Colonisation by extended-spectrum β-lactamase-producing Klebsiella spp. in a paediatric intensive care unit

Prevalence of extended spectrum beta lactamase and molecular detection of blaTEM, blaSHV and blaCTX-M genotypes among Gram negative bacilli isolates from pediatric patient population in Gaza strip

BACKGROUND

Extended-spectrum β lactamases (ESBLs), have the ability to hydrolyze and cause resistance to various types of the β-lactam antibiotics, including the extended-spectrum (or third-generation) cephalosporins (e.g., cefotaxime, ceftriaxone, ceftazidime) and monobactams (e.g., aztreonam). ESBL-producing Gram negative bacteria is still posing significant therapeutic challenges.

OBJECTIVES

To assess the prevalence and molecular characteristics of ESBL producing Gram negative bacilli, isolated from a cohort of pediatric patients in Gaza hospitals.

METHODS

A total of 322 isolates of Gram-negative bacilli were collected from four referral pediatric hospitals in Gaza, namely: Al-Nasr, Al-Rantisi, Al-Durra and Beit Hanoun hospitals. These isolates were tested for ESBL production using the double disk synergy and CHROMagar phenotypic methods. Molecular characterization of the ESBL producing strains was performed using PCR targeting the CTX-M, TEM and SHV genes. Antibiotic profile was done using Kirby Bauer method according to Clinical and Laboratory Standard Institute.

RESULTS

Out of 322 isolates tested by phenotypic methods, 166 (51.6%) were ESBL positive. The prevalence of ESBL production in Al-Nasr, Al-Rantisi, Al-Durra and Beit Hanoun hospitals was 54%, 52.5%, 45.5% and 52.8% respectively. The prevalence of ESBL production among Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter spp., Proteus mirabilis, Enterobacter spp., Citrobacter spp., and Serratia marcescens is 55.3%, 63.4%, 17.8%, 57.1%, 33.3%, 28.5%, 38.4%, and 4% respectively. ESBL production among urine, pus, blood, CSF and sputum was 53.3%, 55.2%, 47.4%, 33.3%, and 25% respectively. Out of the 322 isolates, 144 were screened for CTX-M, TEM and SHV production. Using PCR, 85 (59%) had at least one gene. The prevalence rate of CTX-M, TEM and SHV genes was 60%, 57.6%, and 38.3% respectively. Meropenem and amikacin were highest rates of susceptibility antibiotics against ESBLs producers (83.1% and 82.5% respectively), while the least effective antibiotics were amoxicillin (3.1%) and cephalexin (13.9%). Moreover, ESBLs producers showed high resistance rate to cefotaxime, ceftriaxone and ceftazidime (79.5%, 78.9% and 79.5% respectively).

CONCLUSION

Our results show high prevalence of ESBL production among Gram negative bacilli isolated from children in different pediatric hospitals in Gaza strip. A substantial level of resistance to first and second generation cephalosporins was also observed. This ascertains the need for a rational antibiotic prescription and consumption policy.

Intense intestinal carriage and subsequent acquisition of multidrug-resistant enterobacteria in neonatal intensive care unit in Morocco

This study was conducted in order to know the colonization rate of MDR enterobacteria in neonates during their hospitalization in neonatal intensive care unit (NICU). Furthermore, we investigated risk factors for potential colonization and molecular epidemiology of isolated resistant bacteria. This prospective study was carried out in the neonatology and intensive care unit department of the University Hospital of Fez (Morocco) from February 2013 to July 2015. All consecutive admitted newborns were screened for intestinal and nasal carriage of MDR enterobacteria at admission of the babies and during the hospitalization. During the study period, a total of 641 Enterobacteriaceae were isolated and Klebsiella pneumoniae was the predominated bacteria. Bacterial identification and antibiograms were performed according to the international standards. On admission, 455 newborns were screened. A median age of these newborns was 1 day with an extended 147 days and their average weight was 2612 ± 1023 grams. 22.4% of neonates were found colonized by an ESBL producing Enterobacteriaceae (ESBL-E), 8.7% by a carbapenemases producing Enterobacteriaceae (CPE). During hospitalization, 207 of newborns were included in the acquisition study. 59.4% of newborns acquired an ESBL-E during their stay, 12.5% has acquired CPE. The blaCTXM-15 gene was the most frequently detected (81.2%) among ESBL-E. While, all CPE has expressed the blaOXA-48 gene exclusively. Two risk factors have been significantly associated with MDR enterobacteria colonization at admission which are newborns admission from maternity of the university hospital (95% CI, 1.859-5.129, P = 0.000) and neurological distress (95% CI, 1.038 to 4.694, P = 0.040). During hospitalization, the none risk factor was significantly associated with the carriage of MDR-E. The high rate of colonization, the MDR enterobacteria and the resistance genes found represent good indicator of cross-transmission in the NICU. An active strategy to control the spread of MDR enterobacteria should be applied.

