Antimicrobial Resistance and Molecular Characterization of Staphylococcus aureus Causing Childhood Pneumonia in Shanghai.

Zhen Song,Xiao-Kui Guo,Ping He,Fei-Fei Gu,Li-Zhong Han,Yu-Xing Ni

doi:10.3389/fmicb.2017.00455

Zhen Song, Xiao-Kui Guo + Show 4 more

Open Access

https://doi.org/10.3389/fmicb.2017.00455

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Abstract

Staphylococcus aureus or methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen causing pneumonia among children. To estimate the prevalence and molecular properties of S. aureus in children pneumonia in Shanghai, China, 107 hospitalized children with S. aureus pneumonia from two children's hospitals from January 2014 through June 2015 were studied. S. aureus isolates from the respiratory specimens were characterized by antimicrobial susceptibility, agr typing, toxin genes, multilocus sequence typing (MLST), spa, and SCCmec typing. Fifty-eight (54.2%, 58/107) were MSSA (methicillin-susceptible Staphylococcus aureus) and 49 (45.8%, 49/107) were MRSA. No isolates were found resistant to teicoplanin, sulfamethoxazole/trimethoprim, rifampicin, quinupristin/dalfopristin, linezolid, or vancomycin. However, these isolates showed high resistant rates to erythromycin, fosfomycin-trometamol and clindamycin. The agrI (87/107, 81.3%) was the most common agr allele, followed by agrIII(10/107, 9.3%), agrII(9/107, 8.4%), and agrIV(1/107, 0.9%). Six pvl-positive isolates (3 MRSA and 3 MSSA) and 7 isolates of livestock associated clone ST398 (4 MRSA, 3 MSSA) were identified. CC59 was found in 35 isolates (33 MRSA and 2 MSSA), constituting majority of MRSA (33/49, 67.35%). The dominant CC were CC59 (32.7%), CC188 (13.1%), CC7 (12.1%) and CC398 (9.3%) while t172 (16.8%), t189 (12.1%), t437 (9.3%), and t091 (9.3%) were the most common spa types. In conclusion, more particular concern should appeal to ST59-SCCmecIV-t172/t437 as it is the most common epidemic clone causing pneumonia among children in Shanghai.

Highlights

Pneumonia causes high mortality among children under 5 years old
The morbidity of childhood pneumonia caused by S. aureus CA-methicillin-resistant Staphylococcus aureus (MRSA) has been increasing over the past two decades (Gonzalez et al, 2005; David and Daum, 2010)
Among the 107 pediatric S. aureus pneumonia patients enrolled in current study, 49 isolates were CA-MRSA according to the definition by J

Summary

Introduction

Pneumonia causes high mortality among children under 5 years old. According to data from the World Health Organization, there are more children died from pneumonia than AIDS, malaria and measles combined (Adegbola, 2012). 1–10% of communityacquired and 20–50% of nosocomial bacterial pneumonia in children were caused by S. aureus (Bradley, 2005; Chisti et al, 2009). S. aureus Causing Childhood Pneumonia in Shanghai of methicillin, MRSA (methicillin-resistant Staphylococcus aureus) has become major nosocomial pathogen worldwide, and was found in the community (community-associated MRSA, CA-MRSA) in the late 1980s. Four pediatric necrotizing pneumonia caused by CA-MRSA in 1999 raised a global public health concern (Centers for Disease Control and Prevention, 1999). It has been estimated that up to 40% of patients with CA-MRSA had severe or fatal pneumonia (Wallin et al, 2008; Carcillo et al, 2009)

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