Detection of Salmonella Enteritidis (SE) bacterin in environmental samples from poultry houses using the RapidChek SE immunoassay.

Environmental swabs from pullet houses were tested for the presence of Salmonella Enteritidis (SE) using the RapidChek SE immunoassay test. Of the 1162 samples tested in 2011, 20 samples were positive, but only two samples were confirmed positive for SE by culture. Seventeen positive samples were from pullet houses that had been vaccinated with SE bacterin 2 to 3 days prior to submission to the lab. This study investigated the detection of SE bacterin using the RapidChek SE test system. Swabs were inoculated with different amounts of a commercial SE bacterin. As little as 0.25 ml of the SE bacterin was sufficient to cause positive results with the RapidChek SE test. This finding emphasizes the need to perform bacterial isolation and identification when a positive result occurs using an immunoassay test.

Evaluation of human immunodeficiency virus and hepatitis C telemedicine clinics.

BACKGROUND: Geographical barriers to subspecialty care may prevent optimal care of patients living in rural areas. We assess the impact of human immunodeficiency virus (HIV) and hepatitis C telemedicine consultation on patient-oriented outcomes in a rural Veterans Affairs population. METHODS: This was a pre- and post-intervention study comparing telemedicine with in-person subspecialty clinic visits for HIV and hepatitis C. Eligible patients resided in 2 rural catchment areas. The primary binary outcome was clinic completion. We estimated a logistic regression model with patient-level fixed effects. This approach controls for the clustering of visits by patient, uses each patient's in-person clinic experience as an internal control group, and eliminates confounding by person-level factors. We also surveyed patients to assess satisfaction and patient-perceived reductions in health visit-related time. RESULTS: There were 43 patients who accounted for 94 telemedicine visits and 128 in-person visits. Clinic completion rates were higher for telemedicine (76%) than for in-person visits (61%). In regression analyses, telemedicine was strongly predictive of clinic completion (OR 2.2; 95% confidence interval [CI]: 1.0-4.7). The adjusted effect of telemedicine on clinic completion rate was 13% (95% CI: 12-13). Of the 30 patients (70%) who completed the survey, more than 95% rated telemedicine at the highest level of satisfaction and preferred telemedicine to in-person clinic visits. Patients reported a significant reduction in health visit-related time (median 340 minutes, interquartile range 250-440), mostly due to decreased travel time. CONCLUSIONS: HIV and hepatitis C telemedicine clinics are associated with improved access, high patient satisfaction, and reduction in health visit-related time.

Modulation of virulence gene expression in Staphylococcus aureus by interleukin-1beta: novel implications in bacterial pathogenesis.

The effect of IL-1beta on Staphylococcus aureus was investigated in terms of mRNA expression profile of bicomponent leukotoxins (Luk ED, Luk PV, HlgA, and HlgCB) as well as microbial surface components recognizing adhesive matrix molecules (MSCRAMMs). Upon exposure to higher concentrations of IL-1beta, S. aureus expressed significantly higher levels of MSCRAMMs mRNA [fibronectin-binding protein (FnBp), fibrinogen-binding protein or clumping factor (Clf), and collagen-binding protein (Cna)] and had significantly lower expression of mRNAs for bicomponent leukotoxins. Sequential in vitro passing of S. aureus in the absence of rhIL-1beta resulted in reduced binding to rhIL-1beta resulted in lack of significant changes in virulence gene expression upon exposure to low or high concentrations of rhIL-1beta. It is possible that IL-1beta modulates the pathogenic potential of S. aureus by altering its virulence gene expression to adapt to the host's inflammatory micromilieu. The ability to express higher levels of MSCRAMMs and low levels of leukotoxins might contribute towards the successful invasion and persistence of S. aureus in chronic inflammatory conditions. Determination of the mechanisms of IL-1-induced alterations in S. aureus gene expression may lead to the identification of novel therapeutic targets against this ever-evolving opportunistic pathogen.

Campylobacter jejuni strains compete for colonization in broiler chicks.

Campylobacter jejuni isolates possess multiple adhesive proteins termed adhesins, which promote the organism's attachment to epithelial cells. Based on the proposal that one or more adhesins are shared among C. jejuni isolates, we hypothesized that C. jejuni strains would compete for intestinal and cecal colonization in broiler chicks. To test this hypothesis, we selected two C. jejuni strains with unique SmaI pulsed-field gel electrophoresis macrorestriction profiles and generated one nalidixic acid-resistant strain (the F38011 Nal(r) strain) and one streptomycin-resistant strain (the 02-833L Str(r) strain). In vitro binding assays revealed that the C. jejuni F38011 Nal(r) and 02-833L Str(r) strains adhered to LMH chicken hepatocellular carcinoma epithelial cells and that neither strain influenced the binding potential of the other strain at low inoculation doses. However, an increase in the dose of the C. jejuni 02-833L Str(r) strain relative to that of the C. jejuni F38011 Nal(r) strain competitively inhibited the binding of the C. jejuni F38011 Nal(r) strain to LMH cells in a dose-dependent fashion. Similarly, the C. jejuni 02-833L Str(r) strain was found to significantly reduce the efficiency of intestinal and cecal colonization by the C. jejuni F38011 Nal(r) strain in broiler chickens. Based on the number of bacteria recovered from the ceca, the maximum number of bacteria that can colonize the digestive tracts of chickens may be limited by host constraints. Collectively, these data support the hypothesis that C. jejuni strains compete for colonization in chicks and suggest that it may be possible to design novel intervention strategies for reducing the level at which C. jejuni colonizes the cecum.

