Bacteriologic profile and drug resistance in children with respiratory infection from 2016 to 2018 / 中国当代儿科杂志

OBJECTIVE@#To study the bacteriologic profile and drug resistance of respiratory infection in children, and to provide a basis for etiological diagnosis and rational use of antimicrobial agents.@*METHODS@#A retrospective analysis was performed for 15 047 children who attended the hospital due to respiratory infection from January 2016 to December 2018. Their sputum samples were collected, and the Phoenix-100 automatic microbial identification system was used for the identification and drug sensitivity analysis of the isolated pathogenic bacteria.@*RESULTS@#Of all 17 174 sputum samples detected, there were 2 395 positive samples, with a positive rate of 13.95%; a total of 2 584 strains of pathogenic bacteria were isolated, among which there were 1 577 (61.03%) Gram-negative strains, 967 (37.42%) Gram-positive strains, and 40 (1.55%) fungal strains. The most common pathogen was Haemophilus influenzae (33.90%), followed by Streptococcus pneumoniae (33.55%), Moraxella catarrhalis (19.20%), and Staphylococcus aureus (3.64%). Among the 2 331 children with positive infection, 251 had mixed infection, most commonly with Haemophilus influenzae and Streptococcus pneumoniae. The detection rate of pathogenic bacteria was higher in winter and spring and lower in summer and autumn. There was a significant difference in the detection rate of pathogenic bacteria between different age groups (P<0.05), with the highest detection rate in infants aged 1 month to <1 year. Streptococcus pneumoniae and Staphylococcus aureus had a sensitivity rate of 100% to vancomycin, linezolid, and teicoplanin, and Haemophilus influenzae had a lower sensitivity rate to ampicillin, compound sulfamethoxazole and cefuroxime and a higher sensitivity rate to other drugs.@*CONCLUSIONS@#Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis are the main pathogenic bacteria of respiratory infection in children, and mixed infection is the most common type of infection. The detection rate of pathogenic bacteria varies across seasons and ages. Different pathogenic bacteria have different features of drug resistance, and antibiotics should be selected based on drug sensitivity results.

Characterization of qnr gene for plasmid-mediated quionlone resistance / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore the distribution of qnr gene and broad spectrum p-lactamase (ESBLs) gene in gram-negative bacteria which were isolated from our hospital patients.</p><p><b>METHODS</b>qnr gene in nonrepetitive 129 isolates of Escherichia coli, 10 isolates of Enterobacter cloacac and 29 isolates of K. pneunoniae were detected by polymerase chain reaction (PCR). For qnr gene positive strains, int I, SHV-1, TEM-1, CTX-M, OXA-I , OXA-II , OXA-III, DHA and EBC genes were examined. Plasmid conjugatable test was applied to examine whether qnr gene was located in conjugate plasmid and ERIC-PCR was carried out for DNA homologous analysis. ESBLs detection (according to phenotypic confirmatory test based on National Committee for Clinical Laboratory Standards criteria) and susceptibility test to 16 antibiotics were also performed.</p><p><b>RESULTS</b>qnr gene was found in 6 clinical isolates including 5 strain of E. coli and one strain of E. cloacac, but qnr gene was undetectable in K. pneunoniae isolates. The 6 clinical isolates were suspectible to imipenem but resistance to some other drugs while only 2 isolates of E. coli were susceptible to quinolone. Among the 6 qnr gene-positive strains, all of them belonged to I type integron-positive isolates, 4 isolates of them were TEM-1 producing strains,with only one isolate was OXA-III gene producing strain, and 2 isolates of them were EBC producing strains. Most of them were with 2 ESBLs gene if not more. qnr gene was on transferable plasmids which could be disseminated by clone.</p><p><b>CONCLUSION</b>In Wuhan city, the prevalence of qnr was confirmed. qnr gene were found with some ESBLs gene in the same strains, and qnr gene in suspect strains. The transmission of qnr gene producing strains could be mediated by transferable plasmids or clone, forcing us to make intensive investigation and take effective control measures.</p>

Detection of the qnr gene responsible for plasmid-mediated quinolone resistance / 中国感染与化疗杂志

Objective To explore the prevalence of qnr gene in gram-negative bacteria isolated from Renmin Hospital of Wuhan University. Methods qnr gene was detected by PCR in non-duplicate E.coli (n=129), E.cloacae (n=10) and K.pneumoniae (n=29) isolates.PCR technique was used to amplify the gene encoding type I integrons.Kirby-Bauer disk diffusion method was used to test the in vitro suscepti- bility of the isolates to 16 antimicrobial agents.ESBLs were investigated according to phenotypie screening and confirmatory test recom- mended by NCCLS.MIC values of ciprofloxacin were determined for qnr gene positive strains.Results qnr gene were identified in 6 clinical isolates including 5 strains of E.coli and I E.cloacae, qnr gene was not found in K.pneumoniae isolates.The 6 qnr-positive clinical iso- lates were positive for type I integrons.All the 6 strains were susceptible to imipenem but resistant to many other drugs tested.Only 2 of the E.coli isolates were susceptible to ciprofloxacin.Conclusions In Hubei Province, the prevalence of qnr is confirmed.The serious situa- tion of multidrug-resistance in clinical isolates with qnr gene requires careful monitoring of qnr-carrying isolates.

A case-control study on the risk factors of nosocomial infection caused by imipenem-resistant Pseudomonas aeruginosa / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore the risk factors for nosocomial infection caused by imipenem-resistant Pseudomonas aeruginosa (IRPA).</p><p><b>METHODS</b>A case-control study was carried out for the comparison of 2 groups of 'case' patients with 'controlled' patients. The first group of 'case' patients had nosocomial isolation of IRPA, and the second group had imipenem-susceptible Pseudomonas aeruginosa (ISPA). 'Control' patients were selected from the same medical or surgical services from which 'case' patients were receiving care when isolation of IRPA or ISPA occurred. Risk factors analyzed included the use of antimicrobials, comorbid conditions, and demographic variables. IRPA was recovered from 67 patients, and ISPA from 150 patients while the control case were 200 and 159 respectively. All patients were from Renmin Hospital of Wuhan University during Jan 2002 to Dec 2003. Data were analyzed with unconditional logistic regression and principal component analysis.</p><p><b>RESULTS</b>Data from multivariate unconditional logistic regression analysis showed that the independent risk factors for IRPA nosocomial infection were: time at risk (OR = 1.03, 95% CI: 1.01-1.04), imipenem (OR = 4.65, 95% CI: 1.35-11.52), PIP/TAZ (OR = 3.37, 95% CI 1.85-9.43) and quinolones (OR = 1.85, 95% CI: 1.25-5.34) while the third cephalosporins (OR = 2.54, 95% CI: 1.26-5.23) and aminoglycoside antibiotics (OR = 1.86, 95% CI 1.42-3.26) time at risk (OR = 1.05, 95% CI: 1.03-1.05) were associated with isolated ISPA.</p><p><b>CONCLUSION</b>Nosocomial infection of IRPA could be caused by the use of imipenem and other antibiotics, suggesting that to limit the use of imipenem was not sufficient to contain the increasing incidence of IRPA.</p>