ABSTRACT
To study the risk factors and the clinical characteristics of non-tuberculous mycobacterial (NTM) pulmonary diseases in patients with mechanical ventilation. Methods Retrospective survey was carried out in the patients with mechanical ventilation who combined with NTM pulmonary disease admitted to intensive care unit (ICU) of the First Affiliated Hospital of Guangzhou Medical University from May 2016 to May 2019. The general information, basic diseases, symptoms, signs, biochemical examinations, acid-fast stain test, mycobacterium culture and strain identification results, and chest CT data were collected to summarize the clinical characteristics of patients with mechanical ventilation combined with NTM pulmonary disease. Results There were 12 patients with mechanical ventilation combined with NTM pulmonary disease, 6 males and 6 females, 37-82 years old, with an average age of 65 years. In these 12 cases, patients with cancer (lung cancer were 4 cases, mediastinal tumor was 1 case) and after lung transplantation (use of anti-rejection drugs at the same time) were 5 and 2 respectively. Patients with at least 3 underlying diseases [included hypertension, diabetes, coronary heart disease, chronic obstructive pulmonary disease (COPD), bronchiectasis, chronic renal insufficiency] were 5. Clinical symptoms of the 12 cases were non-specific. The CT findings were not characteristic, including nodules, patchy infiltrations and fibrous streak. Pleural effusion was common among these subjects but nodular bronchiectatic patterns were absence. Routine laboratory indicators of bacterial infection were non-specific. But the number of lymphocytes of all cases decreased. Mycobacteria cultures were positive with the rapid growth of mycobacteria in these 12 cases. Mycobacterium avium (4 cases), Mycobacterium chelonae (4 cases), Mycobacterium chelonae-abscessus complex (2 cases) and Mycobacterium intracellulare (2 cases) were isolated. Anti-NTM therapy was given to the patients when the acid-fast staining test of their airway secretion was positive and the TB-DNA test was negative, including oral levofloxacin and clarithromycin. Finally, all patients were successfully weaned and discharged from ICU. Conclusions The clinical symptoms of NTM patients with pulmonary disease are non-specific, and the imaging features of chest CT are varied. Patients with mechanical ventilation in ICU, who have the risk of immune dysfunction or underlying structural lung diseases, and who have difficult controlled lung infection, accompanied by pleural effusion and with decreased lymphocytes, should be aware that pneumonia may be caused by non-tuberculous mycobacteria.
ABSTRACT
Objective To explore the causes of rising carbapenem resistance in Acinetobacter baumannii isolates by analysis of the carbapenemase genotypes in A .baumannii .Methods WHONET 5 .4 was used to analyze the changing resistance profile of A .baumannii isolates over years .A total of 320 carbapenem‐resistant A .baumannii isolates were collected from the patients in an intensive care unit from January 2008 to December 2012 .All strains were identified and tested by VITEK 2 for their susceptibility .The metallo‐β‐lactamases genes and OXA carbapenemase genes were investigated by polymerase chain reaction . Results The resistance rate of A .baumannii isolates to meropenem and imipenem increased rapidly from 10 .8% to 80 .4% and from 13 .5% to 83 .5% during the period from 2008 and 2012 .The prevalence of blaOXA‐23and ISAba1‐associated blaOXA‐23genes increased from 25 .0% to 97 .1% .No metallo‐β‐lactamase encoding genes were detected .Conclusions Our results indicate that the rising carbapenem resistance in the A . baumannii isolates in our intensive care unit may be associated with the high prevalence of blaOXA‐23 and IS A ba1‐associated blaOXA‐23 genes .
ABSTRACT
Objective To evaluate the in vitro antimicrobial activity of piperacillin-sulbactam against clinical isolates of non-fermentative bacilli isolated from common infections. Methods Microdilution was employed to study the antimicrobial resistance. Results A total of 770 strains were collected from 6 hospitals in Guangzhou, including Pseudomonas aeruginosa, Acinetobacter baumannii, Stenotrophomonas maltophilia , Burkholderia cepacia , Flavobacterium , and Alcaligenes. Compared with other β-lactams,piperacillin-sulbactam displayed the highest activity against all the isolates of P. aeruginosa, especially for imipenem non-sensitive isolates, with the susceptibility of 71.9% and 55.8%, respectively. Piperacillinsulbactam and cefoperazone-sulbactam kept good activity against imipenem sensitive isolates of A. baumannii,with the susceptibility of 71.0% and 73. 0%, respectively. For the strains of Burkholderia cepacia, 69% strains exhibited minimal inhibitory concentration (MIC) of ≤ 16 mg/L for piperacillin-sulbactam. For the strains of Flavobacterium, and Alcaligenes, piperacillin-sulbactam also had excellent activity, with the susceptibility of 70. 2% and 94. 4%, respectively. Conclusion Piperacillin-sulbactam exhibits good activity again non-fermentative bacilli, especial for imipenem non-sensitive isolates of P. aeruginosa.