Palmitoyl acyltransferase DHHC21 mediates endothelial dysfunction in systemic inflammatory response syndrome.

Endothelial dysfunction is a hallmark of systemic inflammatory response underlying multiple organ failure. Here we report a novel function of DHHC-containing palmitoyl acyltransferases (PATs) in mediating endothelial inflammation. Pharmacological inhibition of PATs attenuates barrier leakage and leucocyte adhesion induced by endothelial junction hyperpermeability and ICAM-1 expression during inflammation. Among 11 DHHCs detected in vascular endothelium, DHHC21 is required for barrier response. Mice with DHHC21 function deficiency (Zdhhc21dep/dep) exhibit marked resistance to injury, characterized by reduced plasma leakage, decreased leucocyte adhesion and ameliorated lung pathology, culminating in improved survival. Endothelial cells from Zdhhc21dep/dep display blunted barrier dysfunction and leucocyte adhesion, whereas leucocytes from these mice did not show altered adhesiveness. Furthermore, inflammation enhances PLCß1 palmitoylation and signalling activity, effects significantly reduced in Zdhhc21dep/dep and rescued by DHHC21 overexpression. Likewise, overexpression of wild-type, not mutant, PLCß1 augments barrier dysfunction. Altogether, these data suggest the involvement of DHHC21-mediated PLCß1 palmitoylation in endothelial inflammation.

Vagococcus carniphilus sp. nov., isolated from ground beef.

Nine enterococcus-like strains were referred to the Streptococcus Laboratory at the Centers for Disease Control and Prevention (CDC) for further identification from the National Antimicrobial Resistance Monitoring System Laboratory at the CDC. The cultures were isolated from ground beef purchased from retail in Oregon in 2000. Conventional biochemical testing and analysis of whole-cell protein electrophoretic profiles distinguished these strains from known species of enterococci and vagococci. Comparative 16S rRNA gene sequencing studies revealed that these strains were most closely related to the species Vagococcus fluvialis. DNA-DNA reassociation studies confirmed that these nine strains represented a new taxon. The relative binding ratio was 87 % or greater at the optimal temperature, and the divergence was less than 1 % for strains hybridized against the isolate designated the type strain. DNA-DNA relatedness was 25 % to V. fluvialis and 9 % or less to the other three species of Vagococcus. DNA-DNA relatedness was 33 % or less to the 25 currently described species of Enterococcus. On the basis of this evidence, it is proposed that these strains be classified as Vagococcus carniphilus sp. nov. The type strain of V. carniphilus is 1843-02T (= ATCC BAA-640T = CCUG 46823T). The clinical significance (if any) of these strains is yet to be determined.

An outbreak of conjunctivitis due to atypical Streptococcus pneumoniae.

BACKGROUND: In February 2002, clinicians at the Dartmouth College Health Service recognized an outbreak of conjunctivitis; cultures of conjunctival swabs implicated Streptococcus pneumoniae. An investigation was begun to determine the extent of the outbreak, confirm the cause, identify modes of transmission, and implement control measures. METHODS: Investigators reviewed the health service's data base for diagnoses of conjunctivitis. Viral and bacterial cultures were obtained from ill students. Bile-soluble isolates that were susceptible to ethylhydrocupreine (optochin) and therefore were presumed to be pneumococci underwent serotyping, capsular staining, pulsed-field gel electrophoresis, a DNA probe, and multilocus sequence typing. A cohort study of risk factors was conducted with the use of the Internet. Control measures included distribution of alcohol-based hand gel and messages about prevention. RESULTS: Among 5060 students, 698 (13.8 percent) received a diagnosis of conjunctivitis from January 1, 2002, through April 12, 2002, including 22 percent of first-year students. Presumed pneumococci were isolated from 43.3 percent of conjunctival swabs (110 of 254); viral cultures performed on 85 specimens were negative. DNA probes and multilocus sequence typing confirmed that the organisms were pneumococci, although the bacteria did not have the characteristic capsule. On pulsed-field gel electrophoresis, strains were found to be identical to pneumococci that caused outbreaks of conjunctivitis in other parts of the country in 1980. Analysis of survey data from 1832 students indicated that close contact with a student with conjunctivitis, wearing contact lenses, membership on a sports team, and attending parties at or living in a fraternity or sorority house were associated with conjunctivitis. The rate of diagnosis of conjunctivitis declined after the implementation of control measures and after spring break. CONCLUSIONS: This large outbreak of conjunctivitis on a college campus was caused by an atypical, unencapsulated strain of S. pneumoniae that was identical to strains that had caused outbreaks two decades earlier.

