title: [Pathologic bacterial distribution and antibiotic resistance in induced sputum of infants aged from 1 to 3 months with lower respiratory tract infection].
abstract: OBJECTIVE
  To investigate the pathologic bacterial distribution and their antibiotic resistance in infants aged from 1 to 3 months with lower respiratory tract infection, so as to provide instructions for clinical application of antibiotics.
  
  
  METHODS
  Induced sputum was extracted from 622 cases of hospitalized infants aged from 1 to 3 months with lower respiratory tract infection between January 2013 and December 2013, and microbial sensitivity test was performed with agar diffusion sensitivity test.
  
  
  RESULTS
  A total of 379 (60.9%) strains of bacteria were isolated from induced sputum in the 622 infants. The Gram-negative strains were detected in 325 strains (85.8%), and the Gram-positive strains were found in 50 strains (13.2%) in the 379 strains. The others were Fungal strains (4 strains, 1.1%). The Gram-negative bacteria included Escherichia coli (31.1%) and Klebsiella pneumoniae (18.2%), with extended-spectrum β-lactamases (ESBLs) production of 48.3% and 52.2% respectively. The average rate of antibiotic resistance for ESBLs-producing bacteria was 53%. ESBLs-producing bacteria were highly resistant (100%) to ampicillin and cefotaxime, but sensitive to carbapenems. Staphylococcus aureus (10.0%) was the dominant bacteria in Gram-positive bacteria. A lower proportion of methicillin-resistant Staphylococcus aureus (1.8%) was observed, however the resistance rate of methicillin-resistant Staphylococcus aureus to β-lactam antibiotics were 100%.
  
  
  CONCLUSIONS
  Escherichia coli and Klebsiella pneumoniae are the main pathogenic bacteria causing lower respiratory tract infection in infants aged from 1 to 3 months. ESBLs-producing bacteria accounted for over 48%, and the antibiotic resistance rate were more than 53% in these infants. These results provide a basis for the first empirical clinical use of antimicrobial in infants with lower respiratory tract infection.
authors.affiliation: Department of Pediatrics, Xiaogan Central Hospital Affitiated to Tongji Medical College of Huazhong University of Science and Technology, Xiaogan, Hubei 432100, China. LHLLL3@sina.com.
authors.forename: Man-Feng
authors.initials: MF
authors.lastname: Zuo
authors.forename: He-Lin
authors.initials: HL
authors.lastname: Liu
authors.forename: Mu-Liang
authors.initials: ML
authors.lastname: Zhu
authors.forename: Qiong-Zhang
authors.initials: QZ
authors.lastname: Shu
authors.forename: Ling
authors.initials: L
authors.lastname: Jiang
mesh_terms: D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000302:isolation & purification; D005260:Female; D006801:Humans; D007223:Infant; D007711:Klebsiella pneumoniae / Q000302:isolation & purification; D008297:Male; D012141:Respiratory Tract Infections / Q000188:drug therapy / Q000382:microbiology*; D013183:Sputum / Q000382:microbiology*