RESUMO
Colorimetric determinations of proteolytic activity were performed to measure the effects on dye protean substrates including tissue powders. The substrates were assayed with 98 strains obtained from the milk of cows with mastitis. Trypsin was employed as positive control and it verified the susceptibility of the method. Enzymatic activity was estimated in trypsin units per milliliter of incubation mixture. The percentages of strains active on specific proteins were 47.8% for elastin, 61.6% for collagen and when hide powder and udder extract were used as dye substrates, the proteolytic staphylococci were 76.5 and 92.4% respectively. There was no significant difference in hydrolytic activity on proteins between coagulase positive and coagulase negative cocci.
Assuntos
Colágeno/metabolismo , Elastina/metabolismo , Endopeptidases/análise , Metaloendopeptidases/análise , Staphylococcus/enzimologia , Animais , Bovinos , Colorimetria , Endopeptidases/metabolismo , Feminino , Glândulas Mamárias Animais/metabolismo , Metaloendopeptidases/metabolismo , Leite/microbiologia , Padrões de Referência , Pele/metabolismo , Staphylococcus/crescimento & desenvolvimento , TripsinaRESUMO
Thirty six Klebsiella pneumoniae strains were assayed in a test to determine bacterial interference; two of them had bacteriocinic effects on homologous species, strains 6 and 150 inhibited sensitive K. pneumoniae and they also acted on positive and negative Staphylococci coagulase. All cocci were sensitive to the bacteriocinogenic K. pneumoniae and none of the non-bacteriocinogenic strains inhibited them. Klebocin with homologous activity on K. pneumoniae seemed to be undistinguishable from the compound with heterologous action on Staphylococci in the aspects that were characterized in this work; both were heat labile to the same degree; optimum pH was 7, acidity decreased klebocin activity more intensely than alkaline pH. The antagonistic substance was not produced in the synthetic medium employed and was developed in tryptic soy, nutrient agar, brain heart agar and blood agar; tryptone-beef extract agar complex medium neither permitted the homologous activity nor allowed the interference on Staphylococci. The compound (or compounds) responsible for homologous antimicrobial effect had a low molecular weight as demonstrated by the fact that it pierces a dialysis membrane with molecular weight of 10,000 D cut-offs. Ethidium bromide treatment of strains 6 and 150 produced five strains without bacteriocinic activity which simultaneously lost their homologous and heterologous inhibitory capacity.
Assuntos
Bacteriocinas/farmacologia , Klebsiella pneumoniae/metabolismo , Staphylococcus/efeitos dos fármacos , Bacteriocinas/biossíntese , Meios de Cultura , Microbiologia de Alimentos , Humanos , Concentração de Íons de Hidrogênio , Klebsiella pneumoniae/crescimento & desenvolvimento , Peso Molecular , Intoxicação Alimentar Estafilocócica/microbiologia , Staphylococcus/crescimento & desenvolvimento , TemperaturaRESUMO
At the Pediatric Intensive Care Unit of the Provincial Regional Hospital, in Río Cuarto, Argentina, nearly all hospitalized infants showed clinical symptoms of septicaemia and gastroenteritis. Neither Salmonella nor Shigella were found in the stool cultures, but Klebsiella pneumoniae was isolated as predominant flora. Three haemocultures displayed K. pneumoniae and Enterobacter cloacae; the other three developed only E. cloacae. Since the infants came from different places and it was possible to isolate members of the Klebsielleae tribe from all of them, a hospital infection was suspected. Searching for the infectious source, K. pneumoniae was detected in the water bath used to keep the feeding-bottles at 37 degrees C. To clarify the existence of any relationship between the strains isolated from patients and from the water bath, several characteristics were compared: biotypes, haemolityc activity, antibiotic sensibility patterns, and pathogenicity, assessed as lethal dose 50%. Identical results were found for the biochemical tests of all the strains belonging to the same species. The antibiotic sensibility patterns and LD 50% showed quite similar values. All bacteria displayed haemolityc activity for rabbit and lamb erythrocytes. It could be considered that the septicaemia had an intestinal origin, and that the infection spread was due to the contamination of the water bath where the feeding bottles were kept.
Assuntos
Infecção Hospitalar/epidemiologia , Surtos de Doenças/epidemiologia , Unidades de Terapia Intensiva , Infecções por Klebsiella/epidemiologia , Antibacterianos/farmacologia , Argentina , Resistência Microbiana a Medicamentos , Enterobacter/isolamento & purificação , Fezes/microbiologia , Humanos , Lactente , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/isolamento & purificaçãoRESUMO
At the Pediatric Intensive Care Unit of the Provincial Regional Hospital, in Río Cuarto, Argentina, nearly all hospitalized infants showed clinical symptoms of septicaemia and gastroenteritis. Neither Salmonella nor Shigella were found in the stool cultures, but Klebsiella pneumoniae was isolated as predominant flora. Three haemocultures displayed K. pneumoniae and Enterobacter cloacae; the other three developed only E. cloacae. Since the infants came from different places and it was possible to isolate members of the Klebsielleae tribe from all of them, a hospital infection was suspected. Searching for the infectious source, K. pneumoniae was detected in the water bath used to keep the feeding-bottles at 37 degrees C. To clarify the existence of any relationship between the strains isolated from patients and from the water bath, several characteristics were compared: biotypes, haemolityc activity, antibiotic sensibility patterns, and pathogenicity, assessed as lethal dose 50
. Identical results were found for the biochemical tests of all the strains belonging to the same species. The antibiotic sensibility patterns and LD 50
showed quite similar values. All bacteria displayed haemolityc activity for rabbit and lamb erythrocytes. It could be considered that the septicaemia had an intestinal origin, and that the infection spread was due to the contamination of the water bath where the feeding bottles were kept.
RESUMO
At the Pediatric Intensive Care Unit of the Provincial Regional Hospital, in Río Cuarto, Argentina, nearly all hospitalized infants showed clinical symptoms of septicaemia and gastroenteritis. Neither Salmonella nor Shigella were found in the stool cultures, but Klebsiella pneumoniae was isolated as predominant flora. Three haemocultures displayed K. pneumoniae and Enterobacter cloacae; the other three developed only E. cloacae. Since the infants came from different places and it was possible to isolate members of the Klebsielleae tribe from all of them, a hospital infection was suspected. Searching for the infectious source, K. pneumoniae was detected in the water bath used to keep the feeding-bottles at 37 degrees C. To clarify the existence of any relationship between the strains isolated from patients and from the water bath, several characteristics were compared: biotypes, haemolityc activity, antibiotic sensibility patterns, and pathogenicity, assessed as lethal dose 50
. Identical results were found for the biochemical tests of all the strains belonging to the same species. The antibiotic sensibility patterns and LD 50
showed quite similar values. All bacteria displayed haemolityc activity for rabbit and lamb erythrocytes. It could be considered that the septicaemia had an intestinal origin, and that the infection spread was due to the contamination of the water bath where the feeding bottles were kept.