Pulsed-field fingerprinting of vaginal group B streptococcus in pregnancy.

OBJECTIVE: There is more to be learned about the epidemiology of group B beta-hemolytic streptococci infections in pregnancy. In this study, we investigated the discriminating capabilities of pulsed-field gel electrophoresis of group B streptococci strains from pregnant patients and mother/infant pairs of patients compared with serotyping. METHODS: Forty-two vaginal strains of group B streptococci cultured from pregnant patients in the third trimester and strains from 20 mother/infant pairs with documented newborn group B streptococci infection were studied. Isolates were serotyped by the Lancefield capillary precipitin method and molecularly characterized by counterclamped homogeneous electrical field pulsed-field gel electrophoresis with rarely cutting restriction enzymes. RESULTS: Nine of the 13 serotypes of group B streptococci identified thus far in the scientific literature (Ia, Ia/c, Ib, Ib/c, II, IIc, III, V, and NT/c) were represented among the 62 isolates. Among the 42 maternal isolates, eight serotypes were represented, and among the 20 mother/infant isolates, six serotypes were represented. Serotypes of mother/infant isolates matched in nine of the ten pairs. Restriction endonuclease profiles, or digests, from the 42 maternal isolates resulted in 25 unique profiles that were arranged into five major groups based on the overall relatedness. Each group was comprised of one predominant serotype. The 20 mother/infant paired isolates displayed nine unique restriction endonuclease profiles and nine of the ten paired isolates showed indistinguishable restriction endonuclease profiles between mother and infant. CONCLUSION: Deoxyribonucleic acid profiling using pulsed-field gel electrophoresis is more discriminating of group B streptococci strains than serotyping because of the different yet closely related patterns within each restriction endonuclease profile group that are linked to one specific serotype. Pulsed-field gel electrophoresis can refine our epidemiologic studies of group B streptococci transmission and acquisition.

Recurrent invasive pneumococcal disease in individuals with human immunodeficiency virus infection.

The proportion of relapses and reinfections that are potentially preventable by vaccine in human immunodeficiency virus (HIV)-infected persons with recurrent pneumococcal disease is unknown. Isolates from HIV-infected individuals from Baltimore with recurrent pneumococcal invasive disease were collected from 1 January 1995 through 31 December 2000. Serotyping and pulsed-field gel electrophoresis were performed. From 1 January 1995 through 31 December 1998, 14.9% (404/2717) of those who had a pneumococcal infection were HIV infected. The recurrence rate among HIV-infected individuals was 6.4-fold higher than that among individuals without HIV infection (P<.01). Among recurrent infections in 41 individuals, there were 42 reinfections and 6 relapses. All relapses and 91% (70/77) of reinfections were due to serotypes covered by the 23-valent pneumococcal polysaccharide vaccine. Reinfection was more common than relapse among HIV-infected individuals with recurrent pneumococcal disease. Although a substantial proportion of recurrent pneumococcal infections was potentially preventable by vaccine, creating an effective vaccine may be challenging for this population.

Distribution of penicillin-nonsusceptible pneumococcal clones in the Baltimore metropolitan area and variables associated with drug resistance.

We assessed the distribution of the clonal groups (as determined by pulsed-field gel electrophoresis) of penicillin-nonsusceptible Streptococcus pneumoniae that caused invasive pneumococcal infection in the Baltimore metropolitan area during 1995 and 1996. Although S. pneumoniae caused invasive disease in individuals from a variety of demographic groups and locations, strains isolated during the season in which respiratory infections are most common were more likely to be from clonal groups associated with penicillin resistance than from other groups.