Bacteriocin-like activity of Bacteroides fragilis group isolated from marmosets.

The ability of strains of the B. fragilis group, isolated from the oral cavity and intestine of marmosets, to produce bacteriorin-like substances in solid medium, in terms of auto-, iso- and heteroantagonism, was evaluated. Antagonistic activity was exhibited by 52% of the intestinal strains, 3 of which showed autoantagonistic activity. Three out of 9 oral strains isolated, tested against themselves, showed simultaneous isoantagonism to 4 indicator strains; but not autoantagonism. The same 9 oral strains, when tested against 16 reference strains, revealed interspecific activity only against 2 Gram-positive microorganisms. Higher activity, evaluated by the size of the inhibition halo, was observed in BHI-S agar, and greatest inhibition was obtained after 72 h of incubation.

Extraction, partial purification and characterization of a bacteriocin (fragicilin) produced by a strain of Bacteroides fragilis isolated from Callithrix penicillata.

A strain of Bacteroides fragilis, isolated from the marmoset Callithrix penicillata, produced protein(s) with bacteriocin activity (fragicilin). Two active fractions (36 and 150 kDa) were isolated by chromatography. The bacteriocin exhibited iso- and heteroantagonism. It remained stable between pH 3 and 10 and at 60 degrees C for 24 h. Pronase, trypsin, proteinase K and type VII protease inactivated the bacteriocin, giving evidence of its protein nature.

Antimicrobial resistance and plasmid detection in strains of the Bacteroides fragilis group.

Resistant populations of the Bacteroides fragilis group bacteria (two reference ones and two isolated from human and Callithrix penicillata marmoset) were obtained by the gradient plate technique, to clindamycin, penicillin G, metronidazole and mercuric chloride. All the four tested strains were originally susceptible to the four antimicrobial drugs at the breakpoint used in this study. MICs determination for the four cultures gave constant values for each antimicrobial, on the several steps by the gradient plate technique. The intestinal human B. fragilis strains showed three DNA bands, that could be representative of only two plasmids in the closed covalently circular (CCC) form with molecular weights of approximately 25 and 2.5 Md. The results do not permit an association between the presence of plasmid in the human strain with the susceptibility to the studied drugs. The four strains were beta-lactamase negative in the two methods used, and no particular chromosomal genetic resistance marker was demonstrated. The resistance (MIC) observed, after contact with penicillin G and mercuric chloride, were two-fold in the four tested strains.

Isolation and identification of strains of Bacteroides fragilis group from the digestive tract of Callithrix penicillata marmosets.

Thirty-five strains of the Bacteroides fragilis group were isolated from oral and intestinal samples from 5 wild caught, captive Callithrix penicillata. Nine oral strains of Bacteroides fragilis (7) and Bacteroides distasonis (2), and 26 intestinal strains of Bacteroides fragilis (14) and Bacteroides distasonis (12) were identified.

Bacteriological evaluation of wounds in seriously burned hospitalized patients.

During the period between May and December 1988, 21 patients were studied bacteriologically at Hospital João XXIII's burn's unit which belongs to "Fundação Hospitalar do Estado de Minas Gerais" in Belo Horizonte, Brazil. A qualitative and quantitative evaluation of aerobic and facultative bacteria from burn wounds was carried out by the standard filter paper disc technique, including antibiotic susceptibility. At the same time an evaluation of those bacteria isolated from the environmental unit was performed. The most common organisms recovered from wounds of patients were: Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. P. pseudomallei was the most frequent strain recovered from environmental specimens. In nearly all patients specimens (16 in total) from whom P. aeruginosa was isolated, the rate of CFU/cm2 of skin was above 10(2). In nine of these, it reached 10(5), which is equivalent to 10(7) CFU/g of burned tissue.

Susceptibility of Actinobacillus actinomycetemcomitans strains to norfloxacin.

The minimal inhibitory concentration of norfloxacin to Actinobacillus actinomycetemcomitans strains isolated from patients with localized juvenile periodontitis was determined by using an agar dilution method. All the tested strains, including the three reference strains, were susceptible at concentrations lower than the breakpoint used, with 90% of the strains susceptible to 0.125 micrograms/ml.

Infection by Trypanosoma vivax in goats and sheep in the Brazilian semiarid region: from acute disease outbreak to chronic cryptic infection.

A study was undertaken to investigate the role of Trypanosoma vivax in sheep and goat mortality and abortions in the Brazilian semiarid region, where outbreaks had been previously reported in bovines. For this purpose, 177 goats and 248 sheep (20% of herds) were randomly sampled on four farms in the State of Paraiba in May and October 2008. The animals were screened for trypanosomes by the buffy coat technique (BCT) and PCR. Infected animals, approximately 25% in both surveys, manifested apathy, pale mucous membranes, enlarged lymph nodes, weakness, weight loss, opacity of the cornea, blindness and abortion. However, the animals with acute and severe disease showing the highest levels of parasitemia and fever, which many times resulted in death, were only detected in the first survey. These severely diseased animals exhibited progressive weight loss and had the smallest packed cell volume (PCV) values. During survey 2, done in October 2008 on the same farms, only animals with low parasitemia and normal temperatures, PCV values and body weights were detected. Therefore, animals that spontaneously recovered from acute infection developed chronic and asymptomatic disease. This finding demonstrated for the first time that sheep and goats, which are the most important livestock in the semiarid region of Brazil, may be severely injured by T. vivax infection and also play a role as asymptomatic carriers and important sources of T. vivax to ruminants in general.

