Emilio Pérez-Trallero

Antimicrobial Susceptibilities of 1,684 Streptococcus pneumoniae and 2,039 Streptococcus pyogenes Isolates and Their Ecological Relationships: Results of a 1-Year (1998–1999) Multicenter Surveillance Study in Spain

ABSTRACT A nationwide multicenter susceptibility surveillance study which included 1,684 Streptococcus pneumoniae and 2,039S. pyogenes isolates was carried out over 1 year in order to assess the current resistance patterns for the two most important gram-positive microorganisms responsible for community-acquired infections in Spain. Susceptibility testing was done by a broth microdilution method according to National Committee for Clinical Laboratory Standards M100-S10 interpretative criteria. ForS. pneumoniae, the prevalences of highly resistant strains were 5% for amoxicillin and amoxicillin-clavulanic acid; 7% for cefotaxime; 22% for penicillin; 31% for cefuroxime; 35% for erythromycin, clarithromycin, and azithromycin; and 42% for cefaclor. For S. pyogenes, the prevalence of erythromycin resistance was 20%. Efflux was encountered in 90% of S. pyogenes and 5% of S. pneumoniae isolates that exhibited erythromycin resistance. Erythromycin resistance was associated with clarithromycin and azithromycin in both species, regardless of phenotype. Despite the different nature of the mechanisms of resistance, a positive correlation (r = 0.612) between the two species in the prevalence of erythromycin resistance was found in site-by-site comparisons, suggesting some kind of link with antibiotic consumption. Regarding ciprofloxacin, the MIC was ≥4 μg/ml for 7% of S. pneumoniae and 3.5% of S. pyogenes isolates. Ciprofloxacin resistance (MIC, ≥4 μg/ml) was significantly (P < 0.05) associated with macrolide resistance in both S. pyogenes and S. pneumoniae and with penicillin nonsusceptibility in S. pneumoniae.

Human Bocavirus, a Respiratory and Enteric Virus

In Spain, human bocavirus (HBoV) was detected in 48 (9.1%) of 527 children with gastroenteritis at similar frequency as for children with respiratory illness (40/520, 7.7%). Fecal excretion adds new concern about the transmission of HBoV. To our knowledge, this report is the first to document HBoV in human feces.

Geographical and Ecological Analysis of Resistance, Coresistance, and Coupled Resistance to Antimicrobials in Respiratory Pathogenic Bacteria in Spain

ABSTRACT A multicenter susceptibility surveillance (the S.A.U.C.E. project) including 2,721 Streptococcus pneumoniae, 3,174 Streptococcus pyogenes, and 2,645 Haemophilus influenzae consecutive isolates was carried out in 25 hospitals all over Spain from November 2001 to October 2002 to evaluate the current epidemiology of resistance of the main bacteria involved in community-acquired respiratory tract infections. Susceptibility testing was performed in a single centralized laboratory by a broth microdilution method. The prevalence of resistant S. pneumoniae strains was 0.4% for cefotaxime, 4.4% for amoxicillin and amoxicillin-clavulanic acid, 25.6% for cefuroxime-axetil, 34.5% for erythromycin, clarithromycin, and azithromycin, and 36.0% for cefaclor. Phenotypes of resistance to erythromycin were MLSB (macrolide-lincosamide-streptogramin B) in 89.9% (gene ermB) and M (macrolide) in 9.7% of cases (gene mefA). No strain harbored both genes simultaneously. Serotypes 19, 6, 23, 14, and 3 were the most prevalent, accounting for 54.6% of the total isolates. Resistance to macrolides seems to be the most alarming point, since among penicillin-susceptible isolates it reached 15.1% compared to 55.8% among penicillin-resistant strains. Geographically, a number of regions had rates of erythromycin resistance above 40% (even higher in children). Resistance to erythromycin was also high in S. pyogenes isolates: mean regional 33.2%, beta-lactamase-producing H. influenzae were 20%, whereas 4.4% had a beta-lactamase-negative, ampicillin-resistant phenotype. We highlight the importance of different geographical frequencies of coresistance (associations of resistance to different drugs within the same species) and coupled resistance (association of resistance between different species) probably resulting from different local coselective events.

Antimicrobial Resistance among Respiratory Pathogens in Spain: Latest Data and Changes over 11 Years (1996-1997 to 2006-2007)

ABSTRACT A nationwide multicenter susceptibility surveillance study (Susceptibility to the Antimicrobials Used in the Community in España [SAUCE] project), SAUCE-4, including 2,559 Streptococcus pneumoniae, 2,287 Streptococcus pyogenes, and 2,736 Haemophilus influenzae isolates was carried out from May 2006 to June 2007 in 34 Spanish hospitals. Then, the results from SAUCE-4 were compared to those from all three previous SAUCE studies carried out in 1996-1997, 1998-1999, and 2001-2002 to assess the temporal trends in resistance and the phenotypes of resistance over the 11-year period. In SAUCE-4, on the basis of the CLSI breakpoints, penicillin (parenteral, nonmeningitis breakpoint) and cefotaxime were the antimicrobials that were the most active against S. pneumoniae (99.8% and 99.6%, respectively). Only 0.9% of isolates had a penicillin MIC of ≥2 μg/ml. In S. pyogenes, nonsusceptibility to erythromycin was observed in 19.4% of isolates. Among the H. influenzae isolates, a β-lactamase-positive prevalence of 15.7% was found. A statistically significant temporal decreasing trend over the 11-year period was observed for nonsusceptibility (from 60.0% to 22.9%) and resistance (from 36.5% to 0.9%) to penicillin and for the proportion of erythromycin-resistant isolates of S. pneumoniae of the macrolide-lincosamide-streptogramin B (MLSB) phenotype (from 98.4% to 81.3%). A similar trend was observed for the prevalence of ampicillin resistance (from 37.6% to 16.1%), β-lactamase production (from 25.7% to 15.7%), and β-lactamase-negative ampicillin resistance (BLNAR) in H. influenzae (from 13.5% to 0.7%). Among erythromycin-resistant isolates of S. pyogenes, a significant increasing trend in the prevalence of MLSB was observed (from 7.0% to 35.5%). SAUCE-4 confirms a generalized decline in the resistance of the main respiratory pathogens to the antimicrobials as well as a shift in their resistance phenotypes.

