Antibiotic use after cefuroxime prophylaxis in hip and knee joint replacement.

The amount of additional antibiotics measured by defined daily dose (DDD) methods after 2651 hip and 362 knee replacements was assessed after prophylaxis with one or three doses (1502/1511 patients) of cefuroxime. No differences were observed between the two regimens with respect to total amount, type, indication, and duration of additional antibiotics. The incidence of joint sepsis did not differ significantly between the two trial arms, but the sample was too small for definite conclusions. There were 11.4 DDD/100 bed days of additional antibiotics used in 21% of patients after hip replacement and 15.7 DDD/100 bed days in 31% after knee replacement. For wound problems, 3.8 and 6.9 DDD/100 bed days were given in the hip- and knee-replacement groups. For distant infection, 6.5 DDD/100 bed days was administered in both groups. Duration of therapy varied only in relation to indication. Prescribed were penicillins (43% to 50%), sulfonamides (18%), cephalosporins (10% to 16%), and nitrofurantoin (8% to 13%); drug use was related to the type of infection.

Nonlysozyme antibacterial factor in human tears. Fact or fiction?

The existence of nonlysozyme antibacterial activity in tear fluid was reinvestigated. Tear fluid was fractionated by ultrafiltration and affinity chromatography. The antibacterial activity, detected in native tear fluid, coincided with the presence of lysozyme in the fractions. No antibacterial activity could be detected by agar diffusion in the fractions that should contain the low molecular mass antibacterial factors of tear fluid, reported in the literature.

Relevance of bacterial cultures of abdominal aortic aneurysm contents.

BACKGROUND: To establish further insight into the relevance of intraoperative bacterial cultures of abdominal aortic aneurysm contents a study was performed of the rate of occurrence of prosthetic graft infection after aneurysm repair. METHODS: Bacterial cultures were obtained from 216 patients, who were followed up for more than 3.5 years after operation and studied retrospectively in a single center analysis. RESULTS: Thrombus cultures yielded bacteria in 55 of 216 (25.5%) cases, including 11 of 44 (25%) cases with ruptured aneurysms. Prosthetic infections (4 of 216; 1.9%) occurred more frequently (p < 0.02) in patients with positive thrombus cultures (3 of 55; 5.5%) than in patients with negative cultures (1 of 161; 0.6%). In two patients the species isolated from the thrombus was also cultured from the vascular prosthesis, although in one graft infection other organisms were also isolated. CONCLUSIONS: The presence of bacteria in the intraluminal thrombus does not appear to be an important factor in the development of graft infection after primary elective and urgent abdominal aortic aneurysm repair. Therefore routine intraoperative cultures are unnecessary unless clinical signs of infective aortitis are present.

Legionella monitoring: a continuing story of nosocomial infection prevention.

Of 21 cases of legionellosis, 14 were of nosocomial origin and 6 others had a possible nosocomial source. The hot and cold water systems, respiratory therapy equipment, puddles of rain water on flat roofs and in gutters, and demineralized water systems were all excluded as a source of nosocomial infection. By subtyping it was shown that Legionella pneumophila serogroup 1 isolates from 11 patients and from the cooling towers were indistinguishable. Because of this result the cooling towers were considered to be the infection source. After effective chlorination of the cooling towers, the frequency of legionellosis declined.

Mupirocin resistance in coagulase-negative staphylococci, after topical prophylaxis for the reduction of colonization of central venous catheters.

Topical mupirocin was routinely applied to insertion sites of central venous catheters (CVC) of neonates in a neonatal intensive care unit. After five years, mupirocin resistance was recorded in 42% of clinical isolates of coagulase-negative staphylococci (CNS). This decreased to 21% during a mupirocin-free interval of five months. We performed a prospective study on the significance of mupirocin use on the staphylococcal skin flora of 15 newly admitted neonates. During treatment, mupirocin-susceptible strains were replaced by highly resistant ones. After treatment, all but one neonate harboured at least one resistant strain; 29% of all strains were moderately resistant (mupirocin minimum inhibitory concentrations (MICs) 16 mg/L) and 55% were highly resistant (MICs > 1024 mg/L). One CVC (7%) became colonized with a resistant strain. One year after stopping routine mupirocin application the incidence of resistance had dropped to 13%; CVC colonization was recorded in 2.4%.

