Genomic features of mecA-positive methicillin-resistant Mammaliicoccus sciuri causing fatal infections in pets admitted to a veterinary intensive care unit.

Methicillin-resistant staphylococci have become leading cause of infectious diseases in humans and animals, being categorized as high priority pathogens by the World Health Organization. Although methicillin-resistant Staphylococcus sciuri (recently moved to Mammaliicoccus sciuri) has been widely reported in companion animals, there is scarce information regarding their clinical impact and genomic features. Herein, we reported the occurrence and genomic characteristics of methicillin-resistant M. sciuri recovered from fatal infections in pets admitted to an intensive care unit of a veterinary hospital, in Brazil. Two M. sciuri strains were isolated from bronchoalveolar lavage samples collected from dog (strain SS01) and cat (strain SS02) presenting with sepsis and acute respiratory distress syndrome. Both isolates displayed a multidrug-resistant profile, whereas whole-genome sequencing analysis confirmed the presence of the mecA gene, along to genetic determinant conferring resistance to macrolides, streptogramins, aminoglycosides, and trimethoprim. For both strains, the mec and crr gene complex shared high identity (≥97%) with analogue sequences from a M. sciuri isolated from a human wound infection, in the Czech Republic. Strains were assigned to the sequence type ST52 and the novel ST74. Phylogenomic analysis revealed a broad host range association of these strains with several hosts and sources, including humans, animals, food, and the environment through different years and geographic locations. Our findings demonstrate that infections caused by mecA-positive M. sciuri strains can be a serious threat for veterinary intensive care patients and the medical staff, with additional implications for One Health approaches.

Long-term effect of 10-valent pneumococcal conjugate vaccine on nasopharyngeal carriage of Streptococcus pneumoniae in children in Brazil.

Brazil introduced the 10-valent pneumococcal vaccine (PCV10) to the routine national immunization program (NIP) in March 2010. In 2017, we investigated the effects of PCV10 on nasopharyngeal carriage of vaccine-types (VT) and non-vaccine-types (NVT) of Streptococcus pneumoniae (Spn) among children living in São Paulo city. We also compared the prevalence of VT and NVT with previous carriage surveys performed in 2010 (baseline) and 2013. METHOD: The carriage survey was conducted among 531 children, aged 12 months to <24 months, recruited from public Primary Health Units during the immunization campaign, using previous surveys methodology, except for qPCR, which was performed in the 2017 survey only. RESULTS: No statistical difference was found in the prevalence of Spn either by culture (59.7%) or by qPCR (61.2%). Spn carriage increased from 40.3% (baseline) to 59.7% (2017 survey) (p < 0.001). Colonization by VT isolates significantly decreased by 90.9% (19.8-1.8%) and 95.5% (19.8-0.9%) in the 2013 and 2017 surveys, respectively, compared to that at baseline. NVT isolates increased significantly by 128% (19.6-44.8%) and 185% (19.6-55.9%) in the respective post-PCV10 surveys, most led to high prevalence of serotypes 6C (27%), 15B (9.8%), 19A (9.2%), 15A (6.0%), and 16F (5.7%). In 2017, reduction in serotype 6A (4.2-0.6%, p < 0.001) and increase in serotype 19A (1.8-6.0%, p = 0.001) were found; serotype 3 isolate was not detected in the present survey. We identified the emergence of 19A isolates CC320, associated with high penicillin (MIC ≥ 2.0 mg/L) and cefotaxime (MIC ≥ 1.0 mg/L) values. CONCLUSION: After 7 years of PCV10 introduction in the NIP, colonization by VT among toddlers decreased substantially to a residual level, along with substantial serotype replacement by novel serotypes not present in any current conjugated pneumococcal vaccine and serotype 19A. The present findings can assist policy decisions in Brazil.

VanA-type vancomycin-resistant Enterococcus faecium ST1336 isolated from mussels in an anthropogenically impacted ecosystem.

We report the occurrence and genomic features of multidrug-resistant vancomycin-resistant Enterococcus faecium vanA belonging to a novel sequence type (designated ST1336), carrying a Tn1546-like element, in marine brown mussels (Perna perna) from anthropogenically affected coastal waters of the Atlantic coast of Brazil, highlighting a potential source of dissemination for related ecosystems, with additional consequences for seafood safety and quality.

