The intestinal carrier status of Enterococcus spp. in children: clonal diversity and alterations in resistance phenotypes before and after admission to a pediatric intensive care unit.

BACKGROUND: This study aimed to investigate the intestinal carrier status of Enterococcus spp. among children in a pediatric intensive care unit (PICU) and reveal the role of hospitalization in the alteration of resistance phenotypes and clonal diversity of the isolates during admission and discharge periods. METHODS: Two separate stool samples were collected from hospitalized patients in the pediatric intensive care unit at admission and discharge times. The culture was done, and Enterococcus species were tested for antimicrobial susceptibility and carriage of vanA-D gene subtypes. Random Amplified Polymorphic DNA (RAPD)-PCR was used for a phylogenetic study to check the homology of pairs of isolates. RESULTS: The results showed carriage of Enterococci at admission, discharge, and at both time points in 31%, 28.7%, and 40.1% of the cases, respectively. High frequencies of the fecal Enterococcus isolates with vancomycin-resistance (VR, 32.6% and 41.9%), high-level of gentamicin-resistance (HLGR, 25.6% and 27.9%), and multi-drug resistance phenotypes (MDR, 48.8% and 65.1%) were detected at admission and discharge times, respectively. Resistance to vancomycin, ampicillin, and rifampicin was higher among E. faecium, but resistance to ciprofloxacin was higher in E. faecalis isolates. The increased length of hospital stay was correlated with the carriage of resistant strains to vancomycin, ampicillin, and ciprofloxacin. While the homology of the isolates was low among different patients during hospitalization, identical (9%) and similar (21%) RAPD-PCR patterns were detected between pairs of isolates from each patient. CONCLUSIONS: The high rate of intestinal carriage of VR, HLGR-, and MDR-Enterococci at admission and during hospitalization in the PICU, and the impact of increased length of hospital stay on the fecal carriage of the resistant strains show the importance of antibiotic stewardship programs to control their transmission and spread in children.

Intestinal colonization of vancomycin-resistant Enterococcus in children admitted to Mofid children's hospital intensive care unit at admission and at discharge.

BACKGROUND: This study aimed to investigate the frequency of intestinal colonization by vancomycin-resistant Enterococcus (VRE) carrying vanA and vanB genes in patients at ICU admission and at discharge from ICU in Mofid children's Hospital, Tehran, Iran. METHOD: Sampling was performed using rectal swabs and vancomycin susceptibility testing for Enterococcus spp. was carried out using a minimum inhibitory concentration (MIC) assay on Muller Hinton Agar (MHA) medium using an E-test kit. The molecular detection of VRE isolates was performed by the PCR method using the vanA and vanB resistance genes. RESULTS: A total of 234 and 186 non-duplicate rectal swab samples were collected from patients at ICU admission and at discharge from ICU, respectively. Enterococcus spp. was detected in 34.6% (n = 81/234) of rectal swab samples collected from patients at ICU admission, of which 44.4% (n = 36/81) were VRE isolates. In contrast, the prevalence of Enterococcus spp. and VRE isolates among patients at discharge from ICU was 17.7% (n = 33/186) and 57.6% (n = 19/33), respectively. Out of 19 VRE isolated from patients at ICU admission, 4 (21%) and 1 (5.3%) contained vanA and vanB genes, respectively. In contrast, out of 36 VRE isolated from patients at discharge from ICU, 11 (30.5%) were positive for the vanA gene. CONCLUSION: Results revealed that the prevalence of Enterococcus spp. among patients at ICU admission was high. However, VRE was frequently isolated from patients who were hospitalized for several days in ICUs. The implementation of proper infection control strategies and the use of suitable protocols to guide the appropriate prescribing of antibiotics are necessary.

Evaluating the antimicrobial resistance patterns among major bacterial pathogens isolated from clinical specimens taken from patients in Mofid Children's Hospital, Tehran, Iran: 2013-2018.

