Objective To investigate the distribution and antibiotic resistance of bacterial isolates from blood samples in pediatric patients in tertiary hospitals in Hubei area from 2006 to 2007.Methods Pathogenic bacteria isolated from blood samples of pediatric patients were collected from 17 tertiary hospitals in Hubei area from 2006 to 2007. All strains were isolated and identified by routine Methods . Antimicrobial susceptibility testing was conducted on all isolates using Kirby-Bauer Methods . Results A total of 941 strains were collected from January to December of 2006. The most common microorganism was coagulase-negative Staphylococcus (573, 60.9%), followed by Staphylococcus aureus (127, 13.5%), Enterococcus faecalis (33, 3.5%), Escherichia coli (16, 1.7%). A total of 969 strains were collected from January to December of 2007. The most common species was coagulase negative Staphylococcus (583, 60.2%), followed by S. aureus (162, 16.7%), E. faecalis (28, 2.9%), E. coli (21, 2.2%), E. faecium (11, 1.1%), Salmonella choleraesuis (11, 1.1%). Of the isolates collected during 2006, the prevalence of methicillin-resistant S. aureus (MRSA) was 71.7%. The prevalence of ESBLs was 56.2% in E. coli. Of the isolates collected during 2007, the prevalence of MRSA was 79.6%. The prevalence of ESBLs was 47.6% in E. coli. MRSA strains were more resistant to antibiotics than methicillin-susceptible S. aureus (MSSA). No glycopeptide-resistant strain was identified in Staphylococcus. Conclusions Staphylococcus is the most frequently isolated pathogen from blood samples of pediatric patients in tertiary hospitals in Hubei area.

Objective To investigate the genotypes of aminoglycoside-modifying enzymes (AMEs) produced by Pseudomonas aeruginosa isolated from Huaibei Miner's General Hospital.Methods Minimum inhibitory concentration of 36 strains of P. aeruginosa to 3 aminoglycoside antibiotics was determined. AME genes were amplified by polymerase chain reaction (PCR). Results The P. aeruginosa isolates were resistant to multiple antibiotics. Most (62.2% to 81.1%) were resistant to aminoglycosides. And 27 strain (75.0%) carried one or more types of AME genes, including ant(3″)-Ⅰ (63.9%), aac(6')-Ⅱ (58.3%), aac(6')-Ⅰ (50.0%), aac(3)-Ⅱ (38.9%) and ant(2″)-Ⅰ (36.1%). The aac(3)-Ⅰ, aac(3)-Ⅲ, aac(3)-Ⅳ, aph(3')-Ⅳ genes were not identified.Conclusions The study indicates that the P. aeruginosa isolates in Huaibei are multi-resistant to aminoglycoside antibiotics. The prevalence of AMEs-positive strains is high.

Objective To investigate the prevalence of 16S rRNA methylase genes, armA and rmtB, which mediate high level aminoglycoside resistance, in gram-negative bacteria isolated from 2 hospitals in Dalian and study the mechanism of aminoglycoside resistance.Methods A total of 134 amikacin-resistant clinical isolates of gram-negative bacteria were collected. Two 16S rRNA methylase genes, armA and rmtB, were identified by PCR-based assays. PCR products were extracted for DNA sequencing analysis. armA and rmtB gene mapping were conducted by plasmid extraction, conjugation and transformation. The MICs of amikacin, gentamicin and tobramycin were determined for the positive isolates, transconjugants and the resultant strain of transformation using agar dilution technique. Results Overall armA was identified in 21 strains of Acinetobacter baumannii, rmtB in 5 strains of Escherichia coli and 5 strains of Klebsiella pneumoniae. Plasmid extraction and conjugation experiments were only successful for rmtB-positive isolates. Transconjugant and DH5a (pMDarmA) exhibited high-level resistance to aminoglycosides.Conclusions The 16S rRNA methylase genes, armA and rmtB are identified in Dalian. armA gene is identified in A. baumannii. rmtB gene is located on the plasmid of E. coli and K. pneumoniae. armA and rmtB can induce high-level resistance to aminoglycosides.

