RESUMO
Pneumocystis jirovecii is a leading cause of opportunistic infections among immunocompromised patients. The aim of this study was to determine the genetic diversity of P. jirovecii from colonized Cuban infants and toddlers by analysis of four genetic loci: mitochondrial large subunit (mtLSU) rRNA, cytochrome b (CYB), superoxide dismutase (SOD) and ß-tubulin (ß-tub). We determined the multilocus profiles based on concatenated genotype data (multilocus genotype; MLG) and nucleotide sequences (multilocus sequence analysis; MLSA) respectively, calculated the discriminatory power of each analysis, and investigated possible associations with demographic and clinical data. Sixteen of 51 PCR-positive nasopharyngeal swab specimens (years 2010-2013) with high P. jirovecii load were selected for downstream analysis. In mixed allelic profiles all genotypes/nucleotide sequence patterns were considered separately. All samples could be genotyped based on mtLSU, CYB and ß-tub locus. However, the SOD locus could be successfully amplified in only 7/16 (44%) specimens. Eight different P. jirovecii MLGs were identified among the 16 cases and eight samples presented identical MLG (MLG 1). Seventeen MLSA profiles were distinguished. No statistical association between genotypes or MLGs and demographic or clinical data could be identified. For MLSA the higher discriminatory power (S=0.976) was observed. The combination of mtLSU, CYB and ß-tub loci proved to be useful for molecular epidemiology studies of P. jirovecii. A total of 17 different MLSA profiles observed in 16 specimens indicated high genetic variability of P. jirovecii circulating in colonized Cuban infants and toddlers.
Assuntos
Pneumocystis carinii/genética , Pneumonia por Pneumocystis/microbiologia , Cuba/epidemiologia , DNA Fúngico/análise , DNA Fúngico/genética , Feminino , Variação Genética , Genótipo , Humanos , Lactente , Masculino , Pneumocystis carinii/classificação , Pneumocystis carinii/isolamento & purificação , Pneumonia por Pneumocystis/epidemiologiaRESUMO
This study describes the prevalence and genotype distribution of Pneumocystis jirovecii obtained from nasopharyngeal (NP) swabs from immunocompetent Cuban infants and toddlers with whooping cough (WC). A total of 163 NP swabs from 163 young Cuban children with WC who were admitted to the respiratory care units at two pediatric centers were studied. The prevalence of the organism was determined by a quantitative PCR (qPCR) assay targeting the P. jirovecii mitochondrial large subunit (mtLSU) rRNA gene. Genotypes were identified by direct sequencing of mtLSU ribosomal DNA (rDNA) and restriction fragment length polymorphism (RFLP) analysis of the dihydropteroate synthase (DHPS) gene amplicons. qPCR detected P. jirovecii DNA in 48/163 (29.4%) samples. mtLSU rDNA sequence analysis revealed the presence of three different genotypes in the population. Genotype 2 was most common (48%), followed in prevalence by genotypes 1 (23%) and 3 (19%); mixed-genotype infections were seen in 10% of the cases. RFLP analysis of DHPS PCR products revealed four genotypes, 18% of which were associated with resistance to sulfa drugs. Only contact with coughers (prevalence ratio [PR], 3.51 [95% confidence interval {CI}, 1.79 to 6.87]; P = 0.000) and exposure to tobacco smoke (PR, 1.82 [95% CI, 1.14 to 2.92]; P = 0.009) were statistically associated with being colonized by P. jirovecii. The prevalence of P. jirovecii in infants and toddlers with WC and the genotyping results provide evidence that this population represents a potential reservoir and transmission source of P. jirovecii.
Assuntos
Infecções por Pneumocystis/epidemiologia , Infecções por Pneumocystis/microbiologia , Pneumocystis carinii/classificação , Pneumocystis carinii/isolamento & purificação , Coqueluche/complicações , Criança , Pré-Escolar , Cuba/epidemiologia , DNA Fúngico/química , DNA Fúngico/genética , Feminino , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Dados de Sequência Molecular , Nasofaringe/microbiologia , Pneumocystis carinii/genética , Polimorfismo de Fragmento de Restrição , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA , Coqueluche/microbiologiaRESUMO
Since 1989, we have been involved in the development of a vaccine against Haemophilus influenzae type b. The new vaccine is based on the conjugation of synthetic oligosaccharides to tetanus toxoid. Our main goals have been (i) to verify the feasibility of using the synthetic antigen and (ii) to search for new production alternatives for this important infant vaccine. Overall, eight trials have already been conducted with adults, children (4 to 5 years old), and infants. We have described herein the details from the first two phase I clinical trials conducted with human adult volunteers under double blind, randomized conditions. The participants each received a single intramuscular injection to evaluate safety and initial immunogenicity. We have found an excellent safety profile and an antibody response similar to the one observed for the control vaccine.
Assuntos
Infecções por Haemophilus/prevenção & controle , Vacinas Anti-Haemophilus/administração & dosagem , Haemophilus influenzae tipo b/imunologia , Adulto , Anticorpos Antibacterianos/sangue , Especificidade de Anticorpos , Método Duplo-Cego , Ensaio de Imunoadsorção Enzimática , Infecções por Haemophilus/imunologia , Vacinas Anti-Haemophilus/efeitos adversos , Vacinas Anti-Haemophilus/imunologia , Humanos , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Masculino , Estudos Retrospectivos , Teste Bactericida do Soro , Vacinas ConjugadasRESUMO
The prevalence of nasopharyngeal carriage of Moraxella catarrhalis was determined for the first time in Cuba. One-hundred fifty healthy children attending three day-care centers in the municipality of Marianao, Havana City were studied. The percentage of recovering bacteria in nasal and pharyngeal swabs was compared. Antimicrobial susceptibilities to ampicillin, trimethoprim-sulfamethoxazole, tetracycline, cefotaxime, ceftriaxone, chloramphenicol, erythromycin, azithromycin, amoxicillin/clavulanate, and norfloxacin were determined by the disk diffusion method according to recommendations of the National Committee for Clinical Laboratory Standards. Sixty-five percent of the children studied carried Moraxella catarrhalis. The nasal cavity was the main isolation site for this organism (81% of positive cultures). Most strains were highly susceptible to the antimicrobial agents tested, except to ampicillin (53.6% resistance). This study provides evidence of the need for continued surveillance of antimicrobial susceptibility of Moraxella catarrhali, in order to determine optimal empiric therapy for community-acquired respiratory tract infections produced by this pathogen.