Four hundred ninety-nine methicillin-resistant Staphylococcus aureus (MRSA) isolates recovered from 1996 to 1998 from 22 hospitals in five countries of Latin America-Argentina, Brazil, Chile, Uruguay ...and Mexico-were examined for antimicrobial susceptibility and clonal type in order to define the endemic clones in those hospitals. The hybridization of ClaI restriction digests with the mecA- and Tn554-specific DNA probes combined with pulsed-field gel electrophoresis of chromosomal SmaI digests (ClaI-mecA::ClaI-Tn554::PFGE clonal types) documented not only the predominance and persistence of the Brazilian clone (XI::B::B) in Brazil (97%) and Argentina (86%) but also its massive dissemination to Uruguay (100%). Moreover, a close relative of the Brazilian clone (XI::kappa::B) was highly represented in Chile (53%) together with a novel clone (47%) (II::E'::F) resistant to pencillin, oxacillin, ciprofloxacin, chloramphenicol, clindamycin, erythromycin, and gentamicin. A unique clonal type (I::NH::M) was detected in Mexico among pediatric isolates and was resistant to penicillin, oxacillin, and gentamicin only. This study clearly documented the very large capacity for geographic expansion and the persistence of the Brazilian clone, contributing not only to the increasing uniformity of the MRSA in South America but worldwide as well.
Highlights ► Laboratory-based surveillance demonstrated the impact of vaccination against Hib. ► Detected changes in serotype distribution of Haemophilus influenzae meningitis. ► Continued ...characterization of invasive H. influenzae isolates in Brazil is needed.
Summary Objectives We have recently found a high prevalence of non-typeable pneumococcal isolates (NTPn) circulating in day-care centers in Central Brazil, besides serotype 14 isolates. We therefore ...examined the genetic relationship among NTPn and serotype 14 from carriage and invasive pneumococcal isolates obtained from children attending emergency rooms enrolled in a population-based surveillance. Methods The isolates were characterized by Quellung reaction serotyping, PCR for the presence of pneumolysin and the loci for a capsule gene ( cpsA ) and the type 14 gene ( cps14H ) in all NTPn, and by multilocus sequence typing and pulsed field gel electrophoresis. Results 87.2% of the isolates were clustered into nine clusters. The major cluster included 41 pneumococcal serotype 14 (28 carriage and 13 invasive isolates) and two NTPn related to the global pneumococcal clone Spain9V -3. Overall, 95.4% of the NTPn carriage strains were genetically related to carriage or invasive strains expressing serotype 14. A dominant NTPn lineage was found, that grouped 14 pneumococcal strains. Almost half of the multidrug-resistant isolates grouped into the NTPn cluster. Conclusion These findings provide baseline data to assess the impact of the pneumococcal vaccination on the molecular epidemiology of Streptococcus pneumoniae . Changes in frequency of NTPn isolates and also genetic changes should be carefully monitored post vaccination, to detect potential vaccine-escape or replacement disease by capsule switched strains, especially in areas where colonization with NTPn has been frequently observed.
To determine whether serotypes of S. pneumoniae isolated from the nasopharynx (NP) are representative of data from patients with invasive disease, we collected NP swab specimens from children, ...between 3 months and 5 years and obtained data from 105 children hospitalized with invasive disease. The prevalence of penicillin nonsusceptible strains in the NP carriage and invasive disease group was 16.4% and 17%, respectively, in the first period and 42% and 45% in the second period. The serotypes 23F, 6A, 14 and 19F were the most common in the NP study and 14, 1, 5 and 6B were the most common in invasive infections.
To analyze the profile of antimicrobial susceptibility of meningococcal disease isolates collected throughout Brazil from 2006 to 2008 and forwarded to the National Reference Laboratory for ...Meningitis, Institute Adolfo Lutz - São Paulo.
The MIC to penicillin, ampicillin, chloramphenicol, ceftriaxone, ciprofloxacin and rifampicin was determined in a sample of 1096 (55% of the total isolates received) randomly chosen using the broth microdilution procedure. The breakpoints used were those recommended by the European Monitoring Group on Meningococci (EMGM).
Decreased susceptibility to penicillin and ampicillin was detected in 13% and 12.9% respectively. All isolates were susceptible to chloramphenicol, ceftriaxone, and ciprofloxacin. Two strains (0.2%) showed high resistance to rifampicin and 0.5% of the isolates displayed intermediate resistance to rifampicin.
The meningococcal strains isolated in Brazil during 2006-2008 were globally susceptible to all antibiotics currently used in treatment or chemoprophylaxis of meningococcal disease in Brazil.
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