Efficacy of a once-a-week screening programme to control extended-spectrum beta-lactamase-producing bacteria in a neonatal intensive care unit

Multidrug-Resistant Gram-Negative Bacteria: Infection Prevention and Control Update

Multidrug-resistant gram-negative bacteria (MDR-GNB) pose one of the greatest challenges to health care today because of their propensity for human-to-human transmission and lack of therapeutic options. Containing the spread of MDR-GNB is challenging, and the application of multifaceted infection control bundles during an evolving outbreak makes it difficult to measure the relative impact of each measure. This article will review the utility of various infection control measures in containing the spread of various MDR-GNB and will provide the supporting evidence for these interventions.

Surveillance of multidrug-resistant bacteria in pediatric and neonatal intensive care units in Rio de Janeiro State, Brazil

INTRODUCTION

Multi-drug-resistant bacteria surveillance (MDR) systems are used to identify the epidemiology of MDR bacteria in neonates and children. This study aimed to describe the patterns by which MDR bacteria colonize and infect neonatal (NICU) and pediatric intensive care unit (PICU) patients in the state of Rio de Janeiro State, Brazil.

METHODS

A cross-sectional survey was performed using electronic data on NICU and PICU patients reported to the Rio de Janeiro State MDR bacteria surveillance system. All healthcare institutions that reported at least one case during the study period were included.

RESULTS

Between 2014 and 2017, 10,210 MDR bacteria cases, including 9261 colonizations and 949 infections, were reported. Among the colonizations, 5379 occurred in NICUs and 3882 in PICUs, while 405 infections occurred in NICUs and 544 in PICUs. ESBL producing Klebsiella sp and E. coli were the most reported colonization-causing agents in NICUs (1983/5379, 36.9%) and PICUs (1494/3882; 38.5%). The main causing bacteria reported in catheter-associated bloodstream infection (CLABSI), ventilator associated pneumonia, and catheter-associated urinary tract infection in NICUs were Klebsiella sp and E.coli (56/156, 35.9%), carbapenem-resistant Gram-negative bacteria (CRGNB) (22/65, 33.9%), and CRGNB (11/36, 30.6%) respectively, while in PICUs, they were MRSA (53/169, 31.4%), CRGNB (50/87, 57.4%), Klebsiella sp and E.coli (18/52, 34.6%), respectively.

CONCLUSIONS

MDR Gram-negative bacteria (ESBL producers and carbapenem-resistant bacteria) were the most reported agents among MDR bacteria reported to Rio de Janeiro surveillance system. Except for CLABSI in children, they caused all device-associated infections in NICUs and PICUs.

Outbreak of Yersiniabactin-producing Klebsiella pneumoniae in a Neonatal Intensive Care Unit

BACKGROUND

The Gram-negative bacterium Klebsiella pneumoniae is a frequent pathogen causing outbreaks in neonatal intensive care units. Some Enterobacteriaceae can acquire the ability to sequester iron from infected tissue by secretion of iron-chelating compounds such as yersiniabactin. Here we describe an outbreak and clinical management of infections because of a highly virulent yersiniabactin-producing, nonmultiresistant K. pneumoniae strain in a neonatal intensive care unit. Outbreak investigation and effectiveness assessment of multidisciplinary infection control measurements to prevent patient-to-patient transmission of highly pathogenic K. pneumoniae were undertaken.

METHODS

Outbreak cases were identified by isolation of K. pneumoniae from blood or stool of infants. Clinical data were abstracted from medical charts. K. pneumoniae isolates were genotyped using whole genome sequencing, and yersiniabactin production was evaluated by luciferase assay.

RESULTS

Fourteen cases were confirmed with 8 symptomatic and 6 colonized patients. Symptomatic patients were infants of extremely low gestational and chronologic age with fulminant clinical courses including necrotizing enterocolitis and sepsis. Whole genome sequencing for bacterial isolates confirmed the presence of an outbreak. All outbreak isolates produced yersiniabactin.

CONCLUSIONS

Yersiniabactin-producing K. pneumoniae can display a high pathogenicity in extremely premature infants with low chronologic age. This outbreak also underlines the considerable potential of today's infection control systems for recognizing and controlling nosocomial infections in highly vulnerable populations.

