The obligate intracellular bacterium Chlamydia trachomatis is the most common bacterial STD agent in the US. This bacterium has a unique biphasic developmental cycle in which the infectious elementary body (EB) infects a host mucosal epithelial cell and differentiates into the replicative form (the reticulate body or RB) within a modified vacuole called an inclusion. The RB later divides and develops back into an EB and is released, perpetuating the infectious cycle. When developing chlamydiae are exposed to unfavorable environmental conditions, they deviate from the normal developmental cycle into a non-infectious but viable state termed persistence. Previous data from our laboratory indicate that i) during C. trachomatis/HSV co-infection, the chlamydiae become persistent and ii) HSV gD interaction with host cell surface is sufficient to induce this response. During viral entry, HSV gD interacts with one of four host co-receptors, one of which is the host adhesion molecule nectin-1. Interestingly, Western blotting demonstrated that nectin-1 is significantly decreased in C. trachomatis-infected HeLa cells. Additional studies indicated that active C. trachomatis replication is required for nectin-1 down-regulation and nectin-1 is likely down-regulated post-translationally. CPAF, a chlamydia-secreted protease, is responsible for degrading several host proteins. Both in vivo experiments using CPAF-specific chemical inhibitors and cell-free cleavage assays using recombinant CPAF indicate that nectin-1 is degraded by CPAF in C. trachomatis-infected cells. Further studies suggest that nectin-1 is the most likely candidate involved in triggering HSV-induced chlamydial persistence. Co-infection experiments using nectin-1-specific HSV-1 mutants suggest that nectin-1 is, indeed, required for persistence induction. Additional studies in single co-receptor-expressing CHO cells demonstrate that, despite the fact that HSV-1 enters both HVEM- and nectin-1-expressing cells, viral co-infection reduces chlamydial infectivity only in the CHO-nectin-1 cell line. These data confirm that HSV/nectin-1 interaction is sufficient for chlamydial persistence induction. Although nectin-1 ligation is known to activate Cdc42, pull-down assays indicate that Cdc42 is not activated in co-infected HeLa cells. Taken together, these data suggest that: i) HSV gD-nectin-1 binding activates a novel host epithelial cell pathway that restricts chlamydial development and ii) the chlamydiae may degrade nectin-1 to evade this inhibitory host response.

Cryptococcus neoformans is an encapsulated yeast responsible for severe meningoencephalitis. The importance of epidemiological studies on cryptococcosis has increased since the beginning of the AIDS epidemic. C. neoformans exists in two varieties containing four serotypes, C. neoformans var. neoformans (serotypes A and D) and C. neoformans var. gattii (serotypes B and C). Locally C. neoformans var. neoformans has been associated with pigeon feces during those months having an average temperature of 64.2°F j(17.8°C) and above. Clinical and environmental isolates of C. neoformans obtained from regional hospitals and environmental samplings, respectively, have been grouped into their variety status utilizing canavanine-glycine-bromthymol blue agar. Polyclonal antisera against C. neoformans serotypes A, B, C and D were isolated from challenged rabbits. Serotyping C. neofromans isolates using the polyclonal antisera resulted in 57% (20 of 35) of the serotypes confirmed with a direct immunofluorescent assay utilizing a single monoclonal antibody (E1). Data from the immunofluorescence assay suggest all C. neoformans obtained from regional hospitals (26 of 26) and those isolated from the environment (9 of 9) belong to the A serotype group. These data have provided information leading to the origin of infection for cryptococcosis in our region, which may be beneficial to immunocompromised individuals.

