Oropharyngeal Gram-negative bacillary carriage: a survey of 120 healthy individuals.

BACKGROUND: The presence of aerobic Gram-negative bacilli (AGNB) in the oropharynx can be either temporary or persistent. Prolonged colonization (ie, carriage) is distinguished from transient presence (ie, acquisition), which often occurs in healthy individuals but less frequently in those with underlying disease. Prevalence rates of up to 61.1% quoted previously for healthy individuals were obtained by using single sample surveys, which fail to differentiate acquisition from carriage. STUDY OBJECTIVES: To illustrate the need to distinguish carriage from acquisition in a healthy population at risk of acquisition of AGNB, and to show that although differing groups of healthy individuals may acquire oropharyngeal AGNB at differing frequencies, carriage is rare in healthy individuals. PARTICIPANTS: Two oral rinses were obtained within a 2-day interval from 120 healthy individuals comprising 40 nurses, 40 students, and 40 laboratory-associated persons. DESIGN: Two hundred forty oral rinses were quantitatively (1:10 dilution series) cultured for AGNB by using broth enrichment. MEASUREMENTS AND RESULTS: The rate of AGNB carriage based on two consecutive samples positive for the same AGNB was 6.6%; the rate of AGNB acquisition based on one positive sample was 35.8%. The concentrations of all carried and acquired AGNB were < or = 103 cfu/mL. AGNB acquisition was significantly higher in students (52.5%) compared to nurses (32.5%) and laboratory-associated persons (22.5%; p < 0.05). CONCLUSION: Healthy individuals rarely carry oropharyngeal AGNB, suggesting effective oropharyngeal clearance in a healthy population predisposed to acquisition. Apparently, the oropharyngeal mucosa in healthy individuals is not receptive to adhesins of AGNB, resulting in rapid elimination of these bacteria.

Oropharyngeal gram-negative bacillary carriage in chronic obstructive pulmonary disease: relation to severity of disease.

The prolonged presence of aerobic Gram-negative bacilli (AGNB) in the oropharynx is termed 'carriage'. AGNB carriage rates are low in populations of healthy individuals. Previously, severity of underlying disease has been positively correlated with oropharyngeal AGNB carriage rate. Overgrowth of AGNB at the oropharynx poses a significant risk of endogenous infection in end-stage chronic obstructive pulmonary disease (COPD) patients. The aims of this study were to undertake an epidemiological survey of the oropharyngeal flora of COPD patients and to correlate oropharyngeal carriage of AGNB with severity of disease. Two oral rinses were obtained, within a 2-day interval, from 40 COPD patients comprising three disease severity groups: 1. mild, 2. moderate and 3. severe. Eighty oral rinses were quantitatively (1:10 dilution series) cultured for AGNB and yeasts using broth enrichment. The mean AGNB carriage rate was 15%. AGNB carriage rates of 0, 7.7 and 29.4% were observed within the mild, moderate and severe disease groups, respectively. The mean yeast carriage rate was 33.3%. Yeast carriage rates of 33.3, 15.4 and 64.7% were observed within the mild, moderate and severe disease groups, respectively. Carriage of Staphylococcus aureus was 5%. Rates of oropharyngeal carriage of AGNB (1/23 vs. 5/17) and yeasts (5/23 vs. 11/17) were significantly higher within the severe disease group than in non-severe disease groups. Oropharyngeal carriage of AGNB in end-stage COPD patients (forced expiratory volume in 1 sec, FEV1 < 50% predicted) presents a potential source of Gram-negative endogenous pneumonia. This outcome may be promoted by intubation and some flora-suppressing antibiotic therapies.

Myositis in children with meningococcal disease: a role for tumour necrosis factor-alpha and interleukin-8?

