肺隐球菌病20例临床分析

随着免疫受损人群的增加,肺隐球菌病发病率逐渐增加。近年来有关免疫正常人群感染的报道也日益增多。肺隐球菌病临床表现缺乏特异性,影像学表现多样,容易误诊和漏诊。为提高对该病的认识和诊治水平,现对北京大学人民医院2009年至2019年收治的20例肺隐球菌病患者临床资料进行回顾分析。

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 y-hemolysin （hlg）, staphylococcal cassette chromosome mec （SCCmec） type, agr type, and Multilocus Sequence Typinq （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.

Prevalence and characterization of plasmid-mediated blaESBL with their genetic environment in Escherichia coli and Klebsiella pneumoniae in patients with pneumonia

Background The extended spectrum 13-1actamase （ESBL）-producing Escherichia coil （E. coh） and Klebsiella pneumoniae （K. pneumoniae） are the major pathogens causing pneumonia and have a significant impact on the clinical course. Limited data exist on molecular characterization of ESBL-producing E. coli and K. pneumoniae that cause pneumonia. The aim of this study was to investigate the comprehensive multilevel characteristics of E. coil and K. pneumoniae causing pneumonia in China for the first time.

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 nosocomialacquired 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 13-1actamase 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. baumanfi 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-3-1a was found in 23 strains, and the aac-6＂lb gene in 19 strains, aac-3-1a and aac-6＂lb genes hibernated in three A. baumanfi 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.

Serological and molecular capsular typing, antibiotic susceptibility and multilocus sequence typing of Streptococcuspneumoniae isolates from invasive and non-invasive infections

Background Streptococcus pneumoniae （S.pneumoniae） is a major causative agent of severe infections,including sepsis,pneumonia,meningitis,and otitis media,and has become a major public health concern.We report the pneumococcal serotype and sequence type （ST） distribution,and antimicrobial resistance of 39 S.pneumoniae strains from seven hospitals in China.Methods Blood/cerebrospinal fluid （CSF） and sputum isolates from patients were analyzed to determine S.pneumoniae serotypes by polymerase chain reaction （PCR） and the Neufeld Quellung reaction,the multilocus sequence types （MLST） by PCR and sequencing,and susceptibility to antimicrobial agents by the VITEK Gram Positive Susceptibility Card.Results A total of 39 isolates were collected including 21 blood/CSF and 18 sputum isolates.Conventional serotyping by the Quellung reaction required 749 reactions.In contrast,PCR based typing needed only 106 PCR reactions.The most frequent serotypes from the blood/CSF isolates were 14 （38.1%）,19A （14.3%）,23F （9.5%）,and 18C （9.5%）.In the sputum isolates the most frequent serotypes were 19F （33.3%）,23F （16.7%）,19A （11.1%）,and 3 （11.1%）.The incidence of penicillin resistance in the blood/CSF and sputum isolates was 66.7% and 55.6%,respectively.Statistical analysis showed that patients ≤5 years old had a higher resistance to penicillin when they compared with the patients ≥65 years old （P=0.011）.Serotypes 14,19A and 19F were significantly associated with penicillin resistance （P 〈0.001）.ST320,ST271,and ST876 isolates showed high resistant rates to several antibiotics including penicillin （P=0.006）.All of the isolates of serotype 19A were resistant to both penicillin and erythromycin,and they were all multi-drug resistant （MDR） isolates.Conclusions The specificity and sensitivity of multiplexPCR are good,and this method represents a substantial savings of time and money,and can be widely used in the laboratory and clinical practice.Data from this research showed an extremely high prevalence of penicillin resistance and an increasing prevalence of multi-drug resistant （MDR） rate in S.pneumoniae.A distinctive emergence of serotype 19A was observed which was also associated with the increasing prevalence of antimicrobial resistance.Therefore,nationwide surveillance of pneumococcal resistance and serotypes is strongly warranted.

Diffuse pulmonary lymphangiomatosis： a case report with literature review

Diffuse pulmonary lymphangiomatosis （DPL） is a rare disease that is characterized by diffuse proliferation of abnormal pulmonary lymphatic channels. DPL occurs mostly in children and young adults and often undergoes a progressive clinical course, eventually causing deterioration of the lung. Both the clinical diagnosis and treatment of DPL remain a challenge. Here, we report a case of DPL in a 53-year-old Chinese woman with comprehensive investigations including pulmonary function tests, computer tomography （CT）, bronchoscopy and histological examination of the lung biopsy, and review the literature.

Potential role of human visceral pleura in pleural fluid turnover

With continuing advanced research into pleural fluid turnover, the majority of scientists hold the view that pleural fluid is derived from the microvessels in parietal pleura and drained via parietal lymphatic vessels which empty into systemic veins. The lymphatic vessels that contribute to the pulmonary lymphatic circulation originate in the subpleural connective tissue, not directly from the visceral mesothelium. Therefore, according to the current point of view, pleural effusion absorption through the visceral pleural is normally neclligible and visceral pleura,

Identification of pathogen in community-acquired pneumonia and its beyond

Lower respiratory tract infections （LRTI）, such as community-acquired pneumonia （CAP） and influenza, still are the major leading causes of morbidity and mortality, and the third most common cause of death globally although it fluctuates among different stratified countries.1 As reported by WHO in 2008,