Objective To survey and analyze the drug resistance of clinical isolated strains of bloodborne infectious staphylococci, in order to provide references for clinical diagnosis of aureus septicemia and rational use of antimicrobial agents. Methods We retrospectively studied the clinical data of 496 patients with staphylococcal septicemia confirmed by blood culture between June 2008 and May 2015 in West China Hospital of Sichuan University. The microbiological characteristics of the disease were analyzed. Results In the included 496 cases, there were 216 (43.55%) cases of coagulase-positive Staphylococcus (CPS) septicemia and 280 (56.45%) of coagulase-negative Staphylococcus (CNS) septicemia; 85 (17.14%) cases were caused by community infection, while the other 411 (82.86%) resulted from hospital infection. The drug resistance rate of CPS and CNS toward oxacillin was respectively 27.78% (60/216) and 87.50% (245/280), with a significant difference (P < 0.05). In al l the clinical isolated strains of CPS, the drug resistance rate of community infected strains and hospital infected strains toward oxacillin was respectively 9.67% (6/62) and 35.06% (54/154), with a significant difference (P < 0.05). For the clinical isolated strains of CNS, the drug resistance rate of community infected strains and hospital infected strains toward oxacillin was respectively 69.57% (16/23) and 89.11% (229/257), also with a significant difference (P < 0.05). Conclusions The drug resistance of hospital infected staphylococcal strains is stronger than community infected strains. The CNS strains are more drug-resistant than CPS strains.
ObjectiveTo investigate the positive rates of virulence genes ply, lytA and nanA in Streptococcus pneumoniae (SP) strains isolated from different sources and the pathogenesis.MethodsA total of 147 and 24 strains of SP were isolated from sputum and blood samples of hospitalized children in Tongji Hospital of Wuhan from 2015 to 2016, respectively. Such strains of SP were analyzed by automated microbial analyzer VITEK Compact-2 and confirmed by its specific gene pbp2B using regular polymerase chain reaction (PCR) method. Then PCR method was used to detect the carriers of the virulence genes ply, lytA and nanA, and calculated the fatality and hospitalization days of patients.ResultsPositive rates of virulence genes ply, lytA and nanA were 95.9%, 96.6% and 88.4% respectively for 147 strains isolated from sputum, and were 100.0%, 100.0% and 79.2% respectively for those from blood. Between the 147 children with pneumonia and 24 children with septicemia, there was no statistically significant difference in fatality [ 8.3% (2/24) vs. 0.7% (1/147), P=0.052], but there was a significant difference in length of hospital stay [(14.2±2.4) vs. (6.4±1.5) d; t=21.303, P<0.001].ConclusionsThe positive rate of SP virulence gene nanA is lower than those of ply and lytA. The positive rates of SP virulence genes ply, lytA and nanA are similar from different sources. Significant difference may be found for hospitalization days among different types of SP infections.