Changed epidemiology during intra and interhospital spread of high-risk clones of vanA-containing Enterococcus in Brazilian hospitals.

We report changes in the molecular epidemiology of vanA-containing Enterococcus during the intra and interhospital spread of high-risk clones, in Southeastern Brazil. While VRE faecalis predominated during 1998 to 2006, a reversal has been observed in the last years, where VRE faecium belonging to ST114, ST203, ST412, ST478 and ST858 have become endemic.

Effect of 10-valent pneumococcal conjugate vaccine on nasopharyngeal carriage of Streptococcus pneumoniae and Haemophilus influenzae among children in São Paulo, Brazil.

In March 2010, Brazil introduced the 10-valent pneumococcal conjugate vaccine (PCV10) in the routine infant immunization program using a 4-dose schedule and catch-up for children <23months. We investigated PCV10 effect on nasopharyngeal carriage with vaccine-type Streptococcus pneumoniae (Spn) and non-typeable Haemophilus influenzae (NTHi) among children in São Paulo city. Cross-sectional surveys were conducted in 2010 (baseline) and 2013 (post-PCV10). Healthy PCV-naïve children aged 12-23months were recruited from primary health centers during immunization campaigns. Nasopharyngeal swabs were collected and tested for Hi; for Spn, all baseline and a stratified random sample of 400 post-PCV10 swabs were tested. We compared vaccine-type Spn and NTHi carriage prevalence pre-/post-PCV10, and used logistic regression to estimate PCV10 effectiveness (1-adjusted odds ratio×100%). Overall 501 children were included in the baseline and 1167 in the post-PCV10 survey (including 400 tested for Spn). Spn was detected in 40.3% of children at baseline and 48.8% post-PCV10; PCV10 serotypes were found in 19.8% and 1.8% respectively, representing a decline of 90.9% (p<0.0001). Carriage of vaccine-related serotypes increased (10.8-21.0%, p<0.0001), driven primarily by a rise in serotype 6C (1.8-11.2%, p<0.0001); carriage of serotypes 6A and 19A did not significantly change. PCV10 effectiveness (4 doses) against vaccine-type carriage was 97.3% (95% confidence interval 88.7-99.3). NTHi prevalence increased from 26.0% (130/501) to 43.6% (509/1167, p<0.0001); PCV10 vaccination seemed significantly associated with NTHi carriage, even after adjusting for other known risk factors. Carriage with PCV10 serotypes among toddlers declined dramatically following PCV10 introduction in São Paulo, Brazil. No protection of PCV10 against NTHi was observed. Our findings contribute to a growing body of evidence of PCV10 impact on vaccine-type carriage and highlight the importance of PCV10 as a tool to reduce the burden of pneumococcal disease in Brazil and globally.

Changes in serotype distribution of Haemophilus influenzae meningitis isolates identified through laboratory-based surveillance following routine childhood vaccination against H. influenzae type b in Brazil.

Following routine childhood vaccination against Haemophilus influenzae type b (Hib) disease in Brazil in 1999, passive laboratory surveillance reported increasing numbers of non-b serotypes and nontypeable H. influenzae (NTHi) from meningitis cases. To characterize this increase, we analyzed data on 3910 H. influenzae isolated from cerebrospinal fluid or blood from meningitis cases that were sent to the national reference laboratory for serotyping from 1990 to 2008. Hib accounted for 98% of H. influenzae meningitis isolates received during 1990-1999 versus 59% during 2000-2008, while non-b serotypes increased from 1% to 19% and NTHi increased from 2% to 22% of H. influenzae isolates received during the two periods. Higher proportions of non-b serotypes and NTHi than Hib were isolated from blood rather than cerebrospinal fluid. Estimated incidence rates for H. influenzae meningitis for Sao Paulo state remained below 1 case per million population during 2000-2008, although annual incidence of NTHi meningitis (mean, 0.03 cases per 100,000 population) increased in several age groups. Changes in surveillance for H. influenzae following introduction of Hib conjugate vaccine likely contributed to increased numbers of non-b and nontypeable H. influenzae meningitis isolates received at the national reference laboratory.