Enterobacter cloacae outbreak in the NICU related to disinfected thermometers.

In the first week ot December 1997, an increasing incidence of neonates colonized with multi-drug resistant Enterobacter cloacae (MR-E. cloacae) was observed in the neonatal Intensive care unit of our 950-bed university hospital. Initially, re-enforcement of infection control practices including hand disinfection and cohort isolation seemed to be sufficient to control the outbreak. Nevertheless, an increasing number of newly admitted patients was paralleled by another rise in the incidence of colonized neonates. Since E. cloacae was initially found in urine specimens of the patients, surveillance and environmental cultures were aimed at procedures and instruments that might colonize the gastro-intestinal and/or urinary tract. E, cloacae was isolated from a single cap of an electronic digital thermometer. Despite banning of this possible source, newly admitted neonates still became colonized. The unit was closed for further admissions and a second round of extensive screening was started; this time including all available thermometers and continuous rectal temperature probes. Ready-to-use 'disinfected thermometers and probes were found to be colonized with MR-E. cloacae. Observation of disinfection procedures and a laboratory investigation revealed that 'rushed disinfection with alcohol 80% led to a 1 in 10 chance of thermometers still being contaminated. Furthermore, alcoholic hand rub used for convenience disinfection failed to disinfect thermometers in 40% and 20% of the cases when done in a 'rushed' or 'careful' fashion, respectively. Adequate disinfection of the thermometers led to the control of the outbreak, with no new occurrence of MR-E. cloacae in the following months.

Bacteraemia caused by Stomatococcus mucilaginosus in a granulocytopenic patient with acute lymphocytic leukaemia.

A patient undergoing chemotherapy for acute lymphoblastic leukaemia developed bacteraemia caused by Stomatococcus mucilaginosus while he was granulocytopenic. The organism may have been selected from the upper respiratory tract flora during prophylaxis with oral ciprofloxacin and then translocated to the blood stream via the mucosa. The strain produced an API-Staph profile indistinguishable from that of Micrococcus kristinae. Since a catalase-negative reaction is highly suggestive of S. mucilaginosus, the test should be performed routinely if this organism is not to be overlooked.

Sensitivity of intrapartum group B streptococcal screening and in vitro comparison of four rapid antigen tests.

OBJECTIVES: To evaluate the sensitivity of intrapartum screening for group B streptococcal (GBS) colonization and to compare 4 rapid GBS antigen tests in vitro. DESIGN: Two swabs of the lower vagina of 769 parturients were taken; one swab was cultured, the other was frozen at -70 degrees C until antigen testing with the Group B Strep Test (Quidel) of the culture positive samples was performed. The Quidel test was then compared with 3 other rapid GBS antigen tests in vitro: Wellcogen Strep B (Wellcome Diagnostics), Slidex méningite Strepto B (bioMérieux) and ICON Strep B (Hybritech). The supernatant of 29 GBS cultures in Todd-Hewitt broth was tested in bacterial concentrations of 10(6), 10(7), and 10(8) Colony-forming Units (CFU)/ml, respectively. RESULTS: Lower vagina GBS carrier rate was 13.4% (103/769) and heavy colonization (growth density 3 and 4 on blood agar plates) was found in 5.2% (40/769). The Group B Strep Test detected 11% (11/103) of GBS carriers, with a sensitivity for heavy colonization of 25% (10/40). In vitro none of the tests scored positively with a concentration of 10(6) CFU/ml, while with 10(7) CFU/ml the enzyme immunoassay tests (Quidel, Hybritech) were more sensitive (McNemar test, P < 0.05) than the latex agglutination tests (Wellcome Diagnostics, bioMérieux). CONCLUSIONS: Although in vitro the enzyme immunoassay tests are more sensitive than the latex agglutination tests, sensitivity in vivo is too low to recommend the use of rapid antigen tests for general screening.

