Heavy Bacterial Load Research Articles

Porcine extraintestinal pathogenic Escherichia coli delivers two serine protease autotransporters coordinately optimizing the bloodstream infection.

Extraintestinal pathogenic Escherichia coli (ExPEC) is one of the leading causes of bloodstream infections in a broad spectrum of birds and mammals, thus poses a great threat to public health, while its underlying mechanism causing sepsis is not fully understood. Here we reported a high virulent ExPEC strain PU-1, which has a robust ability to colonize within host bloodstream, while induced a low level of leukocytic activation. Two serine protease autotransporters of Enterobacteriaceae (SPATEs), VatPU-1 and TshPU-1, were found to play critical roles for the urgent blood infection of strain PU-1. Although the Vat and Tsh homologues have been identified as virulence factors of ExPEC, their contributions to bloodstream infection are still unclear. In this study, VatPU-1 and TshPU-1 were verified to interact with the hemoglobin (a well-known mucin-like glycoprotein in red blood cell), degrade the mucins of host respiratory tract, and cleave the CD43 (a major cell surface component sharing similar O-glycosylated modifications with other glycoprotein expressed on leukocytes), suggesting that these two SPATEs have the common activity to cleave a broad array of mucin-like O-glycoproteins. These cleavages significantly impaired the chemotaxis and transmigration of leukocytes, and then inhibited the activation of diverse immune responses coordinately, especially downregulated the leukocytic and inflammatory activation during bloodstream infection, thus might mediate the evasion of ExPEC from immune clearance of blood leukocytes. Taken together, these two SPATEs play critical roles to cause a heavy bacterial load within bloodstream via immunomodulation of leukocytes, which provides a more comprehensive understanding how ExPEC colonize within host bloodstream and cause severe sepsis.

Green nanotechnology for controlling bacterial load and heavy metal accumulation in Nile tilapia fish using biological selenium nanoparticles biosynthesized by Bacillus subtilis AS12.

Heavy metal accumulation and pathogenic bacteria cause adverse effects on aquaculture. The active surface of selenium (Se) nanoparticles can mitigate these effects. The present study used Se-resistant Bacillus subtilis AS12 to fabricate biological Se nanoparticles (Bio-SeNPs). The double-edged Bio-SeNPs were tested for their ability to reduce the harmful effects of heavy metals and bacterial load in Nile tilapia (Oreochromis niloticus) and their respective influences on fish growth, behavior, and health. The Bio-SeNPs have a spherical shape with an average size of 77 nm and high flavonoids and phenolic content (0.7 and 1.9 g g-1 quercetin and gallic acid equivalents, respectively), resulting in considerable antioxidant and antibacterial activity. The Bio-SeNPs (3-5 μg ml-1) in the current study resolved two serious issues facing the aquaculture industry, firstly, the population of pathogenic bacteria, especially Aeromonas hydrophilia, which was reduced by 28-45% in fish organs. Secondly, heavy metals (Cd and Hg) at two levels (1 and 2 μg ml-1) were reduced by 50-87% and 57-73% in response to Bio-SeNPs (3-5 μg ml-1). Thus, liver function parameters were reduced, and inner immunity was enhanced. The application of Bio-SeNPs (3-5 μg ml-1) improved fish gut health, growth, and behavior, resulting in fish higher weight gain by 36-52% and a 40% specific growth rate, compared to controls. Furthermore, feeding and arousal times increased by 20-22% and 28-53%, respectively, while aggression time decreased by 78% compared to the control by the same treatment. In conclusion, Bio-SeNPs can mitigate the accumulation of heavy metals and reduce the bacterial load in a concentration-dependent manner, either in the fish media or fish organs.

Evaluation of Total Coliform Counts in Non-Fermented and Fermented Cow Milk Products (Kindirmo, Mai-Shanu and Nono) in Zaria Metropolis, Nigeria

