154 kb plasmid. PCR amplification and sequence analysis revealed that bla CTX-M-3, bla TEM-1, bla SHV-1, bla OXA-1 and armA were the predominant resistance markers. Plasmid-replicon typing showed that IncI1-Iγ and IncFIA-FIB types are the most prevalent. This study shows the co-existence of multiple ESBL-encoding genes and their polyclonal dissemination among K. pneumoniae clinical isolates in the NICU of a North Indian hospital.

Risk factors for acquisition of extended spectrum beta lactamase producing Escherichia coli and Klebsiella pneumoniae in North-Indian hospitals

Multidrug resistance and production of extended spectrum β-lactamases (ESBLs) by enteric gram negative rods in hospitals and community continue to be a matter of scientific concern. This retrospective study was executed to assess the prevalence of ESBL-producing Escherichia coli and Klebsiella pneumoniae at two North Indian hospitals and to determine the risk factors associated with the acquisition of these organisms. A total of 346 bacterial isolates were obtained. Of these, 48.27% (n = 167) were confirmed to be ESBL producers while 51.73% (n = 179) were non ESBL-producers. Among the ESBL producers, 55.69% (n = 93) were E. coli and 44.31% (n = 74) were K. pneumoniae. ESBL producing isolates showed co-resistance to multitude of antibiotics tested. Length of hospital stay (>3 days) and previous exposure to antibiotics were found as significant risk factors (p = 0.01 and 0.02) associated with the acquisition of ESBL-producing E. coli and K. pneumoniae isolates. Imipenem and meropenem can be suggested as drugs of choice in our study.

High proportion of intestinal colonization with successful epidemic clones of ESBL-producing Enterobacteriaceae in a neonatal intensive care unit in Ecuador

Background and Aims

Neonatal infections caused by Extended-spectrum beta-lactamase (ESBL)-producing bacteria are associated with increased morbidity and mortality. No data are available on neonatal colonization with ESBL-producing bacteria in Ecuador. The aim of this study was to determine the proportion of intestinal colonization with ESBL-producing Enterobacteriaceae, their resistance pattern and risk factors of colonization in a neonatal intensive care unit in Ecuador.

Methods

During a three month period, stool specimens were collected every two weeks from hospitalized neonates. Species identification and susceptibility testing were performed with Vitek2, epidemiologic typing with automated repetitive PCR. Associations between groups were analyzed using the Pearson _X² test and Fisher exact test. A forward step logistic regression model identified significant predictors for colonization.

Results

Fifty-six percent of the neonates were colonized with ESBL-producing Enterobacteriaceae. Length of stay longer than 20 days and enteral feeding with a combination of breastfeeding and formula feeding were significantly associated with ESBL-colonization. The strains found were E. coli (EC, 89%) and K. pneumoniae (KP, 11%) and epidemiological typing divided these isolates in two major clusters. All EC and KP had bla_CTX-M group 1 except for a unique EC isolate that had bla_CTX-M group 9. Multi-locus sequence typing performed on the K. pneumoniae strains showed that the strains belonged to ST855 and ST897. The two detected STs belong to two different epidemic clonal complexes (CC), CC11 and CC14, which previously have been associated with dissemination of carbapenemases. None of the E. coli strains belonged to the epidemic ST 131 clone.

Conclusions

More than half of the neonates were colonized with ESBL-producing Enterobacteriaceae where the main risk factor for colonization was length of hospital stay. Two of the isolated clones were epidemic and known to disseminate carbapenemases. The results underline the necessity for improved surveillance and infection control in this context.

Frequency and characteristics of infections caused by extended-spectrum beta-lactamase-producing organisms in neonates: a prospective cohort study