Objective To analyze the clinical, radiological, pathological and microbiological features of invasive pulmonary aspergillosis (IPA) to improve clinical management.Methods Retrospective analysis of 20 pathologically and/or microbiologically confirmed IPA cases in our hospital from January 2005 to August 2008. Results Group A (with underlying diseases) included 13 patients (underlying malignancy in 9 patients, including 5 cases of hematological malignancy, COPD in 2 patients, pulmonary tuberculosis and bronchiectasis in 1 each). Group B (without underlying disease) included 7 patients (2 patients with a long time of fluffy toy contact, another 1 had exposure to moldy rice, and 3 had exposure to polluted water). All these 20 patients had pulmonary invasion revealed by CT imaging. Multiple changes were identified in 16 patients. Bilateral pulmonary infiltrates and/or consolidation were revealed in 7 patients. Multiple nodules were seen in 9 patients. Four patients had solitary lesions, including isolated nodules in 2 patients and segment consolidation in the other 2 patients. Pulmonary cavity without fluid level was found in 8 patients (40.0%). Eighteen cases received antifungal therapy. The overall efficacy rate was 55.6%. The efficacy rate in group A and B was 45.5% and 5/7 respectively. The average time to symptomatic relief was (12.0±2.8) days. The time to lung lesion improvement on CT was (17.4±2.9) days. The time to significant CT improvement was (34.3±9.9) days. The time to the resolution of active lesion was (56.4±6.2) days.Conclusions IPA may occur in immunocompetent patients without underlying disease. Most IPA patients have bilateral multiple pulmonary nodules and cavities on CT. The time to the resolution of active pulmonary lesions is about 6 weeks.

Objective To investigate the clinical manifestations, imaging features, diagnosis and management of pulmonary mycosis.Methods Fifty-four patients were identified with pulmonary mycosis by pathological examination in our hospital from January 2002 to June 2008. Data of clinical manifestations, imaging features, diagnosis and management were retrospectively reviewed.Results Of the 54 cases, 30 (55.6%) were pulmonary aspergillosis, 15 (27.8%) were pulmonary cryptococcosis. Underlying disease was reported in 42 of 54 (77.8%) cases. The diagnosis of all the patients was confirmed by pathological exami-nation. Lung or bronchi tissue was obtained by operation in 30 (55.6%) cases, by bronchofibroscope in 12 (22.2%) cases, by CT-guided percutaneous needle biopsy in 9 (16.7%) cases, and by lymphoid node biopsy in 4 cases. Main symptoms included cough (41, 75.9%), expectoration (30, 55.6%), hemoptysis (20, 37.0%), fever (16, 29.6%), and asymptomatic (6, 11.1%). The X-ray and chest CT showed masses or nodule lesions (41, 75.9%), patchy lesions (8, 14.8%), cavity (12, 22.2%), diffuse milliary nodules (1 case). Bilateral lungs were involved in 7 cases (13.0%);right lung alone in 26 cases (48.1%);left lung alone in 21 cases (38.9%). Among the 54 cases, 41 (75.9%) were misdiagnosed before pathological examination. Thirty (55.6%) cases underwent surgical resection of pulmonary lesions. One patient suffered from cryptococcal meningitis after operation. Twenty (37.0%) patients received systemic anti-fugal therapy. Cure or significant improvement was found in 16 cases. Conclusions The most frequently isolated fungi were Aspergillus, followed by Cryptococcus. Final diagnosis is mainly dependent on pathological examination. Clinical manifestations, imaging features, diagnostic procedures and management are different due to the difference of pathogenic fungi. Satisfactory Results can be obtained by anti-fungal therapy combined with surgical management.