Testing for coliforms has a long history in dairy production, and has helped to identify the unsanitary condition of unpasteurized and pasteurized milk products. The study was performed to evaluate the level of coliform bacterial contamination in raw cow milk and milk products (kindirmo, mai-shanu, and nono). A total of 426 samples comprising 106 raw milk, 106 kindirmo, 106 mai-shanu and 108 nono were obtained from four selected Fulani herds (Damari, Marwa, Tudun-Muntsira, and Wuciciri) and four milk markets (Kasuwan-Mata, Kwangila, Samaru and Tudun-Wada) in Zaria Metropolis, all samples were tested using the bacteriological method. Coliform counts were analyzed using the one-way analysis of variance (ANOVA) using Tukey package and recorded as mean coliform counts (CFU/ML). The overall mean coliform counts for the milk products (raw milk, kindirmo, mai-shanu, and nono) were 98.88 ± 7.68 x 108 CFU/ML, 60.19 ± 5.49 x 108 CFU/ML, 60.36 ± 5.50 x 108 CFU/ML and 73.5 ± 7.09 x 108 CFU/ML respectively. The mean coliform counts for raw milk were significantly different (p ≤ 0.05) from the three products (kindirmo, mai-shanu and nono). The study revealed heavy coliform bacterial load, ranging between 60.19 ± 5.49 x 108 CFU/ML and 98.88 ± 7.68 x 108 CFU/ML. This study calls for educating farmers and milk retailers at different levels level of production on the hygienic way of handling milk along the value chain to minimize unnecessary contamination of milk and milk products which can be of public health significance.

Therapeutic potential of silver nanoparticle-based dressing in the healing process

Introduction: The skin covers the entire surface of the human body, and is considered its largest organ. The resistance of bacteria to antibiotics represents a growing concern in wound infections, this is evidenced by the fact that wounds associated with a heavy bacterial load often present healing failures, increasing healthcare costs for the patient and healing time. Objective: To evidence through national and international literature the therapeutic potential of silver nanoparticle-based dressings in the healing process. Methodology: This is a literature review of a dissertative and explanatory nature. To theoretically support this review, the Brazilian Digital Library of Theses and Dissertations (BDTD) and the Nursing Databases (BDENF) were used. The search period was from February to April 2022, with temporal delimitation from 2017 to 2022, because these were the years that most studies on the topic of interest were obtained. The Boolean searchers (AND and OR) were used: ¬ "Nanoparticle-based dressing OR "Pressure injury" AND "Nanoprene therapy" AND "Multiprofessional team" in BDENF and BDTD, interrelated with the Boolean operators AND and OR. This study included original articles, available in full, case studies, clinical studies, randomized studies, theses and dissertations on the topic in question, published from 2016 to 2022, in English and Portuguese. As exclusion criteria, it was decided not to use articles that were not adjusted to the object of study, which ran away from the theme proposed by the authors, those that were duplicated in electronic databases, incomplete texts, unavailable in full, literature reviews, guides, technical manuals and letters to the reader. A total of 211 articles were found in the BDTD and 17 in the BDENF database, totaling 228 studies found. Of these, after applying the inclusion and exclusion criteria, 211 were excluded and 17 studies were selected because they met the study objective. Results: The AgNP-based dressing, presents great potential in pharmaceutical, therapeutic and biomedical applications, and can be applied in the composition of topical products such as ointments, gels and adhesives.Conclusion: Dressings based on silver nanoparticles (AgNP) are being widely used in biomedical sciences, being relevant to circumvent bacterial resistance to antibiotics, improving the quality of life of affected patients and consequently reducing hospital costs.

Development of Gluten-Free Cupcakes Enriched with Almond, Flaxseed, and Chickpea Flours

Background. The mixing of cereals and legumes with nuts and seeds can produce various products that can be optimal for consumption with respect to their nutritional density. The use of legumes in gluten-free foods is becoming very prominent with increase in advancement in food engineering and technology. This study was aimed to develop a gluten-free product (cupcake) enriched with chick pea flour, almonds, and flaxseeds for celiac disease patients. Materials and Methods. The procured raw material including almonds, chickpea flour, and flaxseeds was mixed in appropriate amounts, and cupcakes were formulated following a specified recipe. The cupcakes were divided in five groups based on their recipe. First one was wheat based; 2nd one was corn and rice based; and next 3 were chickpea, almond, and flaxseed based, respectively. The cupcakes were checked for their proximate analysis parameters (carbohydrate, protein, and nitrogen-free extract), gluten and heavy metals (lead, chromium, and arsenic), bacterial load (E. coli, total coliforms, salmonella, yeast, and molds), fatty acid, texture parameters (firmness, cohesiveness, gumminess, and chewiness), and physical parameters (weight, height, volume, and specific volume). All these parameters were compared with wheat-based cupcakes to assess the product’s quality. Results. The volume of intervention cupcakes was a bit low compared to wheat/rice-based cupcakes but the specific volume was comparable. In texture analysis, firmness, gumminess, and chewiness were enhanced in intervention cupcakes compared to control but cohesiveness was comparable also. The carbohydrate contents were significantly lower in intervention cupcakes 22–30% compared to control cupcakes. Protein, fiber, and fat contents were significantly higher 11–14, 8–10, and 40%, respectively, with improvement (2-3 folds) in calcium, zinc, and iron contents in intervention cupcakes. All the safety parameters including heavy metals and bacterial and fungal load were found normal. The sensory attributes like size and color were found to be less acceptable but odor and taste were comparatively high in formulated products. Conclusion. The use of chickpeas, almonds, and flaxseeds in high concentration was first-time used to formulate a recipe of gluten-free cupcake. These cupcakes were more nutritious compared to available conventional recipes. Apparently, no health hazard was found in these cupcakes. Some sensory characteristics of cupcakes were slightly lower and comparable to wheat/rice-based cupcakes.

