Salmonella Panama: genetic diversity of the isolates collected from human and non-human sources

Abstract INTRODUCTION Salmonella enterica serovar Panama belongs to the D1 serogroup and is frequently associated with nontyphoidal salmonellosis in humans. This study aimed to characterize isolates collected from Northeast Brazil by phenotypic and molecular methods. METHODS Forty four S. Panama strains were examined for antimicrobial susceptibility, virulence genes, and pulsed field gel electrophoresis (PFGE) types. RESULTS All strains were susceptible to antibiotics (except for streptomycin), presented classical virulence factors, and could be clustered into four groups and 18 pulsotypes. CONCLUSIONS This work calls for continuous surveillance for the emergence of antibiotic resistance and new clones in a geographical area.

Meningitis caused by Salmonella enterica serotype Panama in Brazil: first case reported

Abstract Salmonella infections usually occur as gastroenteritis that is generally self-limited. However, some serotypes of Salmonella can cause severe extra-intestinal infections, such as bacteremia and meningitis. Here, we report the first Salmonella Panama case of meningitis in 4-month-old male newborn in Brazil. The invasive strain isolated was susceptible to all antimicrobial agents tested. The genes agfA, fimA, invA, sfbA, phoP, and slyA were detected using polymerase chain reactions. These findings are relevant and physicians should be alert to the possibility of meningitis in newborns due to S. Panama, which can present a high rate of mortality or recurrence of infection.

Antimicrobial resistance in Neisseria gonorrhoeae: history, molecular mechanisms and epidemiological aspects of an emerging global threat

ABSTRACT Neisseria gonorrhoeae is the agent of gonorrhea, a sexually transmitted infection with an estimate from The World Health Organization of 78 million new cases in people aged 15-49 worldwide during 2012. If left untreated, complications may include pelvic inflammatory disease and infertility. Antimicrobial treatment is usually effective; however, resistance has emerged successively through various molecular mechanisms for all the regularly used therapeutic agents throughout decades. Detection of antimicrobial susceptibility is currently the most critical aspect for N. gonorrhoeae surveillance, however poorly structured health systems pose difficulties. In this review, we compiled data from worldwide reports regarding epidemiology and antimicrobial resistance in N. gonorrhoeae, and highlight the relevance of the implementation of surveillance networks to establish policies for gonorrhea treatment.

Cellular characterisation of Candida tropicalis presenting fluconazole-related trailing growth

We assessed fluconazole susceptibility in 52 Candida tropicalis clinical strains using seven antifungal susceptibility methods, including broth microdilution (BMD) [standard M27 A3 (with neutral and acid pH), ATB Fungus 3, Vitek 2 system and flow cytometric analysis] and agar-based methods (disk diffusion and E-test). Trailing growth, detection of cell-associated secreted aspartic proteases (Saps) and morphological and ultrastructural traits of these clinical strains were also examined. The ranges of fluconazole 24 h-minimum inhibitory concentration (MIC) values were similar among all methods. The essential agreement among the methods used for MIC determinations was excellent and all methods categorised all strains as susceptible, except for one strain that showed a minor error. The presence of the trailing effect was assessed by six methods. Trailing positivity was observed for 86.5-100 percent of the strains. The exception was the BMD-Ac method where trailing growth was not observed. Morphological and ultrastructural alterations were detected in C. tropicalis trailing cells, including mitochondrial swelling and cell walls with irregular shapes. We tested the production of Saps in 13 C. tropicalis strains expressing trailing growth through flow cytometry. Our results showed that all of the C. tropicalis strains up-regulated surface Sap expression after 24 h or 48 h of exposure to fluconazole, which was not observed in untreated yeast strains. We concluded that C. tropicalis strains expressing trailing growth presented some particular features on both biological and ultrastructural levels.

The genetic diversity and phenotypic characterisation of Streptococcus agalactiae isolates from Rio de Janeiro, Brazil

Streptococcus agalactiae isolates are more common among pregnant women, neonates and nonpregnant adults with underlying diseases compared to other demographic groups. In this study, we evaluate the genetic and phenotypic diversity in S. agalactiae strains from Rio de Janeiro (RJ) that were isolated from asymptomatic carriers. We analysed these S. agalactiae strains using pulsed-field gel electrophoresis (PFGE), serotyping and antimicrobial susceptibility testing, as well as by determining the macrolide resistance phenotype, and detecting the presence of the ermA/B, mefA/E and lnuB genes. The serotypes Ia, II, III and V were the most prevalent serotypes observed. The 60 strains analysed were susceptible to penicillin, vancomycin and levofloxacin. Resistance to clindamycin, chloramphenicol, erythromycin, rifampin and tetracycline was observed. Among the erythromycin and/or clindamycin resistant strains, the ermA, ermB and mefA/E genes were detected and the constitutive macrolides, lincosamides and streptogramin B-type resistance was the most prevalent phenotype observed. The lnuB gene was not detected in any of the strains studied. We found 56 PFGE electrophoretic profiles and only 22 of them were allocated in polymorphism patterns. This work presents data on the genetic diversity and prevalent capsular serotypes among RJ isolates. Approximately 85 percent of these strains came from pregnant women; therefore, these data may be helpful in developing future prophylaxis and treatment strategies for neonatal syndromes in RJ.