Avaliação da atividade cicatrizante do jucá (Caesalpinia ferrea Mart. ex Tul. var. ferrea) em lesões cutâneas de caprinos / Evaluation of the Brazilian ironwood (Caesalpinia ferrea Mart. ex Tul. var. ferrea) healing activity on cutaneous lesions of goats

O objetivo deste estudo foi demonstrar os efeitos do tratamento tópico do jucá (Caesalpinia ferrea) em feridas cutâneas. Quinze caprinos machos sem raça definida foram divididos em 3 grupos de acordo com o pós-cirúrgico (7º, 14º e 21º dias). As feridas experimentais foram tratadas com a pomada composta pela casca da Caesalpinia ferrea em pó misturada com a vaselina estéril e as do grupo controle apenas com a vaselina esterilizada. A aplicação diária da pomada e da vaselina estéril foi realizada sobre ferida circular padronizada de 16 cm² de área na região torácica de cada animal. As avaliações das feridas foram feitas do ponto de vista clínico, bacteriológico, morfométrico e histopatológico nos períodos pré-determinados (7º, 14º e 21º dias). Morfometricamente, as feridas do controle apresentaram áreas cirúrgicas menores e grau de contração maior que as do grupo tratado, entretanto, histologicamente, houve completa epitelização das feridas tratadas no 21º dia, enquanto que as feridas do grupo controle necessitavam de mais tempo para resolução do processo cicatricial. No exame microbiológico realizado no momento da produção da ferida, não se observou crescimento bacteriano e no momento das biópsias, identificou-se a presença de bactérias da família Enterobacteriaceae e Staphylococcus aureus, sendo que a partir do 14º dia observou-se Staphylococcus aureus apenas no grupo controle. A utilização tópica da pomada de Caesalpinia ferrea apresentou eficiência significativa no auxílio da reparação cicatricial de feridas cutâneas de caprinos.

The aim of this study was to demonstrate the effects of the topical treatment with Brazilian ironwood (Caesalpinia ferrea) on cutaneous wounds. Fifteen male mongrel goats were divided into 3 groups according to the postoperative period ((7th, 14th and 21st days). The experimental wounds were treated with an ointment composed of Brazilian wood powder bark mixed with sterile vaseline, whereas controls were only treated with sterile Vaseline. The ointment and the sterile vaselin were daily applied on a standardized circular wound (16 cm² area) in the thoracic region of each animal. Clinical, bacteriological, morphometric and histopathological evaluations were performed in the wounds at predetermined periods (7th, 14th and 21st postoperative days). Morphometrically, control wounds had smaller surgical areas and greater degree of contraction than those from the treated group. However, histologically, there was a complete epithelialization of the treated wounds on the 21st day, whereas control wounds required longer time for healing. In the microbiological evaluation performed at the moment of wound production, there was no bacterial growth. During biopsies, Enterobacteriaceae bacteria and Staphylococcus aureus were identified; from the 14th day, the latter was only observed in the control group. The topical use of Caesalpinia ferrea ointment was significantly efficient to help healing cutaneous wounds in goats.

[Infection control procedures used in dental offices in Belo Horizonte]. / Procedimentos utilizados no controle de infecção em consultórios odontológicos de Belo Horizonte.

Survey data from 300 randomly selected private dental practitioners working in Belo Horizonte, Minas Gerais, were used to evaluate the infection control procedures routinely practiced here. The function of this report might be to alert the teaching team from Dental Schools and the dentists to the problems that potentially contribute to the transmission of infectious disease as a first step for additional specific recommendations to an effective and safe infection controL program that we intend to discuss later.

Purification and partial characterization of a bacteriocin isolated from Bacteroides ovatus H47.

A new intracellular bacteriocin isolated from a human fecal strain of Bacteroides ovatus was partially purified through ammonium sulfate precipitation, ion exchange chromatography, gel filtration, and preparative polyacrylamide gel electrophoresis (PAGE). The bacteriocin is stable at a pH range of 3-10, at 60 degrees C for 24 h, and at -70 degrees C for 6 months. It is inactivated by proteolytic enzymes. The molecular weight, estimated by sodium dodecyl sulfate--PAGE, is 78 kDa. Fifty strains of the Bacteroides fragilis group were isolated from fecal samples, and 41 of the isolates were shown to produce an antagonistic substance against at least 1 indicator strain. Iso-, auto-, and hetero-antagonisms were observed.

In vitro activity of two beta-lactam antibiotics against strains of the Bacteroides fragilis group isolated from humans and from Callithrix penicillata marmosets.

The purpose of this study was to determine the in vitro activity of cefoxitin and imipenem against strains of the Bacteroides fragilis group isolated from the intestinal tract of humans and Callithrix penicillata marmosets. The majority of the human and marmosets B. fragilis strains was resistant to cefoxitin. The percentages of resistance to cefoxitin among B. fragilis marmoset strains were higher than those of human origin. On the other hand, the majority of the other Bacteroides of the B. fragilis group isolated from human and marmosets were susceptible to this drug. Imipenem was the most effective beta-lactam drug in this study, and we detected no resistance.