Scrub typhus is a potentially fatal infection that threatens one billion persons in the Asia-Pacific region and is caused by the obligate intracellular bacterium, Orientia tsutsugamushi. How this organism facilitates its intracellular survival and pathogenesis is poorly understood. Intracellular bacterial pathogens utilize the Type 1 (T1SS) or Type 4 secretion system (T4SS) to translocate ankyrin repeat-containing proteins (Anks) into the host cell to modulate host cell processes. The O. tsutsugamushi genome encodes one of the largest known bacterial Ank libraries as well as Type 1 and Type 4 secretion systems (T1SS and T4SS), which are expressed during infection. In silico analyses of the Anks’ C-termini revealed that they possess characteristics of T1SS secretion signals. Escherichia coli expressing a functional T1SS was able to secrete chimeric hemolysin proteins bearing the C-termini of 19 of 20 O. tsutsugamushi Anks. In addition to infecting endothelial cells, O. tsutsugamushi infects professional phagocytes. To better understand why these innate immune cells are unable to eliminate O. tsutsugamushi, we addressed the activity of host NF-κB proinflammatory transcription factor. Screening of O. tsutsugamushi infected cells at an MOI of 1 revealed inhibition of NF-κB nuclear accumulation as early as 8 hours in HeLa and bone-marrow derived macrophage cells. When stimulating infected cells with TNF-α, IκBα degradation still occurs, however NF-κB dependent gene transcription remains downregulated. Immunofluorescence microscopic analysis of TNF-α treated cells ectopically expressing all O. tsutsugamushi Anks revealed that two nuclear trafficking Anks, Ank1 and Ank6, result in a significant decrease in NF-κB nuclear accumulation. Additionally, these Anks also significantly inhibited NF-κB dependent gene transcription. Co-immunoprecipitation experiments revealed that both Anks interact with importin-β1, exportin-1, and the p65 NF-κB subunit. Treating cells with importazole significantly reduces the nuclear accumulation of Ank1 and Ank6. Finally, treating infected cells or cells ectopically expressing Ank1 or Ank6 with leptomycin B resulted in restoration of NF-κB nuclear accumulation. With these data, we propose that O. tsutsugamushi secretes Ank1 and Ank6 to initially interact with importin-β1, which permits their nuclear entry where they then interact with NF-κB and subsequently exportin-1 to prevent NF-κB nuclear accumulation.

A newly discovered cysteine protease, Prp, has been shown to perform an essential, site-specific cleavage of ribosomal protein L27 in Staphylococcus aureus. In Firmicutes and related bacteria, ribosomal protein L27 is encoded with a conserved N-terminal extension that must be removed to expose residues critical for ribosome function. Uncleavable and pre-cleaved variants were unable to complement an L27 deletion in S. aureus, indicating that this N-terminal processing event is essential and likely plays an important regulatory role. The gene encoding the responsible protease (prp) has been shown to be essential, and is found in all organisms encoding the N-terminal extension of L27. Cleavage of L27 by Prp represents a new target for potential antibiotic therapy. In order to characterize this protease, Prp has been overexpressed and purified. Using an assay we have developed, based on cleavage of a fluorogenic peptide derived from the conserved L27 cleavage sequence, we have undertaken an analysis of the enzyme kinetics and substrate specificity for Prp cleavage and tested predictions made based on a structural model using active-site mutants.

Introdução: Em estudo prospectivo, os efeitos da gastroplastia redutora com reconstrução em Y de Roux sobre a flora bacteriana e produção de citoquinas nas câmaras gástricas proximal e excluída foram estudados. Métodos: pacientes bariátricos (n=37) foram submetidos à avaliação endoscópica em ambos reservatórios gástricos,7,3+-1,4 anos após a gastroplastia. Idade foi de 42,4+-9,9 anos (70,2% sexo feminino), IMC pré-operatório de 53,5+-10,6, e IMC atual de 32,6+-7,8kg/m2. TNFalfa e TGF-beta foram medidos pelo método ELISA em biópsias da mucosa gástrica., assim como cultura quantitativa da secreção gástrica, com pH gástrico e teste respiratório lactulose/hidrogênio.Resultados: Nenhum dos pacientes apresentou queixas sugestivas de supercrescimento bacteriano gastrointestinal. Todavia, contagens elevadas de bactérias e fungos foram identificadas nas duas câmaras, principalmente no estômago proximal. Gram-positivos representaram a maioria dos isolados. O pH foi neutro na câmara proximal, enquanto que também na câmara distal nem sempre conservou-se em níveis esperados. Conclusões: 1)Produção elevadas de TNF-alfa e TGF-beta, com a colonização de aeróbios, anaeróbios e fungos em ambas câmaras gástricas foram identificadas; 2)O pH gástrico como a contagem bacteriana foram maiores no estômago proximal funcionante; 3)Teste respiratório foi positivo para supercrescimento bacteriano em 40,5% dos pacientes,entretanto não foram identificadas manifestações clínicas de supercrescimento bacteriano gastrointestinal. / Background: In a prospective study, the effect of Roux-en-Y gastric bypass (RYGBP) on bacterial flora and cytokines production in the used (proximal pouch) and unused (large bypassed) gastric chamber was analysed. Methods: Bariatric subjects (n=37) were submitted to endoscopic examination of both gastric reservoirs, 7.3 ± 1.4 years after RYGBP. Age was 42.4 ± 9.9 years (70.2% females), preoperative BMI was 53.5 ± 10.6, and current BMI was 32.6 ± 7.8 kg/m2.TNF-alpha and TGF-beta were meausured by enzyme-linked immunosorbent assay (ELISA) from gastric mucosal biopsies. Quantitative culture of gastric secretion along with gastric pH and actulose/hydrogen breath test were also investigated.Results: None of the subjects displayed complaints suggestive of GI bacterial overgrowth. Elevated counts of bacteria and fungi were identified in both chambers, mostly in the proximal stomach. Gram-positives represented the majority of the isolates. Gastric pH was neutral in the proximal pouch, whereas the distal chamber mostly but not always onserved the expected acidity. Conclusions: 1)Increased TNF-alpha and TGFbeta production, as aerobes, anaerobes and fungi colonization of both gastric chambers was detected; 2) Gastric pH as well as bacterial count was higher in the functioning proximal stomach; 3) Breath test was positive for bacterial overgrowth in 40.5% of the subjects, however clinical manifestation of GI bacterial overgrowth were not demonstrated

