Nasopharyngeal carriage of Streptococcus pneumoniae among children in an urban setting in Brazil prior to PCV10 introduction.

Information on pneumococcal carriage in the pre-vaccine period is essential to predict and assess the impact of PCV in settings where disease surveillance is particularly difficult. Therefore, we present data on pneumococcal carriage before the introduction of the 10-valent-pneumococcal conjugate vaccine (PCV10) in Brazil. We conducted a prospective study on a cohort of 203 children aged <5 years old, randomly selected in an urban community located in the periphery of the city of Salvador, Brazil and followed them from January/2008 to January/2009. Nasopharyngeal swabs were collected from each child at four times. In total, 721 swabs were collected, yielding a pneumococcal carriage prevalence of 55% (n=398). In multivariate analyses, the variables associated with carriage were having contact with three or more children <2 years old (OR, 2.00; 95% CI 1.33-2.89) and living in a house with an average of 3 residents per room (OR, 1.77; 95% CI 1.05-3.10). Also, white participants were more likely to be protected from colonization (OR, 0.52; 95% CI 0.29-0.93), and prevalence of carriage varied over time, with lower prevalence occurring from February to June (OR, 0.53; 95% CI 0.37-0.78) compared to July to January. Contact with children under 2 years of age and living in crowded housing also were associated with colonization by highly invasive serotypes, although this relationship was not significant. The most prevalent vaccine serotypes were 6A/B (25.4%), 19F (10.1%) and 14 (9.0%), while the most prevalent non-vaccine serotypes were 16F (4.8%), 15B/C (4.5%) and 6C/D (3.5%). Overall, 38.4% (153/398) of the isolates were non-susceptible to penicillin, and of those, 73.8% (113/153) were non-susceptible to trimethoprim/sulfamethoxazole. Colonization rate by PCV10 serotypes was 52.2%. Routine PCV10 vaccination can lead to significant changes in pneumococcal serotypes found in NP colonization, indicating a need for continued monitoring, especially in crowded settings, as occurs in Brazil's slums.

Temporal trends and clonal diversity of penicillin non-susceptible pneumococci from meningitis cases from 1996 to 2012, in Salvador, Brazil.

BACKGROUND: Hospital-based surveillance for pneumococcal meningitis has been conducted since January 1996 in the city of Salvador, Brazil. The purpose of this study was to describe the temporal evolution of Penicillin Non-Susceptible Streptococcus pneumoniae (PNSSP) in regards to serotype distributions and clonal diversity recovered from meningitis cases over 17 years. METHODS: Broth microdilution was used to identify pneumococcal isolates that were PNSSP (Minimum Inhibitory Concentration > 0.12 µg/ml). The annual incidence rate of meningitis cases was calculated. Serotyping was defined using multiplex polymerase chain reaction assays and quellung reaction. Genetic diversity of PNSSP isolates was assessed using both pulsed-field gel electrophoresis (PFGE) and Multilocus Sequence Typing (MLST) analyses. RESULTS: A total of 854 cerebrospinal fluid (CSF) culture pneumococcal isolates were tested by broth microdilution method and serotyped. A total of 173 (20.3%) were penicillin non-susceptible (PNSSP) (Minimum Inhibitory concentration ≥ 0.12 µg/ml). The annual incidence of meningitis cases declined from 1.65/100,000 population (1996) to 0.2/100,000 population in 2012 and the rate due to PNSSP declined 82% over the 17-years of surveillance. PNSSP isolates were restricted to 13 serotypes, being the most common ones serotypes 14 (45.1%; 78/173), 23 F (19.1%; 33/173), 6B (14.4%; 25/173), 19 F (9.2%; 16/173) and 19A (5.2%; 9/173). Among the PNSSP isolates, 94% had serotypes represented in the 10-valent conjugate vaccine (PCV10). The predominant serotype 14 clonal groups were identified as PFGE group A/multilocus sequence type 66 (ST66) [35.3% (61/173)] and PFGE group GK/ST156 [4.6% (8/173)], the latter one associated with high level resistance to penicillin and ceftriaxone. CONCLUSIONS: Our results show sustained reductions in pneumococcal meningitis cases in the Metropolitan region of Salvador from 1996 to 2012. This might reflect a beneficial impact of conjugate vaccines. Continued surveillance and further studies need to be conducted to better understanding on PCV10 vaccine impact.