BACKGROUND: This study evaluates the epidemiology and antimicrobial resistance profile of Gram-negative bacteria (GNB) and Gram-positive bacteria (GPB) isolated from clinical specimens in children admitted to Mofid Children's Hospital. METHODS: This was a retrospective study of the patients' clinical specimens collected from January 2013 until the end of December 2018. All specimens were evaluated to determine the presence of infection-causing agents using a BACTEC 9120 blood culture. Isolation and identification of bacterial strains were performed using conventional biochemical tests. Antibiotic resistance was determined using Kirby-Bauer disk diffusion and broth microdilution methods. Results were interpreted according to CLSI and EUCAST. RESULTS: A total of 1130 different pathogenic bacteria were detected from 14,690 different clinical specimens and the overall detection rate was 7.7% (1130/14,690). Among bacterial pathogen isolated from clinical specimens, 55% (n=622) were GNB and 45% (n=508) were GPB. The predominant GNB isolates were Pseudomonas aeruginosa, Klebsiella spp., Acinetobacter baumannii, Escherichia coli, Enterobacter spp., Citrobacter spp., respectively. Among GPB, CoNS was the most frequent and Enterococcus spp. was found to have low levels of resistance to linezolid. In GNB, most A. baumannii and P. aeruginosa were ceftriaxone resistant. P. aeruginosa was found to have low levels of resistance to levofloxacin and ciprofloxacin. CONCLUSIONS: Our findings revealed that the resistance rate among GNB and GPB associated with different infections in children is very high. These results suggest a constant screening and follow-up programs for the detection of antibiotic resistance, and it also suggests to develop antimicrobial stewardship programs in Tehran, Iran.

Study Prevalence of Verotoxigenic E.coli Isolated from Urinary Tract Infections (UTIs) in an Iranian Children Hospital.

BACKGROUND AND OBJECTIVES: Urinary tract infections (UTI) caused by enterohemorrhagic Escherichia coli (EHEC) is one of the most important diseases in infants and children. If there would not be any useful diagnosis and treatment it may be resulted in diseases such as acute renal failure, thrombocytopenia and hemolytic anemia. The aim of this study was to determine frequency of verotoxigenic E.coli isolates in urine of children with (UTIs) in Mofid children Hospital. METHODS: During one year from September 2008 to august 2009, urine specimens were taken from children who suspected to UTI admitted to Mofid Children Hospital. E.coli strains that indicated beta hemolytic on sheep blood agar, negative sorbitol fermentation on SMAC (sorbitol macconky agar) and negative motility on SIM were tested by PCR and serologic (VITEC-RPLA kit) methods for detecting toxin genes and production of toxin, respectively. RESULTS: Among 12572 urine specimens were taken from children admitted to Mofid hospital, we isolated 378 E.coli from urine samples which only 9 isolates were EHEC. Only five EHEC strains (55%) which produced vtx genes, were detected by serologic and PCR methods. CONCLUSION: The prevalence of urinary infections caused by EHEC strains is very significant because it causes aggravating pathologic effects. Thus we suggest rapid method for identification of this bacteria and proper treatment to Inhibition of unwanted complications.

Serologic evidence of pertussis infection in vaccinated Iranian children.

BACKGROUND: It seems that the incidence of pertussis-like illnesses is considerably increasing despite the wide coverage of immunization with the whole cell pertussis vaccine. We aimed to investigate the occurrence of pertussis in vaccinated children by measuring anti-pertussis antibodies. METHODS: In this cross-sectional study, blood samples were taken from vaccinated children aged 2, 4, 6, 12, 18, and 72 months. Anti-pertussis IgG and IgA were measured by ELISA. P<0.05 was considered significant. RESULTS: 725 children were enrolled in the study. Geometric mean titers for IgG that showed a slight decease after 2 months of age and increased distinctly in children aged 72 months. The frequency of the individuals whose IgG was above the determined cut-off (derived from mean+2SD) was observed in 1% of the 2, 4, and 6-month-old infants, 6% of the 12 and 18-month-olds and 12% of the 6-year -old children. Positive IgA titers were detected in 5, 9, 6, 23, 11, and 8% of children aged 2, 4, 6, 12, 18, and 72 months, respectively. CONCLUSION: Since a considerable percentage of children had high levels of anti-pertussis IgG antibodies (≥2 SD), positive anti-pertussis IgA, and most importantly an increased level of anti-pertussis IgG geometric mean titer at 6 years of age, further investigations regarding the protection provided by the presently used pertussis vaccine seems necessary.