This prospective cohort study was conducted to determine the frequency of infections caused by extended-spectrum beta-lactamase- (ESBL-) producing organisms, various bacteria producing ESBL, antibiotic susceptibility of these organisms, and the risk factors associated with these infections in a neonatal intensive care unit in a tertiary care hospital in North India. Of the 150 neonates enrolled in the study, 47 culture-positive neonates were included in the study cohort and were divided into two groups: ESBL-positive (8 neonates) and ESBL-negative (39 neonates) cohorts. Various organisms were isolated from 72 culture samples in these 47 neonates. Of these, 10 culture samples grew ESBL-positive organisms and 62 samples grew ESBL-negative organisms. The frequency of ESBL-producing organisms was found to be 5.3%. ESBL infection incidence densities were found to be 3.4 per 1000 patient-days. Klebsiella (60%) was the most common organism producing ESBL followed by Escherichia coli (30%) and Pseudomonas (10%). Eighty percent of the ESBL-producing organisms were sensitive to piperacillin-tazobactam. Risk factors found significant by univariate analysis (P < 0.05) were preterm, low birthweight, perinatal asphyxia, respiratory distress syndrome, anaemia, metabolic acidosis, prolonged mechanical ventilation (>7 days), length of hospitalization, length of level 3 stay, prior antibiotic use, central venous catheter duration, peripherally inserted central venous catheter duration, and total parenteral nutrition duration. Factors that retained significance in the logistic regression model were duration of hospital stay (adjusted OR: 0.958, CI: 0.920–0.997, and P value = 0.037) and gestational age (adjusted OR: 1.39, CI: 1.037–1.865, and P value = 0.028). There was no significant difference in the mortality between the two groups.

First outbreak of extended-spectrum β-lactamase-producing Klebsiella pneumoniae in a Norwegian neonatal intensive care unit; associated with contaminated breast milk and resolved by strict cohorting

Neonatal intensive care units (NICUs) are vulnerable to nosocomial outbreaks caused by multiresistant Enterobacteriaceae, but no reports of NICU outbreaks of extended-spectrum β-lactamase (ESBL) producing Klebsiella pneumoniae have previously been published from countries with a low level of antimicrobial resistance such as the Scandinavian countries. We describe a clonal outbreak of CTX-M-15 -producing Klebsiella pneumoniae affecting 58 infants in the neonatal intensive care unit at Stavanger University Hospital, Norway, during a period of 4 months, 2008-2009. The clone spread widely and rapidly in the NICU, and extensive interventions were required to terminate the outbreak. In contrast to previous outbreaks, only one infant acquired a systemic infection caused by the outbreak strain, probably due to a favourable epidemic strain lacking the most common virulence factors. A probable index case was identified, due to multiple positive breast milk samples collected from the infant's mother before and after the infant's transfer from another hospital. Breast milk samples from 3/18 (17%) mothers of colonized infants were positive for ESBL-producing K. pneumoniae. Vertical transmission of ESBL-producing bacteria has been shown previously,&#146;but the possibility of transmission of ESBL-producing K. pneumoniae through expressed breast milk is reported here for the first time. The increasing occurrence of ESBL-producing&#146;Enterobacteriaceae should therefore encourage changes in diagnostic routines for bacterial screening of breast milk.

Prevalence of plasmid mediated bla(TEM-1) and bla(CTX-M-15) type extended spectrum beta-lactamases in patients with sepsis

OBJECTIVE

To characterize the bacterial pathogens in patients having gram negative septicaemia. Further, to evaluate the antimicrobial resistance and underlying molecular mechanisms in these strains.

METHODS

A total number of 70 cases of gram negative sepsis were included in this prospective, open labeled, observational study. Standard methods for isolation and identification of bacteria were used. Antimicrobial susceptibility and ESBL testing was performed by the standard disc diffusion method. PCR amplification was performed to identify bla(CTX-M), bla(SHV) and bla(TEM) type ESBLs. Conjugation experiments were performed to show resistant marker transfer.

RESULTS

The most prevalent isolates Escherichia coli (E. coli) 58.6%, Klebsiella Spp. 32.9% and Pseudomonas 8.6%, were resistant to most of the antimicrobials including cefazolin, ceftriaxone, cefuroxime, ampicillin and co-trimoxazole but sensitive to imipenem and meropenem. ESBL and MBL production was seen 7.3% and 12.2% of E. coli isolates respectively. Three isoaltes were found to have bla(CTX-M-15) and two of them also showed bla(TEM-1) type enxyme. Whereas, none of them showed bla(SHV). Conjugation experiments using J-53 cells confirmed these resistant markers as plasmid mediated.

CONCLUSIONS

This work highlights the molecular epidemiology of escalating antimicrobial resistance and likely switch over of bla(CTX-M-15) type extended spectrum beta-lactamases by bla(TEM) type ESBLs in India. Further, the antimicrobial resistance by horizontal gene transfer was predominant among Enterobacteraceae in the community setting.

