[Atypical pathogens in adult patients admitted with community-acquired pneumonia].

OBJECTIVE: To investigate the current status of atypical pathogen associated infections in community-acquired pneumonia (CAP) in adults, and their clinical attributes. METHODS: Clinical data, sputum specimens from acute phase, and paired sera from acute- and convalescent-phases of CAP in 153 adult patients were collected from May 2005 to May 2008 in multiple medical centers. Chlamydia pneumoniae (Cpn) IgG antibody, and Legionella pneumophila (LP) mixed IgG, IgA and IgM antibodies were determined by indirect immuno-fluorescent assay. Mycoplasma pneumoniae (Mpn) mixed IgG, IgA and IgM antibodies were determined by passive agglutination assay. All the sputum specimens were routinely cultured for bacterial isolation. RESULTS: Fifty-two (34%) out of the 153 cases were diagnosed as atypical CAP per the paired serum-antibody assay. Forty-seven of the 52 atypical CAP cases were infected by one atypical pathogen, 38 with Cpn, 4 with Mpn, and 5 with LP, while 5 out of the 52 atypical CAP cases were infected by 2 pathogens, Cpn and Mpnin 2, Cpn and LP in 3 cases. Eleven cases (21.2%) out of the 52 patients with atypical pneumonia were complicated with bacterial infection. Except peripheral white blood count was significant increased in the group of typical (bacterial only) pneumonia (WBC > 10 × 109)/L, P = 0.03), all the other clinical parameters did not show statistically significant difference between the typical and the atypical pneumonia groups. CONCLUSIONS: Our data suggest that Chlamydia pneumoniae, Mycoplasma pneumoniae and Legionella pneumophila are common pathogens of adult CAP. Chlamydia pneumoniae might be the most frequent atypical pathogen associated with atypical CAP.

[The effect of murine interferon-gamma transgene expression on bleomycin-induced pulmonary fibrosis in mice].

OBJECTIVE: To investigate the effect of murine interferon-gamma (IFN-gamma) transgene expression on bleomycin-induced pulmonary fibrosis in mice. METHODS: 6 - 8 week aged pathogen-free male ICR mice were treated with bleomycin (3 mg/kg weight in 70 micro l) by intranasal instillation on day 0 in the model group. Adenoviral vector with murine IFN-gamma cDNA (AdCMVmIFN-gamma) 5 x 10(8) plague forming unit (pfu) was administrated via nastril instillation 48 h before bleomycin treatment in the preventive therapeutic group, but 72 h after bleomycin treatment in the therapeutic group. Mice treated with a same volume of normal saline (NS) and a same dosage of sham recombinant adenoviruses (AdCMVNull) served as controls. The animals were weighted on day 0, 7, 14, and sacrificed on day 14. Bronchial alveolar lavage fluid (BALF) and lungs were recovered. The right lung was stained with either hematoxylin-eosin or masson. The left lung was weighted, and its content of hydroxyproline (HYP) was measured by HCl acid hydrosis method. The IFN-gamma concentration in BALF was determined with enzyme-linked immunosorbent assay. RESULTS: The concentrations of IFN-gamma in BALF from the AdCMVmIFN-gamma treated groups were remarkably increased, (21,250 +/- 6,497) pg/ml and (21,000 +/- 5,451) pg/ml in the IFN-gamma transgenetic preventive therapeutic group and the therapeutic group respectively. IFN-gamma was undetectable in BALF from other groups. Mice in the two groups treated with AdCMVmIFN-gamma had statistically significant weight loss (P < 0.05), higher HYP content (P < 0.05), and tended to have more severe alveolitis and pulmonary fibrosis (P = 0.07) as compared with those in other groups. CONCLUSIONS: (1) mIFN-gamma could be overexpressed in airway and alveolar epithelium by locally administrated AdCMVmIFN-gamma. (2) Early mIFN-gamma transgene expression via adenoviral vector in this bleomycin model aggravated alveolitis and fibrosis to some degree.

Preliminary molecular epidemiology of the Staphylococcus aureus in lower respiratory tract infections: a multicenter study in China.