Phenotypical characteristics of group B streptococcus in parturients

Colonization by Group B Streptococcus (GBS) is highly prevalent among pregnant women, with prevalence rates ranging between 4 percent and 30 percent. The infection may be transmitted vertically and may result in serious neonatal consequences. In the period from November 2003 to May 2004, a cross-sectional study was carried out among 316 parturients at the Jundiaí Teaching Hospital to establish the prevalence of genital GBS colonization, to identify the factors associated with colonization and the characteristic phenotypes of these streptococci. Samples from rectal and vaginal areas were collected for selective culture in Todd-Hewitt broth. Susceptibility to 7 antimicrobial agents was tested using the antibiotic diffusion disk technique, and the isolated strains were classified using specific antisera. The prevalence of GBS colonization was 14.6 percent. No strain was resistant to penicillin, ampicillin, erythromycin or nitrofurantoin. The majority of strains were sensitive to cephalothin. Greatest resistance was to gentamicin (76.1 percent), followed by clindamycin (17.4 percent). The most frequent serotype was Ib (23.9 percent), followed by serotypes II and Ia (19.6 percent and 17.4 percent, respectively). There was no correlation between serotype and greater antimicrobial resistance. In conclusion, the prevalence of GBS in parturients was high and penicillin continues to be the drug of choice for intrapartum prophylaxis. The most frequent serotype (Ib) found in this study differs from those found in the majority of studies carried out in other countries, revealing the need to identify prevalent serotypes in each region so that specific vaccines can be designed.

Sensibilidade de Streptococcus agalactiae aos agentes antimicrobianos / Susceptibility of Streptococcus agalactiae to antimicrobial agents

A sensibilidade de Streptococcus agalactiae frente a 13 antimicrobianos foi verificada pelo teste da difusäo em ágar. As amostras testadas foram sensíveis a ampicilina, cefalotina, cefoxitina, clindamicina, cloranfenicol, eritromicina, lincomicina, penicilina, rifampicina e vancomicina, apresentando sensibilidade variável para a tetra ciclina e resistência a canamicina e tobramicina. Foram também determinadas, para as estirpes, as concentraçöes mínimas inibitórias (CMIs) pelo teste da diluiçäo em ágar para 6 antimicrobianos. Para a ampicilina, cefalotina, clindamicina, lincomicina e penicilina, as CMI50 e CMI90 apresentaram valores similares aos encontrados para a CMI. Para a eritromicina, a CMI90 (0,12 microng/ml) foi duas vezes maior que a CMI50

Isolamento de estreptococos do grupo B, de gestantes e neonatos, em Florianópolis, Santa Catarina / Isolation of group B streptococci in parturient and newborn, in Florianópolis (SC)

O ocorrência de estreptococos do grupo B de Lancefield foi estudada em 135 parturientes na Maternidade Carmela Dutra em Florianópolis (SC) e em seus respectivos neonatos. Os materiais clínicos foram coletados da vagina das mulheres, do ouvido dos neonatos e do ânus de ambas as populaçöes. As taxas de isolamento do microorganismo foram de 25,2% entre as mäes, 11,9% entre as crianças e de 18,5% entre as duas populaçöes. Foram isoladas 75 amostras, sendo que ocorreu um predomínio dos tipos sorológicos II/Ic e III. Em 14 binômios foi isolado o mesmo tipo sorológico na mäe e no neonato correspondente

Susceptibilidade de Estreptococos do grupo B isolados no período perinatal aos antimicrobianos / Antimicrobial susceptibility of groups B Streptococcus isolated in the perinatal period

A susceptibilidade de 107 amostras de estreptococos do grupo B a 10 antibióticos foi avaliada "in vitro" pela técnica de difusäo do antibiótico a partir de discos e pela determinaçäo da concentraçäo mínima inibitória através do método de diluiçäo em agar. Todas as amostras foram sensíveis às penicilinas, cefalotina, lincomicina e cefoxitina, e resistentes a dois aminoglicosídeos. Somente 7,5% dos microrganismos foram sensíveis à tetraciclina e menos de 2% foram resistentes ao cloranfenicol e eritromicina. Entre os antibióticos aos quais pelo menos 90% das amostras foram sensíveis, as concentraçöes inibitórias variaram de 0,06 microng/ml para a penicilina a 8 microng/ml para o cloranfenicol. Já para os aminoglicosídeos e a tetraciclina esses valores foram >- 32 microng/ml