Objective To analyze the pattern of antibiotic resistance in 1 073 strains of Pseudomonas aeruginosa in People's Hospital of Xinjiang Autonomous Region during 2003-2007. Methods Automated microbe analyzer (VITEK32) was used to analyze antibiotic susceptibility by means of GNS drug sensitivity card and Kirty-Bauer method. Results In recent five years, 1 073 strains of P. aeruginosa were isolated from respiratory specimens, most of which were from ICU, respiratory ICU and surgery ICU (57.8%). Among the 16 antibiotics tested, these strains showed the lowest resistance (17.0%) to cefoperazone-sulbactam, followed by meropenem (18.5%), amikacin (19.6%), imipenem (24.2%), cefepime (25.7%), piperacillin-tazobactam (35.7%) and ceftazidime (36.7%). Although the resistance to cefoperazone-sulbactam and ceftazidime was relatively lower, the prevalence of intermediate strains was relatively higher, 15.2% and 12.5% respectively. Conclusions The antibiotic resistance surveillance Results of five consecutive years indicate that P. aeruginosa was one of the most common pathogens in this hospital associated with serious issue of antibiotic resistance.

Objective To investigate the disinfectant-resistant gene qacA in Staphylococcus aureus isolates from the First Affiliated Hhospital of Chongqing Medical University. Methods A total of 126 S. aureus strains were isolated. The minimum inhibitory concentrations (MICs) of 4 representative monovalent and bivalent disinfectants were determined. Polymerase chain reaction (PCR) was employed to analyze the prevalence of qacA gene in these strains. Disk diffusion method was used to identify methicillin-resistant S. aureus (MRSA).Results Of the 126 S. aureus strains, 12 were positive for qacA gene. The prevalence of qacA in these strains was 9.5%. The prevalence of qacA gene in MRSA was 17.3%. Conclusions qacA gene is prevalent in the clinical isolates of S. aureus.

Objective To investigate the antibiotic-resistant gene mecA and the prevalence of Panton-Valentine leukocidin (PVL) gene, toxic shock syndrome toxin (TSST-Ⅰ) gene in S. aureus. Methods A total of 74 S. aureus were collected from clinical specimens. The mecA, PVL and TSST-Ⅰ genes were detected by PCR.Results PVL gene was identified in 22 S. aureus isolates. The prevalence of PVL was 29.7% in S. aureus, 36.6% in MRSA and 21.2% in MSSA. The difference was not statistically significant (P>0.05). The prevalence of MRSA was 55.4% in 74 S. aureus. The prevalence of TSST-Ⅰ gene was 6.8%. TSST-Ⅰ gene was not detected in MSSA.Conclusions MRSA strains show highly resistant to antibiotics. PVL- and TSST-Ⅰ-positive S. aureus are more pathogenic.

Objective To evaluate the efficacy and safety of linezolid in the treatment of severe lung infections caused by methicillin-resistant Staphylococcus aureus (MRSA).Methods Fifteen patients admitted to ICU due to severe lung infection caused by MRSA received linezolid treatment. WBC, lactic acid (LAC), IL-1β, IL-6, and TNF-α levels were measured before and after treatment. Results Clinical efficacy rate was 73.3%. The level of WBC, LAC and inflammatory cytokines decreased significantly after linezolid treatment (P<0.01).Conclusions Linezolid shows good efficacy in the treatment of severe lung infections caused by MRSA.

Objective To investigate the clinical features and prognosis of pulmonary infection at different stages after renal transplantation.Methods Medical records of 61 patients with pulmonary infection after renal transplantation from January 2003 to July 2008 in our hospital were reviewed in this retrospective study. According to stages of infection onset, we divided all patients into two groups, early onset group (43/61, 70.5%, ≤12 months after transplantation) and late onset group (18/61, 29.5%, >12 months after transplantation). Clinical manifestations and prognosis were compared between the two groups.Results In the early onset group, the radiographic manifestation suggested diffuse interstitial changes of bilateral lungs. Combination of anti-infective therapy and early mechanical ventilation was preferred. While in the late onset group, unilateral pulmonary lesions were seen in most cases. More patients showed cardiac and gastrointestinal complications in this group, the mortality of which was much higher. Conclusions Pulmonary infection is a major complication of renal transplantation. The etiology, clinical characteristics and prognosis of infection varies with the stage after transplantation. Effective preventive and therapeutic measures should be applied more vigorously in patients with pulmonary infection, especially early onset ones.