AUTHOR SECTION patients who may be treated in the outpatient setting with oral M antimicrobials from patients in whom hospitalization and parenteral therapy is appropriate. Over the past decade, dramatic escalation in antimicrobial resistance among common respiratory pathogens poses Macartney K.K. et al. Nosocomial respiratory syncytial virus infections: the obstacles to antibiotic choices.We review the microbiology of com- cost-effectiveness and cost-benefit of infection control. Pediatrics. 2000; munity-acquired pneumonia, and the therapeutic strategies that are 106(3) : 520-6.p Abstract: OBJECTIVE:To determine the cost- clinically and cost effective. effectiveness and cost-benefit of an infection control program to reduce nosocomial respiratory syncytial virus (RSV) transmission in Lyon W.R. et al. A role for trigger factor and an rgg-like regulator in the tran- a large pediatric hospital. DESIGN: RSV nosocomial infection (NI) scription, secretion and processing of the cysteine proteinase of Streptococcus was studied for 8 years, before and after intervention with a target- pyogenes. EMBO J. 1998; 17(21) : 6263-75.p Abstract: The abili- ed infection control program.The cost-effectiveness of the interven- ty of numerous microorganisms to cause disease relies upon the tion was calculated, and cost-benefit was estimated by a case-control highly regulated expression of secreted proteinases. In this study, comparison. SETTING: Children’s Hospital of Philadelphia, a 304- mutagenesis with a novel derivative of Tn4001 was used to identify bed pediatric hospital. PATIENTS: All inpatients with RSV infec- genes required for the expression of the secreted cysteine proteinase tion, both community- and hospital-acquired. INTERVENTION: (SCP) of the pathogenic Gram-positive bacterium Streptococcus Consisted of early recognition of patients with respiratory symp- pyogenes. Designated as Rop loci (regulation of proteinase), ropB is toms, confirmation of RSV infection by laboratory testing, estab- a rgg-like transcriptional activator required for transcription of the lishing cohorts of patients and nursing staff, gown and glove barrier gene which encodes the proteinase. In contrast, ropA contributes precautions, and monitoring and education of staff. OUTCOME post-transcriptionally to the secretion and processing of SCP and MEASURES:The incidence density of RSV NI before and after the encodes a homologue of Trigger Factor, a peptidyl-prolyl isomerase intervention was calculated as the rate per 1000 patient days-at-risk and putative chaparone which is highly conserved in most bacterial for infection. Intervention costs included laboratory testing, isola- species, but of unknown function. Analysis of additional ropA tion, and administration of the program. The cost of RSV NI was mutants demonstrated that RopA acts both to assist in targeting SCP estimated by comparing hospital charges for 30 cases and matched to the secretory pathway and to promote the ability of the propro- uninfected controls. RESULTS:A total of 148 patients acquired NI tein to establish an active conformation upon secretion. This latter (88 before and 60 after the intervention). The Mantel-Haenszel function was dependent upon the peptidyl-prolyl isomerase domain stratified relative risk for NI in the period before the infection con- of RopA and mutants that lacked this domain exhibited a bipartite trol program, compared with the postintervention period, was.61 deficiency manifested as a kinetic defect in autologous processing of (95% confidence interval:.53-.69). By applying the preintervention the proprotein to the mature proteinase, and as a catalytic defect in stratum-specific rates of infection to the days-at-risk in the postin- the mature proteinase.These results provide insight into the function tervention period, an estimated 100 NIs would have been expected, of Trigger Factor, the regulation of proteinase activity and the mech- which in comparison to the 60 NIs observed, yielded an estimated anism of secretion in Gram-positive bacteria. program effectiveness of 10 RSV NIs prevented per season.The total cost of the program per season was $15 627 or $1,563/NI prevent- Lysenko E.S. et al. Bacterial phosphorylcholine decreases susceptibility to the ed. In comparison, the mean cost to the hospital was $9,419/case of antimicrobial peptide LL-37/hCAP18 expressed in the upper respiratory RSV NI, resulting in a cost-benefit ratio of 1:6. CONCLUSIONS: tract. Infect Immun. 