Secular trends in pediatric bloodstream infections over a 20-year period at a tertiary care hospital in Germany

Epidemiology and Pathogenesis of Staphylococcus Bloodstream Infections in Humans: a Review

Staphylococci are among the most frequent human microbiota components associated with the high level of bloodstream infection (BSI) episodes. In predisposed patients, there is a high risk of transformation of BSI episodes to sepsis. Both bacterial and host factors are crucial for the outcomes of BSI and sepsis. The highest rates of BSI episodes were reported in Africa, where these infections were up to twice as high as the European rates. However, there remains a great need to analyze African data for comprehensive quantification of staphylococcal BSI prevalence. The lowest rates of BSI exist in Australia. Asian, European, and North American data showed similar frequency values. Worldwide analysis indicated that both Staphylococcus aureus and coagulase-negative staphylococci (CoNS) are the most frequent BSI agents. In the second group, the most prevalent species was Staphylococcus epidermidis, although CoNS were not identified at the species level in many studies. The lack of a significant worldwide decrease in BSI episodes indicates a great need to implement standardized diagnostic methods and research etiological factors using advanced genetic methods.

Risk Factors for Health Care-Associated Bloodstream Infections in a Neonatal Intensive Care Unit

Background

Healthcare-associated bloodstream infections (HCA-BSI) are a major cause of morbidity and mortality in neonatal intensive care units (NICUs).

Objectives

We aimed to determine the causative organisms and risk factors of HCA-BSIs in NICUs.

Methods

This study was performed between January 2011 and December 2014 in the neonatal intensive care unit of Dicle university, Turkey. The study consisted of 126 patients (infected group) with positive blood culture and 126 randomly selected patients (uninfected control group) with negative blood culture after four days of hospitalization.

Results

We found that the most common causative agents isolated from nosocomial infections (NIs) were 20.7% Staphylococcus epidermidis, 26.7% Klebsiella spp., and 13.3% Acinetobacter spp. Incidences of low gestational age, low birth weight, vaginal birth type, and long length of hospitalization were higher in the infected neonates than in the uninfected neonates. In the univariate analysis, surgical operation, ventriculoperitoneal shunt, use of umbilical catheter, nasogastric or orogastric tube, urinary catheter, mechanical ventilation, surfactant treatment, erythrocyte transfusion, plasma transfusion, thrombocyte transfusion, total parenteral nutrition infusion, intracranial hemorrhage, length of hospital stay, fifth-minute Apgar score, and total parenteral nutrition time were significantly associated with NIs. In the multiple logistic regression analysis, fifth-minute Apgar, use of erythrocyte transfusion and surgical operation were found as the independent risk factors for HCA-BSI.

Conclusions

This study determined the causative organisms and risk factors of HCA-BSIs in NICUs.

Mini-review: Epidemiology and zoonotic potential of multiresistant bacteria and Clostridium difficile in livestock and food

AIM

Information on the epidemiology of multiresistant bacteria (MRB) with zoonotic potential is growing but still remains quite incomplete. This narrative mini-review provides a general overview of the epidemiology of the most important zoonotic MRB in cattle, swine and poultry in Europe.

METHODS

A literature search was conducted mainly on the PubMed website including articles published until April 2012.

RESULTS

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) especially poses a zoonotic risk to people working in close contact with livestock. These people may become carriers themselves and the hazard of transmission into health-care facilities needs surveillance. Extended-spectrum beta-lactamases (ESBL) producing bacteria are widely spread in both humans and livestock, sharing similar genotypes, especially of the CTX-M-group, which makes a zoonotic transfer very likely. Identical strains of vancomycin-resistant enterococci (VRE) were found both in humans and animals, after ingestion of animal strains transient colonization of the human gut may be possible. Only a few data are available on the transmission of methicillin-resistant coagulase-negative staphylococci (MR-CoNS) between humans and animals. Direct contact to colonized animals may be a risk factor as well as the exchange of resistance genes between human and animal staphylococci. Clostridium difficile (C. difficile) ribotype 078 emerges in livestock and humans and a zoonotic transmission seems probable as genotypes and diseases resemble each other.