Case report: Co-infection of Rickettsia rickettsii and Streptococcus pyogenes: is fatal Rocky Mountain spotted fever underdiagnosed?

Rocky Mountain spotted fever, a tick-borne disease caused by Rickettsia rickettsii, is challenging to diagnose and rapidly fatal if not treated. We describe a decedent who was co-infected with group A ß-hemolytic streptococcus and R. rickettsii. Fatal cases of Rocky Mountain spotted fever may be underreported because they present as difficult to diagnose co-infections.

Serotype and genotype distributions of pneumococcal carriage isolates recovered from Brazilian children attending day-care centres.

Pneumococcal nasopharyngeal carriage isolates recovered from Brazilian children attending day-care centres in 2005 were assessed for serotype, genotype and penicillin susceptibility phenotype. As 124 of the 253 isolates (49 %) were characterized previously with respect to serotype and penicillin susceptibility, the primary objectives were to examine clonal associations and penicillin susceptibility within major serotypes and to assess the suitability of conventional multiplex PCR for deducing carriage serotypes within this population. Using a combination of PCR-based serotyping and the Quellung reaction, serotypes were identified for 81 % (205/253) of the isolates, with serogroups or types 14, 6, 23F, 19F and 18 being predominant. Included within the 205 isolates successfully serotyped by PCR were 28 isolates that had become non-viable. Forty-eight isolates were non-typable using both the PCR method and the Quellung reaction. Penicillin non-susceptibility was observed within 16 of the 18 multilocus sequence types detected. Thus, this study provides further evidence from a diverse collection of pneumococcal clones that PCR-based serotype deduction is useful for providing supportive evidence for pneumococcal conjugate vaccine implementation.

Reevaluation of the taxonomic status of recently described species of Enterococcus: evidence that E. thailandicus is a senior subjective synonym of "E. sanguinicola" and confirmation of E. caccae as a species distinct from E. silesiacus.

Several of the more recently proposed new species of Enterococcus are nearly identical based on 16S rRNA gene sequence analysis and phenotypic traits. In the present study, DNA-DNA reassociation experiments, in conjunction with sequencing of the 16S rRNA and rpoB genes, provided evidence that "Enterococcus sanguinicola" and Enterococcus thailandicus actually represent the same species. In contrast, Enterococcus caccae and Enterococcus silesiacus, two other species with nearly identical 16S rRNA gene sequences, were confirmed to be separate species.

Detection of bacterial pathogens in Mongolia meningitis surveillance with a new real-time PCR assay to detect Haemophilus influenzae.

Since the implementation of Haemophilus influenzae (Hi) serotype b vaccine, other serotypes and non-typeable strains have taken on greater importance as a cause of Hi diseases. A rapid and accurate method is needed to detect all Hi regardless of the encapsulation status. We developed 2 real-time PCR (rt-PCR) assays to detect specific regions of the protein D gene (hpd). Both hpd assays are very specific and sensitive for detection of Hi. Of the 63 non-Hi isolates representing 21 bacterial species, none was detected by the hpd #1 assay, and only one of 2 H. aphrophilus isolates was detected by the hpd #3 assay. The hpd #1 and #3 assays detected 97% (229/237) and 99% (234/237) of Hi isolates, respectively, and were superior for detection of both typeable and non-typeable Hi isolates, as compared to previously developed rt-PCR targeting ompP2 or bexA. The diagnostic sensitivity and specificity of these rt-PCR assays were assessed on cerebrospinal fluid specimens collected as part of meningitis surveillance in Ulaanbaatar, Mongolia. The etiology (Neisseria meningitidis, Hi, and Streptococcus pneumoniae) of 111 suspected meningitis cases was determined by conventional methods (culture and latex agglutination), previously developed rt-PCR assays, and the new hpd assays. The rt-PCR assays were more sensitive for detection of meningitis pathogens than other classical methods and improved detection from 50% (56/111) to 75% (83/111). The hpd #3 assay identified a non-b Hi that was missed by the bexA assay and other methods. A sensitive rt-PCR assay to detect both typeable and non-typeable Hi is a useful tool for improving Hi disease surveillance especially after Hib vaccine introduction.