BACKGROUND: Staphylococcus aureus (S. aureus) remains as an important microbial pathogen resulting in community and nosocomial acquired infections with significant morbidity and mortality. Few reports for S. aureus in lower respiratory tract infections (LRTIs) have been documented. The aim of this study was to explore the molecular epidemiology of S. aureus in LRTIs in China. METHODS: A multicenter study of the molecular epidemiology of S. aureus in LRTIs was conducted in 21 hospitals in Beijing, Shanghai and twelve other provinces from November 2007 to February 2009. All the collected S. aureus strains were classified as minimum inhibitory concentration (MIC), mecA gene, virulence genes Panton-Valentine Leukocidin (PVL) and γ-hemolysin (hlg), staphylococcal cassette chromosome mec (SCCmec) type, agr type, and Multilocus Sequence Typing (MLST). RESULTS: Totally, nine methicillin-sensitive S. aureus (MSSA) and 29 methicillin-resistant S. aureus (MRSA) strains were isolated after culture from a total of 2829 sputums or bronchoalveolar lavages. The majority of MRSA strains (22/29) had a MIC value of ≥ 512 µg/ml for cefoxitin. The mecA gene acting as the conservative gene was carried by all MRSA strains. PVL genes were detected in only one S. aureus strain (2.63%, 1/38). The hlg gene was detected in almost the all S. aureus (100% in MSSA and 96.56% in MRSA strains). About 75.86% of MRSA strains carried SCCmec III. Agr type 1 was predominant (78.95%) among the identified three agr types (agr types 1, 2, and 3). Totally, ten sequence type (ST) of S. aureus strains were detected. A new sequence type (ST1445) was found besides confirming ST239 as the major sequence type (60.53%). A dendrogram generated from our own MLST database showed all the bootstrap values ≤ 50%. CONCLUSION: Our preliminary epidemiology data show SCCmec III, ST239 and agr type 1 of S. aureus as the predominant strains in LRTIs in Mainland of China.

Drug-resistant genes carried by Acinetobacter baumanii isolated from patients with lower respiratory tract infection.

BACKGROUND: Acinetobacter baumanii (A. baumanii ) remains an important microbial pathogen resulting in nosocomial acquired infections with significant morbidity and mortality. The mechanism by which nosocomial bacteria, like A. baumanii, attain multidrug resistance to antibiotics is of considerable interest. The aim in this study was to investigate the spread status of antibiotic resistance genes, such as multiple ß-lactamase genes and aminoglycoside-modifying enzyme genes, from A. baumanii strains isolated from patients with lower respiratory tract infections (LRTIs). METHODS: Two thousand six hundred and ninety-eight sputum or the bronchoalveolar lavage samples from inpatients with LRTIs were collected in 21 hospitals in the mainland of China from November 2007 to February 2009. All samples were routinely inoculated. The isolated bacterial strains and their susceptibility were analyzed via VITEK-2 expert system. Several kinds of antibiotic resistant genes were further differentiated via polymerase chain reaction and sequencing methods. RESULTS: Totally, 39 A. baumanii strains were isolated from 2698 sputum or bronchoalveolar lavage samples. There was not only a high resistant rate of the isolated A. baumanii strains to ampicillin and first- and second-generation cephalosporins (94.87%, 100% and 97.44%, respectively), but also to the third-generation cephalosporins (ceftriaxone at 92.31%, ceftazidine at 51.28%) and imipenem (43.59%) as well. The lowest antibiotic resistance rate of 20.51% was found to amikacin. The OXA-23 gene was identified in 17 strains of A. baumanii, and the AmpC gene in 23 strains. The TEM-1 gene was carried in 15 strains. PER-1 and SHV-2 genes were detected in two different strains. Aminoglycoside-modifying enzyme gene aac-3-Ia was found in 23 strains, and the aac-6'-Ib gene in 19 strains. aac-3-Ia and aac-6'-Ib genes hibernated in three A. baumanii strains that showed no drug-resistant phenotype. CONCLUSIONS: A. baumanii can carry multiple drug-resistant genes at the same time and result in multi-drug resistance. Aminoglycoside-modifying enzyme genes could be hibernating in aminoglycoside sensitive strains without expressing their phenotype.

[Effects of injection of Huangqi injectio into Zusanli (ST 36) on immune function in the patient of schizophrenia].

OBJECTIVE: To study on effects of injection of Huangqi Injectio into Zusanli (ST 36) on the hospital infection and immune function in the patient of schizophrenia. METHODS: Thirty inpatients of chronic schizophrenia were treated with injection of Huangqi Injectio into bilateral Zusanli (ST 36), 2 mL each point, thrice each week, for 8 weeks. Relative immune indexes and the hospital infection were investigated. RESULTS: The hospital infection and the sub-infection were 4 cases (13.3%), 7 cases-times (23.3%) in the injection group; and 9 cases (15.0%), 19 cases-times (31.7%) in the control group, respectively, with no significant difference between the two groups (P>0.05). The drug-administration duration was 7.77 days/case and 11.87 days/case in the two groups, respectively (P<0.01). In the injection group, as compared with that of last 3 years the duration was 7.77 days/case and 14.08 days/case (P<0.01). IgG, IgA, IgM and T-cell subgroups did not have significant changes, but there was the most different value before and after injection in SIL-2R of the no-infection group, and the longer the drug administration duration, the smaller the different values. CONCLUSION: Injection of Huangqi Injectio into Zusanli (ST 36) has definite effect for prevention of the hospital infection in inpatients of chronic schizophrenia, and SIL-2R is a valuable index for investigation of the hospital of infection.