[Gene typing and antibiotic resistance of methicillin-resistant Staphylococcus aureus isolated from lower respiratory tract at two hospitals in Shanghai].
OBJECTIVE
To study the genotyping characteristics and antibiotic resistance of methicillin-resistant Staphylococcus aureus(MRSA) isolated from lower respiratory tract at 2 different level hospitals in Shanghai.


METHODS
The subjects included 155 patients at Ruijin Hospital and Tongren Hospital between January 2013 and June 2014, including 108 males and 47 females, with a mean age of 67.8±16.5. The 155 MRSA strains were isolated from lower respiratory tract specimens and multilocus sequence typing (MLST) and spa typing were analyzed by the PCR method. The antimicrobial resistance of MRSA was tested by VITEK-32. Fisher's exact test was used for statistical analysis.


RESULTS
Among the 155 strains, 28 MLST-spa molecular types were identified, of which ST764-t002(41.29%), ST239-t037(17.42%) and ST239-t030(10.32%) were the most predominant types. The MRSA strains were susceptible to linezolid, vancomycin and teicoplanin, and also had a lower resistance to trimethoprim-sulfamethoxazole and rifampin, with a susceptible rate of 83.9% and 83.2% respectively, but were highly resistant to other antibiotics. The resistance rate of ST239-t037 to trimethoprim-sulfamethoxazole was higher than that of other types, and the resistance rate of ST239-t030 to rifampin was higher than that of other types, the differences being significant(P<0.001). The mean length of hospital stay of the 155 patients was (97±84) days, and mechanical ventilation were used in 78(50.3%) patients, while 108(69.7%))patients received invasive procedures. Broad-spectrum antibiotics were used in 136 (87.1%) patients. There were differences in age, hospitalization days, smoking history, history of COPD, mechanical ventilation, and operation between the 2 hospitals(P<0.05).


CONCLUSIONS
Most of the MRSA strains at Ruijin Hospital and Tongren Hospital between January 2013 and June 2014 were multi-drug resistant, and the susceptibility spectrum of different genotypes was different.
Department of Pulmonary Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China.
R
R
Wang
H Y
HY
Wan
G C
GC
Shi
M
M
Li
L Z
LZ
Han
X Y
XY
Jin
Q
Q
Sun
P
P
He
M
M
Zhou
D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D002681:China; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification* / Q000187:drug effects* / Q000302:isolation & purification; D008875:Middle Aged; D058885:Multilocus Sequence Typing; D012137:Respiratory System / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000382:microbiology*
D000900:Anti-Bacterial Agents