subject of attention objective: To investigate the character of oropharyngeal and cutaneous commensal microorganisms (OCCs) as a cause of ventilator-associated pneumonia (VAP).

Design: Retrospective analysis of the medical and microbiological records.

Setting: individual medical-surgical ICU.

Patients: All VAP episodes recorded during a 10-year period were reviewed. All patients with suspected VAP underwent bronchoscopy with protected-specimen brush (PSB) sampling and BAL before any change in antibiotic therapy was made. OCC-VAP was defined as VAP with significant vegetation in quantitative cultures (PSB yielded [greater than or equal to] [10sup3] cfu/mL and/or BAL yielded [greater than or equal to] [10sup4] cfu/mL) of OCC sole Three experts reviewed the episodes. Expos patients (ie, those with OCC-VAP) and unexpos patients (ie, patients without VAP) matched onward condition severity at ICU admission and mechanical ventilation duration were compared.

Results: Twenty-nine episodes in 28 patients with [greater than or equal to] [10sup4] cfu/mL OCC in BAL fluid and/or [greater than or equal to] [10sup3] cfu/mL OCC in PSB specimens were set up All patients in these episodes had fresh radiologic lung infiltrates, with 26 episodes involving feculent tracheal aspirates, 23 episodes involving temperatures [greater than or equal to] 385[degrees]C and 18 episodes involving [greater than or equal to] 11000 leukocytes/[micro]L. The main OCC construct were non-[beta]-hemolytic Streptococcus spp (n = 12) Neisseria spp (n = 7) and coagulase-negative Staphylococcus spp (n = 6) Other possible reasons for excitement and the presence of recently made known chest infiltrates were found in 20 and 17 patients, respectively. Histologic evidence of pneumonia was institute in 2 of the 10 patients who died. The three prompts agreed on the diagnosis for 23 patients. In the OCC-VAP assign places to only, the mean ([+ or -] SD) logistic organ dysfunction (LOD) scores increased significantly (LOD score, 2 [+ or -] 4; p = 0008) during the 3 days before bronchoscopy and ICU stay duration was longer than in the unexpos assign places to The exposed/unexposed study found no difference in mortality.

Conclusion: OCC may behave like classic nosocomial pathogens in critically ill patients.

first note of the scale words: BAL; coagulase-negative staphylococci; Neisseria spp; nosocomial infection; protected-specimen brush; Streptococcus epidermidis; Streptococcus spp; ventilator-associated pneumonia

Abbreviations: CGN = coagulase-negative Staphylococcus; CI = confidence interval; CPIS = clinical pulmonary infection score; ICO = intracellular organism; IMV = invasive mechanical ventilation; LOD = logistic organ dysfunction score; MIC = minimum inhibitory concentration; OCC = oropharyngeal or cutaneous commensal microorganism; OR = left over s ratio; PSB = protected-specimen brush; SAPS = simplified acute physiology score; VAP = ventilator-associated pneumonia

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The diagnosis of ventilator-associated pneumonia (VAP) is oftentimes difficult because many other conditions can make sepsis and new lung infiltrates in critically ill patients. (12) Significant numbers of a nosocomial pathogen in quantitative cultivations of bronchial specimens convert a suspicion of VAP to a near certainty. A protected-specimen brush (PSB) improvement showing at least [10.sup.3] cfu/mL a positive issue of a BAL fluid smear, or a BAL fluid agriculture with at least [10.sup.4] cfu/mL is specific for VAP in patients without latter changes in antimicrobial therapy. (23)

The organisms greatest in number often responsible for VAP are methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, and Enterobacteriaceae. In early-onset VAP, Streptococcus pneumoniae, Haemophilus influenzae, and methicillin-sensitive s aureus are causative pathogens.

Significant germination of oropharyngeal or cutaneous commensal microorganisms (OCCs) in quantitative improvements of distal bronchial specimens are more difficult to interpret. Because their virulence is gentle OCCs are widely believed to be nonpathogenic. (4) The nearness in distal bronchial specimens of microorganisms of the like kind as Neisseria spp, Corynebacterium spp or coagulase-negative Staphylococcus (CGNS) is ofttimes considered to indicate lung colonization or specimen contamination.

However, there is ample evidence that these same species can bring into view various infections in both immunocompetent and immunocompromised legions (5-10) Numerous studies (11,12) have shown that critically ill patients have tangle deficiencies in both cellular and humoral immunity. Moreover, OCC have been raise in lung cultures in postmortem studies. (1314) These data may ready ICU physicians to treat patients with OCC in distal bronchial specimens.

chiefly studies investigating the potential character of OCCs as lung pathogens (15-21) have reported the rate of OCC recuperation in series of patients with VAP. The meaning of significant shooting in quantitative cultures of OCC has been neither investigated in extent nor discussed in reviews or consensus conversations about VAP. (22,23)

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