Introdução: Em estudo prospectivo, os efeitos da gastroplastia redutora com reconstrução em Y de Roux sobre a flora bacteriana e produção de citoquinas nas câmaras gástricas proximal e excluída foram estudados. Métodos: pacientes bariátricos (n=37) foram submetidos à avaliação endoscópica em ambos reservatórios gástricos,7,3+-1,4 anos após a gastroplastia. Idade foi de 42,4+-9,9 anos (70,2% sexo feminino), IMC pré-operatório de 53,5+-10,6, e IMC atual de 32,6+-7,8kg/m2. TNFalfa e TGF-beta foram medidos pelo método ELISA em biópsias da mucosa gástrica., assim como cultura quantitativa da secreção gástrica, com pH gástrico e teste respiratório lactulose/hidrogênio.Resultados: Nenhum dos pacientes apresentou queixas sugestivas de supercrescimento bacteriano gastrointestinal. Todavia, contagens elevadas de bactérias e fungos foram identificadas nas duas câmaras, principalmente no estômago proximal. Gram-positivos representaram a maioria dos isolados. O pH foi neutro na câmara proximal, enquanto que também na câmara distal nem sempre conservou-se em níveis esperados. Conclusões: 1)Produção elevadas de TNF-alfa e TGF-beta, com a colonização de aeróbios, anaeróbios e fungos em ambas câmaras gástricas foram identificadas; 2)O pH gástrico como a contagem bacteriana foram maiores no estômago proximal funcionante; 3)Teste respiratório foi positivo para supercrescimento bacteriano em 40,5% dos pacientes,entretanto não foram identificadas manifestações clínicas de supercrescimento bacteriano gastrointestinal. / Background: In a prospective study, the effect of Roux-en-Y gastric bypass (RYGBP) on bacterial flora and cytokines production in the used (proximal pouch) and unused (large bypassed) gastric chamber was analysed. Methods: Bariatric subjects (n=37) were submitted to endoscopic examination of both gastric reservoirs, 7.3 ± 1.4 years after RYGBP. Age was 42.4 ± 9.9 years (70.2% females), preoperative BMI was 53.5 ± 10.6, and current BMI was 32.6 ± 7.8 kg/m2.TNF-alpha and TGF-beta were meausured by enzyme-linked immunosorbent assay (ELISA) from gastric mucosal biopsies. Quantitative culture of gastric secretion along with gastric pH and actulose/hydrogen breath test were also investigated.Results: None of the subjects displayed complaints suggestive of GI bacterial overgrowth. Elevated counts of bacteria and fungi were identified in both chambers, mostly in the proximal stomach. Gram-positives represented the majority of the isolates. Gastric pH was neutral in the proximal pouch, whereas the distal chamber mostly but not always onserved the expected acidity. Conclusions: 1)Increased TNF-alpha and TGFbeta production, as aerobes, anaerobes and fungi colonization of both gastric chambers was detected; 2) Gastric pH as well as bacterial count was higher in the functioning proximal stomach; 3) Breath test was positive for bacterial overgrowth in 40.5% of the subjects, however clinical manifestation of GI bacterial overgrowth were not demonstrated