Randomized study of vaginal chlorhexidine disinfection during labor to prevent vertical transmission of group B streptococci.

OBJECTIVE: To evaluate the effect of vaginal disinfection with chlorhexidine gel during labor on vertical transmission of group B streptococcus, as a method to prevent vertical transmission and subsequent neonatal early onset group B streptococcal disease. STUDY DESIGN: A prospective study with randomization of 1020 parturients to one of three groups as soon as labor started. In all parturients, anus, introitus and cervix were cultured semiquantitatively. Two groups were treated double-blindly with 10 ml of either a 0.3% chlorhexidine gel or a placebo gel, applicated around the portio and into the fornices. If labor still continued, a second application was given after 10 h. The third group received no treatment. Ear, pharynx and umbilicus of all newborns were also cultured semiquantitatively. RESULTS: Nine hundred and eighty one women were evaluated. The overall incidence of group B streptococcal carriership was 19.4%. Vertical transmission was 52.4% in the chlorhexidine group, 71.4% in the placebo group and 66.7% in the control group (P = 0.069). When testing the transmission rates for the chlorhexidine versus the combined placebo plus control group (69.3%), the difference was 16.9% (P = 0.026). CONCLUSION: Vaginal disinfection with a chlorhexidine gel during labor modestly reduces group B streptococcal vertical transmission. Because the method is cheap, simple and safe, it should be considered for routine use. Our results indicate that it may reduce the incidence of early onset group B streptococcal sepsis by 2-32%.

Recurrent therapy resistant mastoiditis by Mycobacterium cheilonae abscessus, a nontuberculous mycobacterium.

A rare case of recurrent mastoiditis is described with abscess formation caused by a nontuberculous mycobacterium (NTM) Mycobacterium chelonae abscessus. The exceptionally slow wound healing after repeated surgical debridement was striking. A literature study showed that in contrast with NTM infections of other parts of the body, infections of the middle ear were most commonly seen in immunocompetent children. If a case of chronic unilateral otitis media shows insufficient response to antibiotic therapy and surgical debridement, mycobacterial infection should be considered. The case described below illustrates the importance of histopathological and microbiological investigations.

[Neonatal meningitis: is the combination ampicillin-gentamycin obsolete?]. / Neonatale meningitis: is de combinatie ampicilline-gentamicine achterhaald?

The course of E. coli-meningitis in two infants, treated with latamoxef (moxalactam) in combination with ampicillin is described. Because of the disappointing results the potential value of latamoxef for therapy of Gram-negative enteric meningitis of infancy is discussed.

[An alternative method for the collection of blood cultures in newborn infants]. / Een 'alternatieve' methode voor het afnemen van bloedkweken bij pasgeborenen.

Diagnostic proof of septicemia depends on the results of blood cultures. In the neonatal period it is, however, difficult to obtain venous blood. Capillary sampling of a small volume of blood from a heel-prick, performed with a suitable instrument, can be a reliable alternative. This is concluded from a series of 67 paired blood cultures, after comparison with data obtained from the literature.

[Neonatal meningitis caused by Enterobacter sakazakii: milk powder is not sterile and bacteria like milk too!]. / Neonatale meningitis door Enterobacter sakazakii: melkpoeder is niet steriel en bacteriën lusten ook melk!

Powdered milk for infants can contain very low numbers of Enterobacter sakazakii. Larger amounts of this organism can result in non-infective colonization. In infants, particularly the premature newborn, such colonization has been associated with abdominal distention and bloody diarrhoea or bacteriuria, but cases of sepsis and meningitis have also been reported. Infection has been associated with the use of contaminated spoons or blenders as well as the habit of keeping the ready-made milk hot in bottle-heaters. The risk of contamination of the milk can be eliminated by boiling bottles, teats and spoons as well as disinfecting the blender before use. The possibility of bacterial replication can be significantly reduced by keeping the ready-made milk in a refrigerator and warming it up immediately before use eg by using a microwave oven.