Reassessing the need for active surveillance of extended-spectrum beta-lactamase-producing Enterobacteriaceae in the neonatal intensive care population

OBJECTIVE

To determine the continued need for active surveillance to prevent extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) transmission in a neonatal intensive care unit (NICU).

DESIGN

This retrospective observational study included patients with ESBL-E colonization or infection identified during their NICU stay at our institution between 1999 and March 2018. Active surveillance was conducted between 1999 and March 2017 by testing rectal swab specimens collected upon admission and weekly thereafter. The overall incidence rates, of ESBL-E colonization or infection (including hospital acquired) before and after active surveillance were calculated. The cost associated with active surveillance was then estimated.

RESULTS

Overall, 171 NICU patients were found to have ESBL-E colonization or infection, and 150 of those patients (87.7%) were detected by active surveillance. The overall incidence rate was 1.4 per 100 patient admissions. The hospital-acquired incidence rate was 0.41 per 1,000 patient days, and this rate had decreased since 2002, with an average of 6 cases detected annually. A significant decrease was observed in 2009 when the unit moved to a new single-bed unit featuring private rooms. Active surveillance was discontinued with no increase in the number of infections. Of the 150 ESBL-E colonized patients, 14 (9.3%) subsequently developed an infection. Active surveillance resulted in a total of 50,950 specimen collections and a cost of $127,187 for processing, an average of $848 to detect 1 ESBL-E colonized patient.

CONCLUSION

ESBL-E transmission and infection in our NICU remains uncommon. Active surveillance may have contributed to the decline of ESBL-E transmission when used in conjunction with contact precautions and private rooms, but its relatively high cost could be prohibitive.

More Pathogenicity or Just More Pathogens?-On the Interpretation Problem of Multiple Pathogen Detections with Diagnostic Multiplex Assays

Modern molecular diagnostic approaches in the diagnostic microbiological laboratory like real-time quantitative polymerase chain reaction (qPCR) have led to a considerable increase of diagnostic sensitivity. They usually outperform the diagnostic sensitivity of culture-based approaches. Culture-based diagnostics were found to be insufficiently sensitive for the assessment of the composition of biofilms in chronic wounds and poorly standardized for screenings for enteric colonization with multi-drug resistant bacteria. However, the increased sensitivity of qPCR causes interpretative challenges regarding the attribution of etiological relevance to individual pathogen species in case of multiple detections of facultative pathogenic microorganisms in primarily non-sterile sample materials. This is particularly the case in high-endemicity settings, where continuous exposition to respective microorganisms leads to immunological adaptation and semi-resistance while considerable disease would result in case of exposition of a non-adapted population. While biofilms in chronic wounds show higher pathogenic potential in case of multi-species composition, detection of multiple pathogens in respiratory samples is much more difficult to interpret and asymptomatic enteric colonization with facultative pathogenic microorganisms is frequently observed in high endemicity settings. For respiratory samples and stool samples, cycle-threshold-value-based semi-quantitative interpretation of qPCR results has been suggested. Etiological relevance is assumed if cycle-threshold values are low, suggesting high pathogen loads. Although the procedure is challenged by lacking standardization and methodical issues, first evaluations have led to promising results. Future studies should aim at generally acceptable quantitative cut-off values to allow discrimination of asymptomatic colonization from clinically relevant infection.

The first occurrence of a CTX-M ESBL-producing Escherichia coli outbreak mediated by mother to neonate transmission in an Irish neonatal intensive care unit

BACKGROUND

Escherichia coli (E. coli) comprise part of the normal vaginal microflora. Transfer from mother to neonate can occur during delivery resulting, sometimes, in neonatal bacterial disease. Here, we aim to report the first outbreak of CTX-M ESBL-producing E. coli with evidence of mother-to-neonate transmission in an Irish neonatal intensive care unit (NICU) followed by patient-to-patient transmission.

METHODS

Investigation including molecular typing was conducted. Infection was defined by clinical and laboratory criteria and requirement for antimicrobial therapy with or without positive blood cultures. Colonisation was determined by isolation without relevant symptoms or indicators of infection.