OBJECTIVES: Myalgia is under-recognized in meningococcal disease (MCD). In septic shock, myositis is thought to be mediated by pro-inflammatory cytokines such as tumour necrosis factor-alpha (TNF-alpha), interleukin-8 (IL-8) and interleukin-6 (IL-6) but this has never previously been studied in MCD. We aimed to demonstrate whether muscle damage mediated via TNF-alpha and other pro-inflammatory cytokines occurs in MCD, as estimated by creatine kinase skeletal muscle isoenzyme (CK-MM) and cardiac isoenzyme (CK-MB) concentrations. METHODS: A total of 68 children, median age 2.7 years, with a diagnosis of MCD were prospectively studied. Severity of disease was measured using the Glasgow Meningococcal Septicaemia Prognostic Score (GMSPS). Severe disease was defined as a GMSPS of > or =8. TNF-alpha, IL-8, IL-6 and IL-1Ra concentrations were determined on samples taken on admission. RESULTS: CK-MM correlated significantly with TNF-alpha, IL-8 and GMSPS. There was no significant correlation between CK-MB and TNF-alpha or IL-6, but CK-MB correlated with GMSPS and IL-8. Fifty-six percent of children with MCD had evidence of muscle damage as manifested by elevated CK-MM. CONCLUSIONS: TNF-alpha and IL-8 may be potential mediators in the pathophysiology of skeletal muscle damage in MCD.

Assessment of the immunocontraceptive effect of a zona pellucida 3 peptide antigen in wild mice.

Immunizing laboratory mice against a short peptide to mouse zona pellucida protein 3 (mZP3; amino acids 328-342) reduces fertility in some strains. This antigen was therefore tested to see if it is suitable for use in an immunocontraceptive vaccine to control wild mice. Mouse zona pellucida protein 3 peptide conjugated to a carrier protein (keyhole limpet hemocyanin) was considerably more immunogenic and effective in reducing fertility in wild mice when compared with inbred BALB/c mice. Fertility of the immunized wild mice was reduced by over 50% compared with controls, whereas BALB/c mice showed no reduction. Variation in the responses between individual animals to mZP3 peptide was observed and infertility correlated to the presence of cross-reacting antibodies to native zona pellucida in wild, but not BALB/c, mice.

Expression of recombinant mouse sperm protein sp56 and assessment of its potential for use as an antigen in an immunocontraceptive vaccine.

Recombinant mouse sp56 protein was produced for testing as an antigen in an immunocontraceptive vaccine. The coding sequence for the mature sp56 protein was cloned into the bacterial expression system pFLAG using a PCR-based method on mouse testis cDNA. Polyclonal antisera were raised in mice against affinity purified recombinant sp56 fusion protein (sp56FLAG) or an artificial sp56 peptide fused to a carrier protein (KLH) and shown to cross-react to a protein band of 75 kD in detergent extracts of mouse sperm by Western immunoblot analysis under reducing conditions. The antisera to sp56FLAG also immunolocalized over the entire acrosome of mouse sperm. Female BALB/c mice were immunized intraperitoneally with sp56FLAG in a fertility trial with 20 microg sp56FLAG in Freund's Complete Adjuvant and boosted three to five times with 20 microg sp56FLAG in Freund's Incomplete Adjuvant. Litter sizes of sp56FLAG-treated mice were significantly smaller than control-treated animals after five boosts.

The role of RANTES in meningococcal disease.

The chemokine RANTES (regulated on activation, normal T cell expressed and secreted) is a potent regulator of leukocyte trafficking. RANTES preferentially attracts mature CD4 cells as well as macrophages and eosinophils, but not neutrophils. In total, 128 children with meningococcal disease were prospectively studied, and the role of RANTES in the pathophysiology of meningococcal disease was assessed. Plasma RANTES, interleukin (IL)-8, IL-6, IL-1 receptor agonist, and tumor necrosis factor-alpha were measured at admission. Severity of disease was stratified by the Glasgow meningococcal septicemia prognostic score (GMSPS). RANTES levels correlated significantly with IL-8 levels, admission lactate levels, platelets, prothrombin time, and activated partial thromboplastin time. RANTES levels were lower in children with severe disease (GMSPS>/=8; P=.001), in those with septic shock (P<.0005), and in nonsurvivors (P=.048; Mann-Whitney test). RANTES is a potential mediator in the pathophysiology of meningococcal disease.