Outbreak of vancomycin-resistant enterococci in a tertiary hospital: the lack of effect of measures directed mainly by surveillance cultures and differences in response between Enterococcus faecium and Enterococcus faecalis.

To describe the effect of active surveillance to control vancomycin-resistant enterococci (VRE) after an outbreak, 549 surveillance rectal cultures were performed in 308 patients (35% positive). An educational intervention to prevent transmission was implemented. Infection and colonization by VR- Enterococcus faecalis decreased, but Enterococcus faecium persisted despite control measures. Infections by VR-E faecalis fell to zero in 2008. We observed difficulties in controlling colonization with measures directed mainly by surveillance cultures and differences between responses of E faecium and E faecalis.

Multilocus sequence typing of hospital-associated Enterococcus faecium from Brazil reveals their unique evolutionary history.

We studied the genetic relationships between vancomycin-susceptible (n = 11) and -resistant Enterococcus faecium (VRE, n = 20) recovered from Brazil using a multilocus sequence typing (MLST) scheme. Grouping of allelic profiles revealed six clusters of related sequence types (STs) that differ in no more than two of the seven alleles. Of these, one cluster harbored 16 of the 20 isolates recovered during the first VRE outbreak in Brazil. The ampicillin and gentamicin resistance profiles were stable in the isolates that clustered within the groups I-III. Comparison with the allelic profiles of 139 E. faecium from different geographical regions and origins found in the international database http://www.mlst.net revealed that the Brazilian outbreak clone did not cluster in the previously named complex-17. This genetic complex contains hospital epidemic and clinical isolates recovered from different countries and continents. Twenty two of the 31 Brazilian isolates, including the VRE outbreak clone, clustered apart from the E. faecium isolates from the database, suggesting that these Brazilian isolates have a distinct evolutionary history.

Evaluation of clonality in enterococci isolated in Brazil carrying Tn1546-like elements associated with vanA plasmids.

Fifty-one vancomycin-resistant enterococci samples isolated from different geographic regions in Brazil were studied. All the isolates harboured the vanA gene as demonstrated by PCR analysis, and in a majority of strains the gene was associated with a transferable plasmid of 70 kb. A single variant of the prototype Tn1546 associated with common transferable vanA-containing plasmids has spread among the enterococcal strains circulating in Brazil. The VanA element integrity in these enterococci strains and the different pulsed-field gel electrophoresis patterns suggest horizontal transmission of the vancomycin resistance transposon in Brazilian strains.

Occurrence of insertion sequences within the genomes and Tn1546-like elements of glycopeptide-resistant enterococci isolated in Brazil, and identification of a novel element, ISEfa5.

Insertion sequences (IS) occur widely within the Tn1546-like elements responsible for VanA glycopeptide resistance in enterococci from several countries. As such insertions can be used as epidemiological markers and for studying horizontal transfer of gene clusters, we investigated the distribution of IS6770, IS1542, IS1216V, IS1476, and IS1251 elements in 26 VanA Enterococcus faecium and 21 VanA Enterococcus faecalis from Brazil. PCR, using genomic DNA as a template, indicated that most of the isolates contained IS6770 (97%), IS1216V (87%) and IS1476 (72%) elements. IS1251 was also detected, but at a higher frequency in E. faecium (80%) than in E. faecalis (14%). None of the isolates harboured IS1542. Only two of 47 isolates had IS elements within their Tn1546-like elements; one possessed IS1251 between vanS and vanH, as reported in the United States; another possessed a novel IS element, designated ISEfa5, located between vanX and van Y. This novel element was found in the genomic DNA of 25 (96%) E. faecium and II (52%) E. faecalis. In stability studies, no IS-mediated changes were detected in the Tn1546-like elements of 25 vancomycin-resistant enterococci (VRE) monitored over 11 months. These results suggest that the occurrence of IS in Brazilian isolates is similar to that reported in American isolates, but that these elements occur rarely within the vanA gene clusters. As patterns of IS carriage did not correlate with the PFGE type of the VRE, the prevalence of IS elements in genomic DNA of VRE is not a useful epidemiological marker. However, the presence of IS-modified Tn1546-like elements, which appear to be rare in Brazil, could be a useful molecular marker in local epidemiological studies to monitor the evolution and horizontal transmission of VanA elements.

