Rebeca Inhoque Pereira

Molecular detection of virulence factors among food and clinical Enterococcus faecalis strains in South Brazil

The present report aimed to perform a molecular epidemiological survey by investigating the presence of virulence factors in E. faecalis isolated from different human clinical (n = 57) and food samples (n = 55) in Porto Alegre, Brazil, collected from 2006 to 2009. In addition, the ability to form biofilm in vitro on polystyrene and the β-haemolytic and gelatinase activities were determined. Clinical strains presented a higher prevalence of aggregation substance (agg), enterococcal surface protein (esp) and cytolysin (cylA) genes when compared with food isolates. The esp gene was found only in clinical strains. On the other hand, the gelatinase (gelE) and adherence factor (ace) genes had similar prevalence among the strains, showing the widespread occurrence of these virulence factors among food and clinical E. faecalis strains in South Brazil. More than three virulence factor genes were detected in 77.2% and 18.2% of clinical and food strains, respectively. Gelatinase and β-haemolysin activities were not associated with the presence of gelE and cylA genes. The ability to produce biofilm was detected in 100% of clinical and 94.6% of food isolates, and clinical strains were more able to form biofilm than the food isolates (Student’s t-test, p < 0.01). Results from the statistical analysis showed significant associations between strong biofilm formation and ace (p = 0.015) and gelE (p = 0.007) genes in clinical strains. In conclusion, our data indicate that E. faecalis strains isolated from clinical and food samples possess distinctive patterns of virulence factors, with a larger number of genes that encode virulence factors detected in clinical strains.

Resistance to antimicrobial agents among enterococci isolated from fecal samples of wild marine species in the southern coast of Brazil

The purpose of this study was to evaluate species distribution, antimicrobial resistance profiles, and presence of resistance genes in enterococci isolated from fecal samples of wild marine species, including seabirds (n=12), sea turtles (n=8), and mammals (n=3) found alive or dead in southern coast of Brazil. Enterococci were classified based on phenotypic and genotypic characteristics, tested for antibiotic susceptibility, and the presence of tet(S), tet(M), tet(L), mrsC, and erm(B) genes by PCR. Enterococcus faecalis and Enterococcus faecium were the most common species. Single (37.09%), double (25.80%), and multiple (16.12%) antibiotic resistance patterns were observed. Resistance to rifampicin occurred most frequently. The msrC, tet(M), and/or tet(L) genes were detected in 60.15%, 73.07%, and 23.07% of the resistant strains, respectively. In conclusion, the presence of antibiotic resistant strains in these species could be related to food web interactions and aquatic pollutants or linked to environmental resistome.

PCR-RFLP of 16S ribosomal DNA to confirm the identification of Enterococcus gallinarum and Enterococcus casseliflavus isolated from clinical and food samples

INTRODUCTION This study aimed to confirm the identification of Enterococcus gallinarum and Enterococcus casseliflavus isolated from clinical and food samples by PCR-RFLP. METHODS Fifty-two strains identified by conventional biochemical exams were submitted to PCR amplification and digested with HinfI. Only 20 (38.5%) of the 52 strains showed a DNA pattern expected for E. gallinarum and E. casseliflavus. RESULTS Analysis of the results of this study showed that E. gallinarum and E. casseliflavus are occasionally erroneously identified and confirmed the potential application of 16S rDNA analysis for accurate identification of these species. CONCLUSIONS A correct identification is important to distinguish between intrinsic and acquired vancomycin resistance.

Complete Genome Sequence of Enterococcus faecalis Strain P8-1 Isolated from Wild Magellanic Penguin (Spheniscus magellanicus) Feces on the South Coast of Brazil.

ABSTRACT Enterococcus faecalis strains have a ubiquitous nature that allows them to survive in different niches. Studies involving enterococci isolated from marine animals are scarce. Therefore, in this study, we report the complete genome sequence of E. faecalis strain P8-1 isolated from feces of a Magellanic penguin on the south coast of Brazil.

Antimicrobial Resistance Profiles in Enterococcus spp. Isolates From Fecal Samples of Wild and Captive Black Capuchin Monkeys (Sapajus nigritus) in South Brazil

The environment, human, and animals play an important role in the spread of antibiotic-resistant bacteria. Enterococci are members of the gastrointestinal tracts of humans and animals and represent important reservoirs of antibiotic resistance genes. Until today, few studies have examined antibiotic susceptibility in enterococci isolated from primates. Therefore, the present study investigated species distribution, antibiotic susceptibility, and resistance genes in enterococci isolated from wild and captive black capuchins monkeys (Sapajus nigritus) in Rio Grande do Sul, South Brazil. A total of 24 swabs/fecal samples were collected, including 19 from wild monkeys living in two forest fragments [São Sebastião do Caí (SSC) and Santa Cruz do Sul (SCS)], and five in captive [Parque Zoológico da Fundação Zoobotânica (ZOO)], between August 2016 and November 2017. Fifteen colonies were randomly selected from each sample. Enterococci were identified by MALDI-TOF, tested for susceptibility to 12 antibiotics; and screened for tet(S), tet(M), tet(L), msrC, and erm(B) genes by PCR. Two-hundred ninety-six enterococci were isolated (SSC n = 137; SCS n = 86; ZOO n = 73) and differences in Enterococcus species distribution were detected on three monkey groups, with low abundance in SCS (1 - D = 0.2), followed by ZOO (1 - D = 0.68), and SSC (1 - D = 0.73). The enterococci frequently recovered include the following: Enterococcus faecalis (42.6%), E. hirae (29.1%), and E. faecium (15.9%). Antibiotic-nonsusceptible was observed in 202 (67.9%) strains. The rate of non-susceptibility to rifampicin, tetracycline, erythromycin, nitrofurantoin, chloramphenicol, and ampicillin was 46%, 26%, 22% and 19%, 13%, 0.3%, and 0.3%, respectively. All strains were susceptible to vancomycin, streptomycin, gentamycin, and linezolid. Forty-three (14.52%) isolates were identified as multidrug resistant (MDR), and the highest number of MDR enterococci were E. faecium recovered from wild monkeys living close to a hospital and water treatment plant. Elevated rates of antibiotic resistance genes msrC and tet(L) were isolates from ZOO. In conclusion, differences in the frequency of enterococci species, antibiotic-nonsusceptible and antibiotic resistance genes in all groups of monkeys were identified. These data suggest that anthropogenic activities could have an impact in the resistome of primate gut enterococci communities.