Serotype distribution and antimicrobial resistance of Streptococcus pneumoniae prior to introduction of the 10-valent pneumococcal conjugate vaccine in Brazil, 2000-2007.

This study describes the serotype distribution and antibiotic resistance patterns among 397 S. pneumoniae meningitis case isolates recovered in Salvador, Brazil, during the period of 2000-2007, before introduction of the 10-valent pneumococcal conjugate vaccine. The active hospital-based surveillance showed a decline in the annual incidence rates of pneumococcal meningitis during the period of study, from 1.12 cases to 0.83 cases/100,000 persons for all age groups (P<0.001), with an overall case-fatality rate of 28.6% (113 of 395) for all patients and 41.9% (57 of 136) for those <5 years of age. Serotypes 14 (n=55; 13.9%), 3 (n=32; 8.1%), 23F (n=32; 8.1%), 19F (n=31; 7.8%), 6B (n=30; 7.6%), 18C (n=28; 7.1%), and 6A (n=20; 5%) were the most prevalent serotypes. In patients <5 years the estimated projected coverage of 7-, 10- and 13-valent conjugate vaccines was 74.3%, 75.7% and 83.1%, respectively. Antimicrobial susceptibility testing revealed that 22.1% (n=88) of isolates were non-susceptible to penicillin, 56% were non-susceptible to trimethoprim/sulphamethoxazole, and 29.6% were non-susceptible to tetracycline. Nonsusceptibility to penicillin and cefotaxime was detected solely among serotype 14 isolates (n=4; 1%). This study provides an important baseline to assess the impact of conjugate vaccine implantation on the epidemiology of meningitis due to Streptococcus pneumoniae in Salvador, Brazil.

Prevalence of Streptococcus pneumoniae serotype 6C among invasive and carriage isolates in metropolitan Salvador, Brazil, from 1996 to 2007.

The newly described Streptococcus pneumoniae serotype 6C accounted for 2.3% (16/709) of meningitis cases and 3.2% (3/95) of nasopharyngeal isolates from healthy individuals in Brazil. The strains were multidrug resistant (18.8%) and genetically diverse. Despite low serotype 6C prevalence, continuous surveillance is necessary to guide vaccine strategies.

Designation of the provisional new enterococcus species CDC PNS-E2 as Enterococcus sanguinicola sp. nov., isolated from human blood, and identification of a strain previously named Enterococcus CDC PNS-E1 as Enterococcus italicus Fortina, Ricci, Mora, and Manachini 2004.

We have previously characterized two new enterococcal species (provisionally designated CDC PNS-E1 and CDC PNS-E2) recovered from clinically significant specimens associated with invasive infections in humans. In the present report we provide additional data and propose formal denominations for isolates of these two species of Enterococcus. Results of 16S rRNA gene sequencing, sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of whole-cell protein profiles, and DNA-DNA reassociation experiments indicated that the blood isolate ATCC BAA-780 (SS 1728; CDC PNS-E1) corresponds to Enterococcus italicus, whose species epithet was proposed to designate isolates from artisanal Italian cheese. Strain ATCC BAA-781 (CCUG 47861; SS 1729; CDC PNS-E2), a vancomycin-resistant isolate recovered from the blood of a patient in the United States, was found to be highly related at the species level to another blood isolate (SS 1743; CCUG 47884) from Sweden, and for these we propose the designation Enterococcus sanguinicola sp. nov.