RESULTS

Index case was an 8-day-old baby born at 34 weeks gestation who developed ESBL-producing E. coli infections at multiple body sites. Screening confirmed their mother as colonised with ESBL-producing E. coli. Five other neonates, in the NICU simultaneously with the index case, also tested positive. Of these, four were colonised while one neonate developed sepsis, requiring antimicrobial therapy. The second infected neonate's mother was also colonised by ESBL-producing E. coli. Isolates from all eight positive patients (6 neonates, 2 mothers) were compared using pulsed-field gel electrophoresis (PFGE). Two distinct ESBL-producing strains were implicated, with evidence of transmission between mothers and neonates for both strains. All isolates were confirmed as CTX-M ESBL-producers. There were no deaths associated with the outbreak.

CONCLUSIONS

Resources were directed towards control interventions focused on hand hygiene and antimicrobial stewardship, which ultimately proved successful. Since this incident, all neonates admitted to the NICU have been screened for ESBL-producers and expectant mothers are screened at their first antenatal appointment. To date, there have been no further outbreaks.

Multidrug-Resistant Gram-Negative Bacilli: Infection Control Implications

Antimicrobial resistance is a common iatrogenic complication of both modern life and medical care. Certain multidrug resistant and extensively drug resistant Gram-negative organisms pose the biggest challenges to health care today, predominantly owing to a lack of therapeutic options. Containing the spread of these organisms is challenging, and in reality, the application of multiple control measures during an evolving outbreak makes it difficult to measure the relative impact of each measure. This article reviews the usefulness of various infection control measures in containing the spread of multidrug-resistant Gram-negative bacilli.

Optimizing the Use of Antibacterial Agents in the Neonatal Period

Antibiotics are invaluable in the management of neonatal infections. However, overuse or misuse of antibiotics in neonates has been associated with adverse outcomes, including increased risk for future infection, necrotizing enterocolitis, and mortality. Strategies to optimize the use of antibiotics in the neonatal intensive care unit include practicing effective infection prevention, improving the diagnostic evaluation and empiric therapy for suspected infections, timely adjustment of therapy as additional information becomes available, and treating proven infections with an effective, narrow-spectrum agent for the minimum effective duration. Antibiotic stewardship programs provide support for these strategies but require the participation and input of neonatologists as stakeholders to be most effective.

Extended-spectrum β-lactamase-producing Enterobacteriaceae among pregnant women in Norway: prevalence and maternal-neonatal transmission

OBJECTIVE

To study (i) the prevalence and risk factors for carriage of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) in pregnant women, (ii) the maternal-neonatal transmission rate of ESBL-E at birth and (iii) the prevalence of ESBL-E in expressed breast milk of colonized mothers.

STUDY DESIGN

In this cross-sectional, population-based study with case follow-up on maternal-neonatal transmission of ESBL-E, women were screened for rectal ESBL-E colonization at 36 weeks of pregnancy and delivery. Possible risk factors for colonization were studied by logistic regression. Infants of ESBL-E-positive mothers were screened for ESBL-E during their first weeks of life. ESBL-encoding genes were detected by PCR and clonal relatedness was investigated by pulsed-field gel electrophoreses.

RESULTS

In total, 26 out of 901 (2.9%) women were colonized by ESBL-producing Escherichia coli at 36 weeks of pregnancy. One of the women carried an additional ESBL Klebsiella pneumoniae strain. Adjusted for traveling, African or Asian nationality was a risk factor for colonization; OR=5.62 (2.21, 14.27) (LR-p=0.003). Fourteen women remained ESBL-E carriers at delivery. ESBL-E strains indistinguishable from the strains isolated from their respective mothers were detected in 5 (35.7%) infants during their first days of life (median day 3; range=2 to 8). A total of 146 expressed milk samples were cultured from 25 out of 26 colonized mothers, all were ESBL-E negative.

CONCLUSIONS

The prevalence of ESBL-E carriage among pregnant women was low in our region, but the high maternal-neonatal transmission rate suggests that colonized mothers represent a substantial risk for infant colonization.