Oropharyngeal colonization by Haemophilus influenzae in healthy children from Taubaté (São Paulo), prior to the Haemophilus influenzae type B vaccination program in Brazil.

UNLABELLED: Haemophilus influenzae is one of the most important bacterial agents of otitis and sinusitis. H. influenzae type b (Hib) is one of the main causes of meningitis, pneumonia, and septicemia in nonvaccinated children under 6 years of age. The aims of this study were to determine the prevalence of H. influenzae and Hib oropharyngeal colonization prior to the onset of the Hib vaccination program in Brazil in previously healthy children and to assess the susceptibility profile of this microorganism to a selected group of antimicrobials that are used to treat acute respiratory infections. METHOD: Cultures of Haemophilus influenzae were made from oropharynx swabs from 987 children under 6 years of age who were enrolled in 29 day-care centers in Taubaté (a city of São Paulo state, Brazil) between July and December 1998. RESULTS: The prevalence of H. influenzae carriers was 17.4%, and only 5.5% of the strains were beta-lactamase producers. The prevalence of Hib carriers was high, 7.3% on average (range, 0.0 - 33.3%). CONCLUSIONS: The low prevalence of colonization by penicillin-resistant strains indicates that it is not necessary to substitute ampicilin or amoxicilin to effectively treat otitis and sinusitis caused by H. influenzae in Taubaté.

Multilocus variable-number tandem-repeat polymorphism among Brazilian Enterococcus faecalis strains.

Multilocus variable-number tandem-repeat analysis (MLVA) for seven genomic loci was developed for Enterococcus faecalis. MLVA and pulsed-field gel electrophoresis (PFGE) resulted in 37 and 31 genotypes among 83 strains, respectively. Both typing schemes were highly concordant (90.4%). MLVA is an excellent alternative to PFGE.

Oropharyngeal colonization by Haemophilus influenzae in healthy children from Taubaté (São Paulo), prior to the Haemophilus influenzae type b vaccination program in Brazil

Haemophilus influenzae é um dos mais importantes agentes bacterianos de otites e sinusites. Em crianças menores de seis anos de idade não vacinadas contra o H. influenzae do tipo b (Hib), essa bactéria é uma das principais causadoras de meningite, pneumonia e sepse. O objetivo deste estudo foi determinar a prevalência da colonização da orofaringe de crianças previamente saudáveis por H. influenzae e Hib e avaliar o perfil de suscetibilidade desses microorganismos a um grupo seleto de antimicrobianos, que habitualmente são utilizados para tratar as infecções respiratórias agudas. MÉTODO: Foram colhidos swabs da orofaringe de 987 crianças menores de seis anos de idade que freqüentavam 29 creches da cidade de Taubaté (São Paulo, Brasil), entre julho e dezembro de 1998, para realização de culturas de H. influenzae e antibiograma. RESULTADOS: A prevalência de portadores do H. influenzae foi de 17,4% e somente 5,5% das cepas isoladas eram produtoras de beta-lactamase. A prevalência de portadores do Hib foi alta, com média de 7,3% (variando entre 0.0 e 33,3%). CONCLUSÕES: A baixa prevalência da colonização por cepas resistentes às penicilinas indica que não é necessário substituir esses antibióticos para tratar empiricamente as otites e sinusites causadas por H. influenzae em Taubaté.

Typing of pneumococcal surface protein A (PspA) in Streptococcus pneumoniae isolated during epidemiological surveillance in Brazil: towards novel pneumococcal protein vaccines.

Pneumococcal protein vaccine based on pneumococcal surface protein A (PspA) is in development with the potential to offer broad range of protection against different strains. We have investigated the frequency of PspA family 1 (Fam1) and family 2 (Fam2) proteins among Streptococcus pneumoniae recovered from ongoing surveillance in Brazil. Fam1 and Fam2 were expressed in comparable rates among 366 isolates, with the potential coverage of 94.3%. PspA families were not associated to age group or source of isolates. However, considering the significant tendency of increasing prevalence of Fam2 associated to widespread dissemination of the genetically-related resistant strains, the monitoring of the PspA families derived from population-based data may be necessary in the context of vaccine development.