Secular trends in antibiotic use among neonates: 2001-2008

BACKGROUND

Few data exist on time trends of antibiotic consumption among neonates.

OBJECTIVES

To assess secular trends in antibiotic consumption in the context of an antibiotic policy and the effect of antibiotic use on the development of antimicrobial resistance and outcome among neonates in a single center.

METHODS

We performed a prospective cohort study between 2001 and 2008 to monitor antibiotic consumption among neonates. In parallel, we initiated a policy to shorten antibiotic therapy for clinical sepsis and for infections caused by coagulase-negative staphylococci and to discontinue preemptive treatment when blood cultures were negative. Time trend analyses for antibiotic use and mortality were performed.

RESULTS

In total, 1096 of 4075 neonates (26.7%) received 1281 courses of antibiotic treatment. Overall, days of therapy were 360 per 1000 patient-days. Days of therapy per 1000 patient-days decreased yearly by 2.8% (P < 0.001). Antibiotic-days to treat infections decreased yearly by 6.5% (P = 0.01) while antibiotic-days for preemptive treatment increased by 3.4% per year (P = 0.03). Mean treatment duration for confirmed infections decreased by 2.9% per year (P < 0.001). No significant upward trend was observed for infection-associated mortality. Of 271 detected healthcare-associated infections, 156 (57.6%) were microbiologically documented. The most frequent pathogens were coagulase-negative staphylococci (48.5%) followed by Escherichia coli (13.5%) and enterococci (9.4%). Rates for extended-spectrum beta-lactamase-producing microorganisms and methicillin-resistant Staphylococcus aureus remained low.

CONCLUSIONS

Shortening antibiotic therapy and reducing preemptive treatment resulted in a moderate reduction of antibiotic use in the neonatal intensive care unit and did not increase mortality.

Infected foot ulcers in male and female diabetic patients: a clinico-bioinformative study

BACKGROUND

The study aimed at (i) characterizing the mode of transmission of bla(CTX-M) and bla(TEM-1) among extended-spectrum-beta-lactamase (ESBL)-producing Escherichia coli strains isolated from infected diabetic foot ulcers, and (ii) identifying the risk factors for "sex-associated multidrug resistant Gram-negative bacterial (MDRGNB)-infection status" of the ulcers.

METHODS

Seventy-seven diabetic patients having clinically infected foot ulcers were studied in a consecutive series. The E. coli strains isolated from the ulcers were screened for bla(CTX-M), bla(TEM-1), armA, rmtA and rmtB during the 2-year study-period. PCR amplified bla(CTX-M) genes were cloned and sequenced. Enterobacterial repetitive intergenic consensus (ERIC)-PCR was used for the analysis of genetic relatedness of the ESBL-producers. Risk factors for "sex-associated MDRGNB-infection status" of ulcers were assessed. Modeling was performed using Swiss-Model-Server and verified by Procheck and verify3D programmes. Discovery Studio2.0 (Accelrys) was used to prepare Ramachandran plots. Z-scores were calculated using 'WHAT IF'-package. Docking of cefotaxime with modeled CTX-M-15 enzyme was performed using Hex5.1.

RESULTS

Among 51 E. coli isolates, 14 (27.5%) ESBL-producers were identified. Only 7 Class1 integrons, 2 bla(CTX-M-15), and 1 bla(TEM-1) were detected. Ceftazidime and cefotaxime resistance markers were present on the plasmidic DNA of both the bla(CTX-M-15) positive strains and were transmissible through conjugation. The residues Asn132, Glu166, Pro167, Val172, Lys234 and Thr235 of CTX-M-15 were found to make important contacts with cefotaxime in the docked-complex. Multivariate analysis proved 'Glycemic control at discharge' as the single independent risk factor.

CONCLUSIONS

Male diabetic patients with MDRGNB-infected foot ulcers have poor glycemic control and hence they might have higher mortality rates compared to their female counterparts. Plasmid-mediated conjugal transfer, albeit at a low frequency might be the possible mechanism of transfer of bla(CTX-M-15) resistance marker in the present setting. Since the docking results proved that the amino acid residues Asn132, Glu166, Pro167, Val172, Lys234 and Thr235 of CTX-M-15 (enzyme) make important contacts with cefotaxime (drug) in the 'enzyme-drug complex', researchers are expected to duly utilize this information for designing more potent and versatile CTX-M-inhibitors.