2000; 68(3) : 1664-71.p Abstract: A number A targeted infection control intervention was cost-effective in of pathogens of the upper respiratory tract express an unusual reducing the rate of RSV NI. For every dollar spent on the program, prokaryotic structure, phosphorylcholine (ChoP), on their cell sur- approximately $6 was saved. face.We tested the hypothesis that ChoP,also found on host mem- brane lipids in the form of phosphatidylcholine, acts so as to decrease Macdonald S. et al. Comparison of technical success and outcome of tunneled killing by antimicrobial peptides that target differences between bac- catheters inserted via the jugular and subclavian approaches. J Vasc Interv terial and host membranes. In Haemophilus influenzae, ChoP is a Radiol. 2000; 11(2 Pt 1) : 225-31.p Abstract: PURPOSE: To phase-variable structure on the oligosaccharide portion of the compare the technical success and immediate and long-term out- lipopolysaccharide (LPS).There was a bactericidal effect of the pep- comes of tunneled central venous catheters placed in comparative tide LL-37/hCAP18 on a nontypeable H. influenzae strain, with an cohorts via the subclavian vein (SCV) and the internal jugular vein increasing selection for the ChoP(+) phase as the concentration of (IJV) routes. MATERIALS AND METHODS:This was a prospec- the peptide was raised from 0 to 10 microgram/ml. Moreover, con- tive observational single-center study of consecutive procedures. stitutive ChoP-expressing mutants of unrelated strains showed up to Between November 1993 and June 1995, 99 catheters were placed 1,000-fold-greater survival compared to mutants without ChoP.The via the SCV and between December 1997 and July 1998, 109 effect of ChoP on resistance to killing by LL-37/hCAP18 was catheters were placed via the IJV.Procedural data were recorded in dependent on the salt concentration and was observed only when both cohorts by completion of a proforma by the primary operator. bacteria were grown in the presence of environmental choline, a RESULTS: Follow-up data were available in 96% of the SCV and requirement for the expression of ChoP on the LPS. Further studies 87% of the IJV cohorts.The average procedure time was significant- established that there is transcription of the LL-37/hCAP18 gene on ly shorter in the IJV group and technical success was 100% versus the epithelial surface of the human nasopharynx in situ and 97% in the SCV group, but this did not reach statistical significance. inducible transcription in epithelial cells derived from the upper air- The procedure-related pneumothorax rate and the rate of sympto- way.The presence of highly variable amounts of LL-37/hCAP18 in matic venous thrombosis were significantly lower in the IJV cohort normal nasal secretions (<1.2 to >80 microgram/ml) was demon- (P =.023, P =.015). Fewer catheters were removed prematurely due strated with an antibody against this peptide. It was concluded that to sepsis in the IJV group (P =.043). CONCLUSIONS: The IJV ChoP alters the bacterial cell surface so as mimic host membrane route is associated with comparable technical success, and lower lipids and decrease killing by LL-37/hCAP18, an antimicrobial pep- major procedural complication and venous thrombosis rates, with tide that may be expressed on the mucosal surface of the nasophar- fewer catheters removed prematurely.The right IJV approach with ynx in bactericidal concentrations. ultrasound guidance is recommended as the route of choice for the placement of tunneled central venous catheters. MacGowan A. et al. External quality assessment of the serum bactericidal test: results of a methodology/interpretation questionnaire. J Antimicrob Chemother. 1997; 39(2) : 277-84.p Abstract: Two hundred micro- 511 ANTIMICROBIAL RESISTANCE BIBLIOGRAPHY biology laboratories in the UK took part in two separate experi- results, host factors, and antibiotic characteristics. Initially, antibiotics mental external quality assessment distributions related to the serum are chosen on the basis of the organisms that are suspected to be caus- bactericidal test (SBT). In the first, Staphylococcus aureus NCTC ing the infection. Once the infecting organism(s) is isolated and sensi- 6571 (vancomycin MIC 1 mg/L), was tested against a human serum tivities are established, the initial antibiotic(s) may be modified. In containing vancomycin 38 mg/L plus gentamicin 0.5 mg/L. In the selecting specific antibiotics for the treatment of osteomyelitis,the type second, Streptococcus oralis PAJ 112/4183 (penicillin MBC < or = of infection, current hospital sensitivity resistance patterns, and the risk 0.03 mg/L) and Streptococcus sanguis PAJ 107/4184 (penicillin of adverse reactions must be strongly appraised.Antibiotic classes used MBC = 128 mg/L) were tested against human serum containing in the treatment of osteomyelitis include penicillins, beta-lactamase penicillin 15 mg/L. Respondents returned their laboratory results inhibitors, cephalosporins, other beta-lactams (aztreonam and imipen- and a questionnaire on clinical interpretation and