Evaluation of methodology for serotyping invasive and nasopharyngeal isolates of Haemophilus influenzae in the ongoing surveillance in Brazil.

To assess the magnitude of discrepant results obtained by routine Haemophilus influenzae serotyping, 258 isolates, collected by the epidemiological surveillance system in Brazil from individuals with invasive diseases or carriage, were evaluated by two slide agglutination (SlAg) methods: SlAg method 1, by which strains were initially screened with a serotype b-specific antiserum, and SlAg method 2, by which strains were tested against all serotype-specific antisera in parallel. Investigators comparing results of the two SlAg methods with those obtained by capsule type-specific PCR were blinded to the method used. The serotype prevalence rates found by the three methods were significantly different, involving discrepancies mainly between serotype b and noncapsulated (NC) isolates. For invasive isolates (n = 131), the overall agreement rate between SlAg method 1 or 2 and PCR was 68.0 or 88.3%, respectively, whereas for colonizing isolates (n = 127) the corresponding rate was 46.5 or 94.2%, respectively. SlAg method 2 improved the ascertainment of serotypes over that obtained with SlAg method 1, demonstrating good correlation with PCR. Use of the polyvalent antiserum as a screening reagent for SlAg for invasive and colonizing isolates showed poor discriminatory power, with a sensitivity of 65.8% and a specificity of 91.7%. We stress the importance of using a well-standardized SlAg methodology and suggest that reference laboratories should utilize PCR routinely to confirm SlAg results and to check all nonspecific SlAg reactions and apparent NC isolates by SlAg in order to provide reliable data on the prevalence of H. influenzae serotypes in the H. influenzae type b vaccine era.

Phenotypic and genotypic characterization of VanA Enterococcus isolated during the first nosocomial outbreak in Brazil.

We report the phenotypic and genotypic characterization of 50 VanA Enterococcus clinical isolates from infected patients and 97 isolates from colonized patients obtained during a nosocomial outbreak in a single hospital in São Paulo, Brazil during 1998. The identification of strains to the species level by conventional biochemical and phenotypic tests and by multiplex PCR assay had 100% agreement. Both E. faecalis and E. faecium were isolated from patients during this outbreak. The vanA genotype was confirmed by PCR. Antibiotic susceptibility testing showed that E. faecium isolates are generally less susceptible to antibiotics than E. faecalis. By PCR, 24 of 26 VRE strains tested carried the Tn1546 element. Pulsed-field gel electrophoresis identified five distinct patterns for E. faecalis (A, B, C, D, E) and three for E. faecium (M, N, and O). A single PFGE pattern was identified in the majority of strains of each species and does not discriminate between case and carrier isolates.

Characterization of haemophilus influenzae isolated from invasive disease in Brazil from 1990 to 1999.

The Haemophilus influenzae serotype b (Hib) conjugate vaccine was introduced in the National Immunization Program in Brazil in the second half of 1999. A retrospective analysis on serotypes, biotypes, and antimicrobial resistance of Hi invasive strains obtained through Hi survey was conducted to document the characteristics of this pathogenic agent during a decade prior the use of Hib vaccine. A total 3,204 strains from 1990 to 1999 were studied, being 88.2% isolated from cerebrospinal fluid, 10.7% from blood, and 1.1% from pleural fluid. The rate of 90.9% of strains was obtained from children up to 4 years old, and the age group >6 months old to 1 year was the higher risk to Hi infection. Type b was, by far, the most common type (97.8%), followed in frequency by type a (0.5%); only 1.5% was a nontypable strain. Biotypes I and II accounted for 97.8% of isolates. Resistance to ampicillin (AM) and chloramphenicol (CO) was detected at rates of 18.1% and 19.1%, respectively, whereas simultaneous resistance to AM and CO was identified in 13.9% of strains. Total concordance was found between AM resistance and beta-lactamase production. No strain showed resistance to ceftriaxone and rifampicin. In conclusion, the data generated through this laboratory-based surveillance should serve as a reference for assessing the impact of Hib vaccination and to detect changes on the pattern of Hi diseases in the country.