CONCLUSION

All discussed MRB and C. difficile are important nosocomial agents which also occur in livestock and were found in foods of animal origin. Further analysis is needed to reveal the exact transmission routes and to perform a reliable risk assessment.

A 4-year surveillance of device-associated nosocomial infections in a neonatal intensive care unit

BACKGROUND

The aim of this study was to determine the rate of health care-associated infection (HC-AI) and device-associated health care-associated infections (DA-HAIs), and distribution of causative microorganisms and etiologic factors responsible for these infections in a neonatal intensive care unit (NICU) of a state hospital in southeastern Turkey.

METHODS

A laboratory-based, active, prospective nosocomial infection surveillance study was performed in NICUs from January 2008 to December 2011. The rates of HC-AIs were determined on a daily basis. The findings were evaluated by applying the definitions of the Centers for Disease Control and Prevention National Healthcare Safety Network.

RESULTS

In a 4-year period, 580 HC-AIs, 81 of which were DA-HAIs, were detected among 6932 patients. The rate of hospital acquired infection was 8.3% and 7.69/1000 patient days. Ventilator-associated pneumonia (VAP) was the second most frequent (13.1%) HC-AI and the most frequent was DA-HAI. The VAP rate was 6.4 per 1000 ventilator days. Mechanical ventilation was the most frequently used invasive device. Median time to diagnosis of VAP was 32.11 ± 29.3 days from the time of admission. Acinetobacter baumannii (48%) and Pseudomonas aeruginosa (32%) were the most frequent microorganisms. Colistin was the most effective antibiotic by in vitro test. The antibiotic resistance ratios of A. baumannii were ≥54% for carbapenems, aminoglycosides, and cefoperazone-sulbactam; ≥88% for quinolones; and ≥92% for ceftazidime, ceftriaxone, and piperacillin-tazobactam.

CONCLUSIONS

Device-associated nosocomial infections was a particularly important problem in NICU. Close monitoring will decrease the rates of device-related nosocomial infections.

Pathogenesis of bloodstream infection in children with blood cancer

The aim of the present study was to characterize the distribution and antibiotic resistance of pathogens isolated from patients with bloodstream infections (BSIs) in the Hematology and Oncology department of the Affiliated Children’s Hospital of Zhejiang University Medical School (Hangzhou, China), between January and December 2010 and to provide early and appropriate support for the clinical administration of antibiotics. Out of 1,500 inpatients, 161 children who were diagnosed with BSI based on the national diagnostic criteria were retrospectively analyzed. Neutropenia was defined as an absolute neutrophil count (ANC) in the peripheral blood of less than 0.5×10⁹ cells/l. A microbiologically documented infection (MDI) was defined as when the causative pathogen was isolated from the blood. Drug susceptibility tests were performed using a VITEK-60 AutoMicrobic System and the Kirby-Bauer disk diffusion method. The data were analyzed using STATA software (version 9.0) and a two-sided P-value of ≤0.05 was considered to indicate a statistically significant difference. A total of 79 strains were isolated from the blood specimens. The incidence of BSI was 10.73% (161/1,500). Gram-positive cocci, Gram-negative bacilli and fungi accounted for 55.70, 43.04 and 1.27% of the BSIs, respectively. Staphylococcus epidermidis (20.25%), Escherichia coli (15.19%) and Klebsiella pneumoniae (15.19%) were frequently identified isolates. The staphylococci were susceptible to vancomycin and linezolid, while Escherichia coli and Klebsiella pneumoniae were sensitive to cefoperazone/sulbactam, imipenem and meropenem. In conclusion, Gram-positive bacteria are slightly more prevalent than Gram-negative bacteria in BSI and the selection of antibiotics according to the susceptibility test results is superior to empirical treatment. It is essential to administer antimicrobial agents early and appropriately to treat child blood cancer patients with BSI.