Candida albicans is an opportunistic pathogen that is present in the normal flora in a majority of individuals. One key factor in C. albicans virulence is the ability to change its morphology from yeast to an elongated or hyphal form. The regulation of this morphogenesis relies in part upon quorum sensing (QS) molecules. C. albicans often exists as part of a mixed culture alongside other microbes and is influenced by their presence as well as the presence of QS molecules that they produce. In this study, a library of diploid homozygous transcriptional regulator knockout (TRKO) mutants were screened to identify strains capable of forming hyphae in the presence of Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. We identified three strains that showed increased hyphae development compared to wild type C. albicans. The strains identified had deletions of the transcriptional regulating genes Orf19.3928, Orf19.2842 (GZF3), and Orf19.3865 (RFX1). These strains were tested for alterations of filamentation in liquid media, and biofilm formation. All three strains showed increased rates of biofilm formation compared to the wild type. Orf19.3928 showed altered response to farnesol, a marked in biofilm formation and no inhibition of filamentation when farnesol was present in liquid media. The GZF3 deletion strain showed enhanced filamentation with all three bacterial species while the RFX1 deletion strain showed increased filamentation only with E. coli and S. aureus. In spent media, GZF3 showed slight increases in filamentation in E. coli and S. aureus while RFX1 had moderate increases in filamentation in E. coli and S. aureus and slight increases with P. aeruginosa.

Sepsis is the most frequent cause of mortality in most intensive care units. Cardiovascular dysfunction is a major complication associated with sepsis, with high mortality rates up to 70%. Currently, there is no effective treatment approach for sepsis. The integrity of the endothelium is fundamental for the homeostasis of the cardiovascular system. Sepsis induces endothelial cell injury which is the key factor for multiple organ failure. The increased expression of adhesion molecules and chemokines in endothelial cell promotes leukocytes infiltration into the tissue. The loss of tight junction proteins and increased permeability of the endothelial cells will provoke tissue hypoxia and subsequent organ failure. Therefore, preservation of endothelial function is a critical approach for improving sepsis-induced outcome. Here, we showed that endothelial specific protein HSPA12B plays a critical role in the preservation of cardiovascular function in polymicrobial sepsis. HSPA12B is the newest member of HSP70 family which predominantly expresses in endothelial cells. We observed that HSPA12B deficiency (HSPA12B-/-) exaggerated polymicrobial sepsis-induced endothelial dysfunction, leading to worse cardiac dysfunction. HSPA12B-/- significantly increases the expression of adhesion molecules, decreases tight junction protein levels and enhances vascular permeability. HSPA12B-/- alsomarkedly promotes the infiltration of inflammatory cells into the myocardium and inflammatory cytokine production. We investigated the cardioprotective mechanisms of HSPA12B in sepsis induced cardiovascular dysfunction. Exosomes play a critical role in intercellular communication. Exosome is a natural vehicle of microRNAs. We found that exosomes isolated from HSPA12B-/- septic mice induced more expression of adhesion molecules in endothelial cells and inflammation in macrophages. Interestingly, the levels of miR-126 in serum exosomes isolated from HSPA12B-/- septic mice were significantly lowers than in WT septic mice. Importantly, delivery of miR-126 carried exosomes significantly improved cardiac function, suppressed the expression of adhesion molecules, reduced immune cell infiltration in the myocardium, and improved vascular permeability in HSPA12B-/- septic mice. The data suggests that HSPA12B is essential for endothelial function in sepsis and that miR-126 containing exosomes plays a critical role in cardiovascular-protective mechanisms of endothelial HSPA12B in polymicrobial sepsis.

Lyme disease, caused by the bite of a deer tick infected with Borrelia burdorferi, has been increasing in distribution and prevalence annually throughout Maine. Worker’s compensation claims for Lyme disease have also been increasing steadily since the initial claim made in 1999. This research reviewed Maine worker’s compensation claims for Lyme disease from 1999-2011 to determine trends in state distribution and occupation type. Descriptive statistics were calculated to analyze different distributions of occupational Lyme disease. Occupations with the highest distribution of Lyme disease claims were those requiring workers to spend the majority of their time outdoors. A clear trend of claim distribution was seen, which mirrored that of the State of Maine Lyme disease case surveillance data. With the apparent increase in worker’s compensation claims due to Lyme disease and an increased geographic distribution annually, additional prevention and education efforts should be focused toward the higher risk occupations.

Hospital-acquired infections (HAI) are not uncommon in healthcare facilities. They are usually prevented by sanitation techniques and by maintaining a high standard of care. Catheter-associated urinary tract infections (CAUTI) make up a large percentage of hospital-acquired infections and are often the most preventable type of HAI. Patterns in infection rate could provide new ideas on prevention techniques, which might further reduce infection rate, saving lives and cutting costs. CAUTI infection rate was measured from January KJIY to September KJIL and was differentiated based on hospital ward as well as month and season. Overall, ICU units tended to have a higher CAUTI infection rate than ward units, particularly in January, February, April, and May. The CAUTI infection rate was highest in the ICU units during spring and May, and lowest during fall and October. In the ward units, the CAUTI infection rate was highest during summer and March, and lowest during winter and February.