Suspicion of respiratory tract infection with multidrug-resistant Enterobacteriaceae: epidemiology and risk factors from a Paediatric Intensive Care Unit

BACKGROUND

Multidrug-resistant (MDR) infections are a serious concern for children admitted to the Paediatric Intensive Care Unit (PICU). Tracheal colonization with MDR Enterobacteriaceae predisposes to respiratory infection, but underlying risk factors are poorly understood. This study aims to determine the incidence of children with suspected infection during mechanical ventilation and analyses risk factors for the finding of MDR Enterobacteriaceae in tracheal aspirates.

METHODS

A retrospective single-centre analysis of Enterobacteriaceae isolates from the lower respiratory tract of ventilated PICU patients from 2005 to 2014 was performed. Resistance status was determined and clinical records were reviewed for potential risk factors. A classification and regression tree (CRT) to predict risk factors for infection with MDR Enterobacteriaceae was employed. The model was validated by simple and multivariable logistic regression.

RESULTS

One hundred sixty-seven Enterobacteriaceae isolates in 123 children were identified. The most frequent isolates were Enterobacter spp., Klebsiella spp. and E.coli. Among these, 116 (69%) isolates were susceptible and 51 (31%) were MDR. In the CRT analysis, antibiotic exposure for ≥ 7 days and presence of gastrointestinal comorbidity were the most relevant predictors for an MDR isolate. Antibiotic exposure for ≥ 7 days was confirmed as a significant risk factor for infection with MDR Enterobacteriaceae by a multivariable logistic regression model.

CONCLUSIONS

This study shows that critically-ill children with tracheal Enterobacteriaceae infection are at risk of carrying MDR isolates. Prior use of antibiotics for ≥ 7 days significantly increased the risk of finding MDR organisms in ventilated PICU patients with suspected infection. Our results imply that early identification of patients at risk, rapid microbiological diagnostics and tailored antibiotic therapy are essential to improve management of critically ill children infected with Enterobacteriaceae.

Colonization with third-generation cephalosporin-resistant Enterobacteriaceae on hospital admission: prevalence and risk factors

OBJECTIVES

The objectives of this study were to prospectively assess the rectal carriage rate of third-generation cephalosporin-resistant Enterobacteriaceae (3GCREB) in non-ICU patients on hospital admission and to investigate resistance mechanisms and risk factors for carriage.

METHODS

Adult patients were screened for 3GCREB carriage at six German tertiary care hospitals in 2014 using rectal swabs or stool samples. 3GCREB isolates were characterized by phenotypic and molecular methods. Each patient answered a questionnaire about potential risk factors for colonization with MDR organisms (MDROs). Univariable and multivariable risk factor analyses were performed to identify factors associated with 3GCREB carriage.

RESULTS

Of 4376 patients, 416 (9.5%) were 3GCREB carriers. Escherichia coli was the predominant species (79.1%). ESBLs of the CTX-M-1 group (67.3%) and the CTX-M-9 group (16.8%) were the most frequent β-lactamases. Five patients (0.11%) were colonized with carbapenemase-producing Enterobacteriaceae. The following risk factors were significantly associated with 3GCREB colonization in the multivariable analysis (P < 0.05): centre; previous MDRO colonization (OR = 2.12); antibiotic use within the previous 6 months (OR = 2.09); travel outside Europe (OR = 2.24); stay in a long-term care facility (OR = 1.33); and treatment of gastroesophageal reflux disease (GERD) (OR = 1.22).

CONCLUSIONS

To our knowledge, this is the largest admission prevalence study of 3GCREB in Europe. The observed prevalence of 9.5% 3GCREB carriage was higher than previously reported and differed significantly among centres. In addition to previously identified risk factors, the treatment of GERD proved to be an independent risk factor for 3GCREB colonization.

