Lactoferrin and lactoferricin B reduce adhesion and biofilm formation in the intestinal symbionts Bacteroides fragilis and Bacteroides thetaiotaomicron.

Several factors affect the composition of species that inhabit our intestinal tract, including mode of delivery, genetics and nutrition. Antimicrobial peptides and proteins secreted in the gastrointestinal tract are powerful tools against bacteria. Lactoferrin (LF) inhibits the growth of several bacterial species, such as Enterobacteriaceae, but may stimulate probiotic bacteria.

Novel large-scale chromosomal transfer in Bacteroides fragilis contributes to its pan-genome and rapid environmental adaptation.

Bacteroides fragilis, an important component of the human gastrointestinal microbiota, can cause lethal extra-intestinal infection upon escape from the gastrointestinal tract. We demonstrated transfer and recombination of large chromosomal segments from B. fragilis HMW615, a multidrug resistant clinical isolate, to B.

Inactivation of MarR gene homologs increases susceptibility to antimicrobials in Bacteroides fragilis.

Bacteroides fragilis is the strict anaerobic bacteria most commonly found in human infections, and has a high mortality rate. Among other virulence factors, the remarkable ability to acquire resistance to a variety of antimicrobial agents and to tolerate nanomolar concentrations of oxygen explains in part their success in causing infection and colonizing the mucosa. Much attention has been given to genes related to multiple drug resistance derived from plasmids, integrons or transposon, but such genes are also detected in chromosomal systems, like the mar (multiple antibiotic resistance) locus, that confer resistance to a range of drugs.

Differential proteomic analysis of outer membrane enriched extracts of Bacteroides fragilis grown under bile salts stress.

Bacteroides fragilis is the most commonly isolated anaerobic bacteria from infectious processes. Several virulence traits contribute to the pathogenic nature of this bacterium, including the ability to tolerate the high concentrations of bile found in the gastrointestinal tract (GIT). The activity of bile salts is similar to detergents and may lead to membrane permeabilization and cell death.

The Ellis Island Effect: A novel mobile element in a multi-drug resistant clinical isolate includes a mosaic of resistance genes from Gram-positive bacteria.

 , a Gram-negative anaerobic bacterium, is alternately a gut commensal or virulent pathogen and is an important reservoir for horizontal gene transfer (HGT) of bacterial resistance and virulence genes in the human gastrointestinal tract. We identified a unique conjugative transposon (CTn) in a multidrug resistant clinical isolate of (BF-HMW615); we named this element CTnHyb because it included a hybrid mosaic of foreign elements. This study reports the characterization of CTnHyb and discusses the potential impact on horizontal spread of resistance genes.

Clostridium difficile infection among immunocompromised patients in Rio de Janeiro, Brazil and detection of moxifloxacin resistance in a ribotype 014 strain.

Clostridium difficile is a Gram-positive spore forming anaerobic bacterium, often associated with nosocomial diarrhea and pseudomembranous colitis. The acquisition of this organism occurs primarily in hospitals through accidental ingestion of spores, and its establishment and proliferation in the colon results from the removal of members of the normal intestinal flora during or after antibiotic therapy. In this study, stool samples from patients admitted to the University Hospital Clementino Fraga Filho (HUCCF/UFRJ) were screened for C.

Detection of resistance genes and susceptibility patterns in Bacteroides and Parabacteroides strains.

Susceptibility to five antimicrobials was determined for Bacteroides spp. (n = 52) and Parabacteroides distasonis (n = 8). All isolates were susceptible to metronidazole.

Characterization of Clostridium difficile strains isolated from immunosuppressed inpatients in a hospital in Rio de Janeiro, Brazil.

The aim of this work was to identify and characterize Clostridium difficile strains from fecal and hospital environmental samples. C. difficile toxins were detected by ELISA in 28.

Enterotoxigenic and nontoxigenic Bacteroides fragilis strains isolated in Brazil.

The presence of enterotoxigenic Bacteroides fragilis and nontoxigenic B. fragilis (NTBF) among 109 strains isolated from 1980-2008 in Brazil were investigated by PCR. One strain, representing 0.

The utility of the polymerase chain reaction assay for aetiologic definition of unspecified bacterial meningitis cases.

Most patients with acute suppurative meningitis are otherwise healthy individuals with regard to immune mechanisms against invasive bacterial disease. This medical emergency is among the most dramatic and potentially ravaging diseases that affect humans, particularly young children. The illness often strikes suddenly, and can either result in death or leave the survivors with significant neurological dysfunctions.

Diagnosis of meningococcal meningitis in Brazil by use of PCR.

Fever and a petechial rash are strongly associated with meningococcal disease in the city of Rio de Janeiro. Early antibiotic therapy is indicated and, consequently, a reduction of confirmed cases by culture, Gram stain, and latex agglutination test is expected. We evaluated a multiplex PCR assay to identify Neisseria meningitidis, Streptococcus pneumoniae and Haemophilus influenzae in biological samples from cases of non-culture proven meningitis with a petechial rash at presentation.

New PCR ribotypes of Clostridium difficile detected in children in Brazil: prevalent types of Clostridium difficile in Brazil.

A total of 35 Brazilian isolates of Clostridium difficile from faecal stools and four isolates from hospital environments were analyzed by PCR ribotyping. A whole cell protein profile (as an alternative for serogrouping), in vitro toxin production and susceptibility to vancomycin, metronidazole and clindamycin were also investigated. All strains were typeable by both phenotypic and genotypic methods, and a total of 13 different PCR ribotypes were identified, of which seven (132, 133, 134, 135, 136, 142 and 143) were considered new types and accounted for 78.

Assessment of a two-step nucleic acid amplification assay for detection of Neisseria meningitidis followed by capsular genogrouping.

Immediate prevention of meningococcal disease relies in part on the prompt treatment with antibiotics of household and other close contacts of cases; however intervention with effective vaccination relies on identification of serogroup-causing strains. Parenteral antibiotic for patient with suspected meningococcal disease before hospital admission is currently recommended. Laboratory standard methods are hindered by failure to detect bacteria by this medical approach to improve patient prognosis.

Decreased susceptibility to nitroimidazoles among Bacteroides species in Brazil.

In this study, 197 strains of Bacteroides genus from different species and origins were evaluated with regard to their susceptibility to 5-nitroimidazoles (5-Ni)-such as tinidazole, ornidazole, and metronidazole-using the agar dilution method. The presence of nim genes was also investigated by polymerase chain reaction. It was found that 5.