Factors associated with increased risk in inappropriate empiric antibiotic treatment of childhood bacteraemia.

UNLABELLED: To identify bacteraemic children who are at increased risk of inappropriate empiric antibiotic therapy, we performed univariate and multivariate analyses of prospectively-studied bacteraemic episodes. Appropriateness of therapy was defined according to the in vitro susceptibility of the isolate. Inappropriate empiric therapy was found in 38% of 516 bacteraemic episodes and was associated with higher mortality. The rate of inappropriate treatment was lower in neonates and infants (28% and 33%, respectively) but higher in children 1- to 5-years old (51%, P = 0.0029). The rate was dependent on the source of bacteraemia (range, 18%-70%, P = 0.0092), underlying conditions (range, 26%-53%, P = 0.0001), the specific paediatric section in which the child was hospitalized (range, 24%-70%, P = 0.0002), and the causative micro-organism (range, 15%-75%, P < 0.0001). Four clinical variables that independently and significantly affected the rate of inappropriate antibiotic treatment were identified by multivariate stepwise logistic regression analysis (odds ratios in parentheses): hospital-acquired bacteraemia (2.3), age of 1- to 5-years (2.1), cytotoxic therapy (1.8) and presence of central i.v. line (1.6). CONCLUSION: We defined bacteraemic children who are at risk of inappropriate empiric antibiotic therapy. Special efforts are needed to improve their treatment and consequently their outcome.

Postcircumcision urinary tract infection.

The possible association of urinary tract infection (UTI) with ritual circumcision on the eighth day of life was studied by analyzing the epidemiology of urinary tract infections during the first year of life in 169 children with UTI (56 males and 113 females) born in Israel from 1979 to 1984. Forty-eight percent of the episodes of UTI occurring in males appeared during the 12 days following circumcision, and the increased incidence during that period was highly significant. The median age of the males at the time of the UTI was 16 days, compared with seven months in females. Ritual Jewish circumcision as practiced in Israel may be a predisposing factor for UTI during the 12-day period following that procedure.

Bacterial adherence to intravenous catheters and needles and its influence by cannula type and bacterial surface hydrophobicity.

Bacterial adherence to intravenous (IV) catheters and needles (cannulas) was studied morphologically by scanning electron microscopy and determined quantitatively with radiolabeled bacteria. Electron micrographs showed that bacteria adhered well to IV cannulas with formation of microcolonies. The adherence process was studied quantitatively, as related to cannula composition and bacterial surface hydrophobicity. The adherence of the bacteria examined (per square centimeter) was lowest to siliconized steel needles, higher to Teflon catheters, and highest to polyethylene catheters. The results for Staphylococcus aureus were (9.9 +/- 0.9) X 10(5) bacteria/cm2 adhered to steel needles, (37.2 +/- 2.8) X 10(5) bacteria/cm2 to Teflon catheters, and (168.4 +/- 15.6) X 10(5) bacteria/cm2 to polyethylene catheters. Hydrophobic bacteria (S. aureus and Serratia marcescens), as determined by their adherence to liquid hydrocarbons, adhered better than less hydrophobic species (Escherichia coli). The role of hydrophobicity was documented by showing that hydrophobic S. marcescens adhered to IV catheters 18- to 27-fold better than its less hydrophobic mutants. It is concluded that IV steel needles have an advantage over plastic cannulas regarding bacterial adherence in vitro, and inasmuch as infectious complications in vivo were indeed shown to be lower with IV needles, their usage should be preferred.

Cell-mediated immune response to bacterial products in human tonsils and peripheral blood lymphocytes.

Lymphoproliferative responses of tonsillar tissue lymphocytes and peripheral blood lymphocytes to phytohemagglutinin and specific bacterial product antigens were studied in children undergoing tonsillectomy and adenoidectomy. Tonsillar tissue lymphocytes responded to optimal concentrations of phytohemagglutinin. Varidase, and streptolysin-O in a manner similar to peripheral blood lymphocytes. Higher base-line mitogenic activity in tonsillar lymphocytes was frequently associated with the presence of Staphylococcus aureus in the tonsils. Tonsillar tissue lymphocytes from 23% of the subjects with the highest base-line mitogenic activity manifested a decreased response to in vitro stimulation with mitogens or antigens. In subjects with such preactivated tonsillar lymphocytes, the proliferative responsiveness of blood lymphocytes to mitogen and antigens was markedly increased after tonsillectomy and adenoidectomy. These observations suggest the existence of in vitro correlates of cellular immunity to bacterial products in the mucosal surfaces. In addition, it is proposed that tonsils may possess immunosuppressive activity for peripheral blood lymphocytes, which may be related to local tonsillar infections.

The effect of attapulgite and charcoal on enterotoxicity of Vibrio cholerae and Escherichia coli enterotoxins in rabbits.

Vibrio cholerae and certain strains of Escherichia coli produce heat-labile enterotoxins which play a significant role in the pathogenesis of the intestinal disease. Activated attapulgite, a heated magnesium aluminum silicate, was previously shown to prevent the toxic effects of endotoxin. The present study has revealed that this drug inhibits the toxic effects of cholera and E. coli enterotoxins in the intestinal loop of rabbits, when toxin and attapulgite are pre-incubated prior to injection. Up to 50 to 100 minimal effective doses are inhibited. Attapulgite is effective also when injected separately, albeit simultaneously, into the intestinal loops, but not when administered after the toxin. Since supernates of toxinattapulgite mixtures are non-toxic, it is postulated that attapulgite acts by adsorption and that the attached enterotoxin is no longer toxic to the rabbit intestine. The previously reported effect of charcoal on V. cholerae enterotoxin paralleling that of attapulgite, was confirmed. In contrast to the effects of these absorbents on isolated toxin, both failed to prevent enterotoxicity in the rabbit model of an enterotoxin-producing strain of E. coli.

Avulsion of the posterior cruciate ligament from its femoral attachment: an isolated ligamentous injury.

A unique previously unreported injury is described, namely the avulsion of the posterior cruciate ligament from its femoral attachment, as an isolated injury. The mechanism of injury, i.e., hyperextension, is also unique although it is one that is commonly experienced by riders attempting to start their motorcycles.