Detection of the etiological agents of hospital-acquired pneumonia - validity and comparison of different types of biological sample collection: a prospective, observational study in intensive care patients.

BACKGROUND: There is still a lack of evidence as to which method of biological sample collection is optimal for identifying bacterial pathogens causing hospital-acquired pneumonia (HAP). Much effort has been made to find an easy and valid approach to be used in clinical practice. METHODS: The primary endpoint of this prospective, observational study was to determine the predictive value of oropharyngeal swab (OS) and gastric aspiration (GA) as simple and non-invasive methods for diagnosing HAP. Their efficacy was compared to endotracheal aspiration (ETA) and protected specimen brushing (PSB), the standard methods approved for HAP diagnosis. RESULTS: Initially, 56 patients were enrolled. Significant amounts of bacterial pathogens were detected in 48 patients (79 isolates) in Round A and in 39 patients (45 isolates) in Round B (after 72 hours). The sensitivity rates were: ETA 98%, PSB 31%, OS 64% and GA 67% in Round A and ETA 87%, PSB 32%, OS 74% and GA 42% in Round B. Strains of 12 bacterial species were identified in the samples. The three most common etiological agents (both rounds together) were Klebsiella pneumoniae (23.7%), Burkholderia multivorans (21.1%) and Pseudomonas aeruginosa (15.8%). CONCLUSIONS: Blind ETA is an optimum method for obtaining biological samples for identification of etiological agents causing HAP in intubated patients. Microbial etiological agents were more frequently detected in ETA samples than in those collected by PSB. If ETA/PSB results are negative, samples may be collected by OS and/or GA as these techniques followed ETA in terms of the frequency of pathogen detection.

An outbreak of Burkholderia multivorans beyond cystic fibrosis patients.

Strains of the Burkholderia cepacia complex (Bcc) are opportunistic pathogens capable of causing serious infection in cystic fibrosis patients. Recently we identified a suspected outbreak of infection with Bcc strains at the University Hospital Olomouc. Seventy-four Bcc strains were isolated from 52 patients, most of whom (N = 48) did not suffer from cystic fibrosis. Most frequently (N = 46) Burkholderia multivorans was isolated and 24 (52.2%) of these strains were clonal. Fifteen of these strains were isolated from intensive care patients, five of whom died from hospital-acquired pneumonia. B. multivorans can cause serious outbreaks of infection beyond cystic fibrosis sufferers.

[Detection of Burkholderia cepacia complex strains in the University Hospital Olomouc]. / Záchyt kmenu Burkholderia cepacia komplex ve Fakultní nemocnici Olomouc.

BACKGROUND: The aim was to assess the epidemiology of Burkholderia cepacia complex strains isolated at the Department of Microbiology, Faculty of Medicine and Dentistry, Palacky University and University Hospital Olomouc, determine the most frequent strains and confirm or rule out potential clonal spread of the strains. MATERIAL AND METHODS: Over a period of eight months, all strains classified as Burkholderia cepacia complex were collected. Susceptibility to selected antimicrobial agents was determined and adequate molecular genetic methods were used to assess their genetic relationship. RESULTS: A total of 52 isolates were tested, with the most frequent (88.5 %) being genomovar II (Burkholderia multivorans). More than 46 % of them were genetically related; 58.3 % of them were detected in intensive care units. All isolates were highly resistant to antimicrobial agents. In four cases, deaths associated with Burkholderia multivorans infection were reported. CONCLUSION: It may be assumed that genetically related strains of Burkholderia multivorans spread from the hospital setting. As yet, the source of infection has not been determined and further investigations are needed.