Prevalence of Extended Spectrum β-Lactamase and Antimicrobial Susceptibility Pattern of Clinical Isolates of Pseudomonas from Patients of Khyber Pakhtunkhwa, Pakistan

Majority of gram negative pathogenic bacteria are responsible for extended spectrum β-lactamases (ESBLs) production, which show resistance to some newer generation of antibiotics. The study was aimed at evaluating the prevalence of ESBL and antibiotic susceptibility pattern of Pseudomonas isolates collected during 2010 to 2014 from tertiary care hospitals of Peshawar, Pakistan. Out of 3450 samples, 334 Pseudomonas spp. isolates comprised of 232 indoor and 102 outdoor patients were obtained from different specimens and their susceptibility pattern was determined against 20 antibiotics. Antimicrobial susceptibility testing was carried out using the Kirby-Bauer agar diffusion method and ESBL production was detected by Synergy Disc Diffusion technique. The mean age group of the patients was 29.9 + 9.15 years. Meronem showed best activity (91.02%) from class carbapenem, β-lactam and β-lactamase inhibitors exhibited 69.16% activity, and doxycycline had a diminished activity (10.18%) to Pseudomonas spp. Outdoor isolates were more resistant than the indoor and during the course of the study the sensitivity rate of antibiotics was gradually reducing. ESBL production was observed in 44.32% while the remaining was non-ESBL. The moderate active antibiotics were amikacin (50.7%), SCF (51.4%), TZP (52.7%), and MXF (54.1%) among ESBL producing isolates. Lack of antibiotic policy, irrational uses (3GCs particularly), and the emergence of antibiotic resistant organisms in hospitals may be causes of high antibiotic resistance.

Extended spectrum β-lactamase producers among nosocomial Enterobacteriaceae in Latin America

To review the epidemiology of nosocomial extended spectrum β-lactamase-producing Enterobacteriaceae in Latin America, a systematic search of the biomedical literature (PubMed) was performed for articles published since 2005. Rates of nosocomial infections caused by extended spectrum β-lactamase-producing Enterobacteriaceae in Latin America have increased since 2005. Up to 32% of Escherichia coli and up to 58% of Klebsiella pneumoniae isolates are extended spectrum β-lactamase-positive, rates that are higher than in other world regions. From a region-wide perspective, 11–25% of E. coli isolates and 45–53% of K. pneumoniae isolates were nonsusceptible to third-generation cephalosporins. At the country level, there was a wide range in Enterobacteriaceae resistance rates to third-generation cephalosporins, with especially high rates of resistance to E. coli in Guatemala, Honduras, and Mexico, and high resistance rates to Klebsiella spp. in Argentina, Brazil, Chile, Guatemala, Honduras, and Paraguay. Susceptibility of extended spectrum β-lactamase-producing Enterobacteriaceae to cefepime, fluoroquinolones, ampicillin/sulbactam, aminoglycosides, and piperacillin/tazobactam has also been compromised, leaving the carbapenems, tigecycline, and colistin as the only antibiotics with >90% susceptibility rates. There is a steady increase in the prevalence and types of extended spectrum β-lactamases produced by Enterobacteriaceae isolates in Latin American hospitals (particularly CTX-Ms), suggesting endemic conditions overlaid by clonal outbreaks. Appropriate treatment decisions and infection control strategies informed by surveillance of regional and local susceptibilities and mechanisms of resistance are required to mitigate this major public health concern.

Risk factors associated with extended-spectrum β-lactamase-producing Enterobacteriaceae carriage at admission in an infant cohort at a tertiary teaching hospital in France

We describe risk factors associated with extended-spectrum β-lactamase-producing Enterobacteriaceae fecal carriage at admission in an infant population. 12.6% were carrying extended-spectrum β-lactamase-producing Enterobacteriaceae. Klebsiella pneumoniae, and Escherichia coli were the most frequently identified species. Prior antibiotic therapy (P = .016; odds ratio, 4.07; 95% confidence interval: 1.29-12.81) and the presence tracheostomy or gastrostomy (P = .018; odds ratio, 3.62; 95% confidence interval: 1.24-10.53) were independently associated with carriage at admission.

Klebsiella pneumoniae and type 3 fimbriae: nosocomial infection, regulation and biofilm formation

The Gram-negative opportunistic pathogen Klebsiella pneumoniae is responsible for causing a spectrum of nosocomial and community-acquired infections. Globally, K. pneumoniae is a frequently encountered hospital-acquired opportunistic pathogen that typically infects patients with indwelling medical devices. Biofilm formation on these devices is important in the pathogenesis of these bacteria, and in K. pneumoniae, type 3 fimbriae have been identified as appendages mediating the formation of biofilms on biotic and abiotic surfaces. The factors influencing the regulation of type 3 fimbrial gene expression are largely unknown but recent investigations have indicated that gene expression is regulated, at least in part, by the intracellular levels of cyclic di-GMP. In this review, we have highlighted the recent studies that have worked to elucidate the mechanism by which type 3 fimbrial expression is controlled and the studies that have established the importance of type 3 fimbriae for biofilm formation and nosocomial infection by K. pneumoniae.