Induction of multiple matrix metalloproteinases in human dermal and synovial fibroblasts by Staphylococcus aureus: implications in the pathogenesis of septic arthritis and other soft tissue infections.

Infections of body tissue by Staphylococcus aureus are quickly followed by degradation of connective tissue. Patients with rheumatoid arthritis are more prone to S. aureus-mediated septic arthritis. Various types of collagen form the major structural matrix of different connective tissues of the body. These different collagens are degraded by specific matrix metalloproteinases (MMPs) produced by fibroblasts, other connective tissue cells, and inflammatory cells that are induced by interleukin-1 (IL-1) and tumor necrosis factor (TNF). To determine the host's contribution in the joint destruction of S. aureus-mediated septic arthritis, we analyzed the MMP expression profile in human dermal and synovial fibroblasts upon exposure to culture supernatant and whole cell lysates of S. aureus. Human dermal and synovial fibroblasts treated with cell lysate and filtered culture supernatants had significantly enhanced expression of MMP-1, MMP-2, MMP-3, MMP-7, MMP-10, and MMP-11 compared with the untreated controls (p < 0.05). In the S. aureus culture supernatant, the MMP induction activity was identified to be within the molecular-weight range of 30 to >50 kDa. The MMP expression profile was similar in fibroblasts exposed to a combination of IL-1/TNF. mRNA levels of several genes of the mitogen-activated protein kinase (MAPK) signal transduction pathway were significantly elevated in fibroblasts treated with S. aureus cell lysate and culture supernatant. Also, tyrosine phosphorylation was significantly higher in fibroblasts treated with S. aureus components. Tyrosine phosphorylation and MAPK gene expression patterns were similar in fibroblasts treated with a combination of IL-1/TNF and S. aureus. Mutants lacking staphylococcal accessory regulator (Sar) and accessory gene regulator (Agr), which cause significantly less severe septic arthritis in murine models, were able to induce expression of several MMP mRNA comparable with that of their isogenic parent strain but induced notably higher levels of tissue inhibitors of metalloproteinases (TIMPs). To our knowledge, this is the first report of induction of multiple MMP/TIMP expression from human dermal and synovial fibroblasts upon S. aureus treatment. We propose that host-derived MMPs contribute to the progressive joint destruction observed in S. aureus-mediated septic arthritis.

Trimethoprim-sulfamethoxazole associated rhabdomyolysis in a patient with AIDS: case report and review of the literature.

We report a case of rhabdomyolysis associated with the use of trimethoprim-sulfamethoxazole (TMP-SMX) in a newly diagnosed AIDS patient with presumed Pneumocystis jiroveci (formerly named Pneumocystis Carinii) pneumonia. The present case is significant because of the paucity of similar cases in the literature and the relative frequency with which TMP-SMX is used today.

High mortality in egg layers as a result of necrotic enteritis.

A new facility was designed to hold 1.8 million birds in 10 houses; chickens were placed in five of the houses, and the remaining five houses were under construction when this outbreak occurred. An increase in mortality was reported in five houses; however, mortality in house 7 was quite high. Well-fleshed birds were suddenly found dead without a significant drop in egg production. The middle and distal intestines were distended with gas, congested, thin walled, atonic, and bluish or pale in color with sloughed mucosa in some places. Necrotic enteritis was diagnosed as the cause of increased mortality. The ingesta in the crop occasionally contained flies. The 4-wk mortality in house 7 was 6.55% with a loss of 10,898 chickens. The 4-wk mortality rate in the other houses ranged from 0.54% to 1.98%. The houses affected with necrotic enteritis were treated for coccidiosis with amprolium because low numbers of the oocysts were present in the intestinal specimens of some of the chickens. Household bleach was added to the water at a dilution of one part bleach to 1040 parts water to control bacterial contamination. The fly (Musca domestica) population was out of control. Clostridium perfringens was isolated from the alcohol-washed macerated flies caught from houses 4 and 7. Dead flies were often seen in the feed troughs. The chickens may possibly have had C. perfringens infection as a result of consumption of dead flies or their secretions/excretions. The alcohol-washed, macerated, clarified fly extract from the affected houses caused death in 11 inoculated mice and paralysis in one mouse. Similarly, illness and mortality were present in four mice inoculated with clarified intestinal contents. The bacterium isolated on anaerobic culture was identified as C. perfringens by polymerase chain reaction. The disease was brought under control after straw was added and mixed in with the litter. As a result, the litter temperature increased, causing a decrease in the fly population. This study suggests that flies in the poultry houses acted as mechanical transmitters of C. perfringens and that the development of necrotic enteritis was by ingestion of bacteria present in the flies and their secretions/excretions.