Fluoroquinolone and macrolide treatment failure in pneumococcal pneumonia and selection of multidrug-resistant isolates.

Streptococcus pneumoniae serotype 3, isolated from a penicillin-allergic patient and initially susceptible to fluoroquinolones, macrolides, lincosamides, quinupristin-dalfopristin, and telithromycin, became resistant to all these drugs during treatment. Mutations in the parC and gyrA and in the 23S rRNA and the ribosomal protein L22 genes were detected in the resistant isolates.

Phenotypic and Genotypic Characterization of Streptococcus pyogenes Isolates Displaying the MLSB Phenotype of Macrolide Resistance in Spain, 1999 to 2005

ABSTRACT The aim of this study was to describe the genetic characteristics of Streptococcus pyogenes showing the MLSB phenotype of macrolide resistance from 1999 to 2005 in Spain and to highlight the substantial increase in these isolates in the last few years. The antimicrobial susceptibilities of 17,232 group A streptococci isolated from Madrid and Gipuzkoa from 1999 to 2005 were studied. The presence of the resistance genes ermA, ermB, mef, tetM, and tetO and the presence of the intTn and xis genes of the Tn916-Tn1545 transposon family were studied in a sample of 739 MLSB-resistant isolates. The epidemiological relationships among these isolates were analyzed by emm typing, T typing, and multilocus sequence typing. Erythromycin resistance was found in 21.3% of the isolates analyzed (annual variation of 14.3% to 28.9%). Until 2003, most erythromycin-resistant isolates showed the M phenotype, but in 2004 and 2005, about 50% of isolates showed the MLSB phenotype. Among the MLSB-resistant isolates studied, 16 clones were identified. The most prevalent clone was a strange emm11/T11/ST403 clone with a null yqiL allele. All but one of the 463 emm11/T11/ST403 isolates carried the ermB, tetM, intTn, and xis genes. The second most prevalent MLSB-resistant clone was emm28/T28/ST52, which comprised two subclones: one bacitracin-resistant, tetracycline-susceptible subclone carrying the ermB gene (n = 115) and another bacitracin-susceptible, tetracycline-resistant subclone carrying the ermB and tetM genes (n = 33). The rapid diffusion of these two clones, and especially of emm11/T11/ST403, caused the large increase in MLSB-resistant S. pyogenes isolates in Spain, suggesting a potential ability for international dissemination.

Fluoroquinolone Resistance in Penicillin-resistant Streptococcus pneumoniae Clones, Spain

Of 75 clones isolated, 1 had ciprofloxacin efflux, and 74 had mutations at the DNA topoisomerase gene.

Falling Incidence and Prevalence of Hepatitis a in Northern Spain

The prevalence of hepatitis A virus antibodies was studied using a commercial ELISA method. 2,214 subjects were included, 1,211 in 1992 and 1,003 during 1986-87. In 1992 the seroprevalence rates among subjects 1-9, 10-19, 20-29 and 30-39 years old were 2.4%, 21%, 57.6% and 87.5% respectively, as compared with 7.7%, 37.9%, 80.6% and 98.1% respectively, in a similar group of subjects studied 5 years earlier (p < or = 0.001). The reported number viral hepatitis cases declined from 35.0 per 100,000 people in 1984 to 8.9 per 100,000 in 1992. Concurrently, the age when contracting the disease rose. The mean age for patients acquiring hepatitis A was 15.5 in 1986-88 and 20.1 in 1991-92. The decline in incidence and prevalence of HAV infection indicates a progressive and continuous decrease in HAV circulation in this geographical area.

Factors impacting on length of stay and mortality of community-acquired pneumonia

A 1-year retrospective multicentre study was performed to identify factors influencing hospital length of stay (LOS) and mortality of patients (n = 3233) admitted to hospital because of community-acquired pneumonia (CAP). Pneumonia severity index (PSI) high-risk classes (IV and V), positive blood culture, admission to an intensive care unit (ICU), multi-lobar involvement and alcohol consumption were associated independently with prolonged LOS. Tobacco smoking was associated with a reduced LOS. The LOS varied markedly among centres. Only PSI high-risk class, admission to ICU and multi-lobar involvement were associated with early, late and global mortality. Positive blood cultures, antimicrobial therapy according to treatment guidelines and the establishment of an aetiological diagnosis were linked to reduced late and global mortality. These data suggest that early mortality associated with CAP is highly dependent on the clinical status of the patient at presentation. Conversely, late mortality seems to be associated more closely with clinical management factors; hence, an aetiological diagnosis and compliance with appropriate therapeutic guidelines have a significant influence on outcome.

Non-endoscopic method to obtain Helicobacter pylori for culture

A sampling method to collect samples for Helicobacter pylori culture that is easier than endoscopy would be useful. We used a capsule attached to a highly absorbent nylon string, which is swallowed to obtain gastric secretions. Antral biopsy and string specimens, sequentially obtained from 36 adults with clinically suspected ulcer or gastric disease were cultured. 9 (25%) patients were negative in both tests; 18 (50%) were positive by both methods; 6 (17%) were biopsy positive and string-test negative; and 3 (8%) were biopsy negative and string-test positive. The new test is useful, simple, and causes little discomfort.