Since the introduction of PCV7 for children, there has been an emergence of IPD caused by virulent clones of non-PCV7 serotypes that has been associated with significant clinical changes and a decrease in antibiotic resistance.

The specificity of the different techniques used to diagnose ventilator-associated pneumonia is still a matter of controversy. To investigate the specificity of endotracheal aspiration (EA), protected specimen brush (PSB), and bronchoalveolar lavage (BAL) quantitative cultures, we studied 27 consecutive mechanically ventilated (MV) patients (> 72 h) without clinical or radiographic evidence of pulmonary infection. Comparing different thresholds for quantitative cultures (from 10(3) through 10(6) CFU/ml), the lowest rate of false positive results was obtained using 10(6) for EA, 10(5) for PSB, and 10(6) for BAL. Using 10(6) CFU/ml for EA, 10(4) CFU/ml for PSB, and 10(5) CFU/ml for BAL as cutoff points, we obtained the following specificities: 85, 85, and 78% for the three techniques, respectively. A bacterial index of 8 was the best threshold to get a low percentage of false positive results for all techniques except for EA (0% for PSB and 12% for BAL). There were reasonable qualitative agreements (PSB versus EA = 58%; BAL versus EA = 69%; and PSB versus BAL = 62%) and poor quantitative correlations between concomitantly isolated microorganisms from the three types of samples. Quantitative cultures of EA, PSB, and BAL may show a considerable percentage of false positive results at the respective cutoff points usually accepted. Increasing the thresholds for quantitative cultures, albeit loosing sensitivity, may rule out better the absence of pulmonary infection in MV patients.

We studied the interrelations between gastric, pharyngeal, proximal, and distal airway bacterial flora in ventilator-associated pneumonia (VAP) on 36 patients with nosocomial pneumonia acquired during mechanical ventilation (MV) and 27 mechanically ventilated control subjects without pulmonary infection. Gastric, pharyngeal, and endotracheal (EA) sampling for quantitative cultures were performed upon all patients, as well as fiberoptic bronchoscopy with protected specimen brush (PSB) sampling. Mean bacterial and fungi colony counts were significantly increased in pharyngeal, EA, and PSB samples in patients with VAP compared with control subjects. The overall increase in colonization was due to gram-positive cocci in all samples. In addition, gram-negative bacilli and fungi mean counts increased significantly in PSB pneumonia samples versus control samples. However, mean gastric colonization was similar in both patients with VAP and control subjects. In the former group there was an increase in coincident microorganisms isolated from gastric, pharyngeal, and EA samples in relation to PSB samples compared with control samples. Among the different quantitative cultures analyzed, only those obtained from EA significantly correlated with PSB cultures in patients with pneumonia (r = 0.67, p = 0.001). In summary, the present study shows that the coincidence between microorganisms isolated in PSB cultures and those from gastric and oropharynx increase in MV patients with pneumonia, indicating that both reservoirs play a key role in the pathogenesis of pneumonia. Conceivably, preventing both gastric and pharyngeal colonization may reduce the incidence of ventilator-associated pneumonia. From all the noninvasive samples studied only endotracheal aspirate cultures were useful for inferring the etiology of some VAP pneumonias.

Among 165 Spanish Haemophilus influenzae isolates with mutations in the ftsI gene (ftsI ؉ ) (2005 to 2007), 73% were ␤-lactamase negative and 26.7% were positive. The proportion of ␤-lactamase-negative isolates to ␤-lactamase-positive isolates was 2:1 to 4:1 in general, versus 1:3 in pediatric hospitals. Among 44 ␤-lactamasepositive strains, 8 strains produced ROB-1 (5 from the pediatric hospital). ␤-Lactamase-positive ftsI ؉ strains were phylogenetically closer than were ␤-lactamase-negative strains.Since previous studies showed that ampicillin-susceptible ␤-lactamase-negative Haemophilus influenzae strains showing an ampicillin MIC of 1 g/ml should be interpreted with caution because they may carry ftsI gene mutations (5), the presence of these mutations in ␤-lactamase-positive strains susceptible to amoxicillin-clavulanic acid exhibiting MICs of 2/1 to 4/2 g/ml can be suspected. The aim of this study was to genotypically and phenotypically characterize (with respect to ␤-lactam susceptibility) H. influenzae isolates with ampicillin MIC of Ն1 g/ml for ␤-lactamase-negative or amoxicillinclavulanic acid MIC of Ն2/1 g/ml for ␤-lactamase-positive strains. Spanish hospitals were contacted with a request for isolates with these susceptibility characteristics that were collected from March 2005 to March 2007. Six hospitals sent isolates that were retested in triplicate, and those showing the required or 1-dilution-lower modal MICs were included. Of the 252 strains received, 199 were recovered and exhibited the susceptibility requirements. Susceptibility to ␤-lactams was determined by microdilution (1). The susceptibility breakpoints considered were Յ1 g/ml for ampicillin, Յ4/2 g/ml for amoxicillin-clavulanic acid, Յ8 g/ml for cefaclor, Յ4 g/ml for cefuroxime, Յ1 g/ml for cefdinir, and Յ2 g/ml for cefotaxime (2). Nonsusceptibility was considered when MICs were above the susceptibility breakpoints. ␤-Lactamase production was determined by the chromogenic cephalosporin test (7).For amplification and sequencing of the ftsI gene, DNA was obtained using the QIAamp DNA kit (Qiagen, Hilden, Germany). PCR amplification of the ftsI, acrR, bla TEM , and bla ROB genes was performed using referenced primers (6,8,9). Strains with mutations in the ftsI gene were genotypically defined as BLNAR (␤-lactamase negative, ampicillin resistant) or BLPACR (␤-lactamase positive, amoxicillin-clavulanic acid resistant) that, when possible, were classified into the groups and subgroups proposed by Dabernat et al. (3) and Ubukata et al. (9). The ClustalW2 program (http://www.ebi.ac.uk) was used to construct phylogenetic trees of a 1,030-bp sequence from the ftsI gene.Of the 199 strains exhibiting the susceptibility requirements, amplification failed in three isolates excluded for further analysis (all were ␤-lactamase negative; two strains had an ampicillin MIC of 2 g/ml and one of 1 g/ml).Of the 196 strains tested, 31 (15.8%) did not present mutation in the ftsI gene, 10 were ␤-lactamase negative, and 21 were ␤-lactamase positive by the chromo...

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