Chronic wounds in Sierra Leone: Searching for Buruli ulcer, a NTD caused by Mycobacterium ulcerans, at Masanga Hospital.

Chronic wounds pose a significant healthcare burden in low- and middle-income countries. Buruli ulcer (BU), caused by Mycobacterium ulcerans infection, causes wounds with high morbidity and financial burden. Although highly endemic in West and Central Africa, the presence of BU in Sierra Leone is not well described. This study aimed to confirm or exclude BU in suspected cases of chronic wounds presenting to Masanga Hospital, Sierra Leone. Demographics, baseline clinical data, and quality of life scores were collected from patients with wounds suspected to be BU. Wound tissue samples were acquired and transported to the Swiss Tropical and Public Health Institute, Switzerland, for analysis to detect Mycobacterium ulcerans using qPCR, microscopic smear examination, and histopathology, as per World Health Organization (WHO) recommendations. Twenty-one participants with wounds suspected to be BU were enrolled over 4-weeks (Feb-March 2019). Participants were predominantly young working males (62% male, 38% female, mean 35yrs, 90% employed in an occupation or as a student) with large, single, ulcerating wounds (mean diameter 9.4cm, 86% single wound) exclusively of the lower limbs (60% foot, 40% lower leg) present for a mean 15 months. The majority reported frequent exposure to water outdoors (76%). Self-reports of over-the-counter antibiotic use prior to presentation was high (81%), as was history of trauma (38%) and surgical interventions prior to enrolment (48%). Regarding laboratory investigation, all samples were negative for BU by microscopy, histopathology, and qPCR. Histopathology analysis revealed heavy bacterial load in many of the samples. The study had excellent participant recruitment, however follow-up proved difficult. BU was not confirmed as a cause of chronic ulceration in our cohort of suspected cases, as judged by laboratory analysis according to WHO standards. This does not exclude the presence of BU in the region, and the definitive cause of these treatment-resistance chronic wounds is uncertain.

ASSESSMENT OF BACTERIAL CONTAMINATION LEVELS ON THE SURFACE OF THE BOVINE CARCASSES AT SLAUGHTERHOUSES OF BARISHAL CITY IN BANGLADESH

Background: Meat industries in developing countries including Bangladesh are found to be challenged by severe hygienic and sanitation problems which are associated with heavy bacterial load on the different sites of carcasses and meat. Objectives: The major objectives of this study were to determine the bacterial load at the different risk sites of bovine carcasses and identification of pathogenic bacteria as well as to assess the associated hygienic and sanitation practices with public health significance of the isolated bacteria. Materials and Methods: The study on bacterial load of bovine carcasses was conducted on 200 swab samples of different risk sites of 20 bovine carcasses in the different slaughterhouses of Barishal City Corporation during the period from April to October 2017. The aseptically collected swab samples from different sites of bovine carcasses were processed and analyzed individually by standard bacteriological procedures for Total viable count (TVC), Total coliform count (TCC), Total Staphylococcus count (TSC) and Total Salmonella count (TSAC) and the bacterial species were identified by the conventional aerobic cultural, morphological and biochemical tests. The hygienic status and practices of slaughterhouses and workers were evaluated through a structured questionnaire survey and also a visual inspection. Results: Staphylococcus aureus (78.5%), Salmonella spp. (64.5%) and Escherichia coli (64.0%) were found widely prevalent bacteria on the surface of freshly slaughtered bovine carcasses. The mean TVC of bacteria at pre-and post-washing of the different risk sites of carcasses including neck, shoulder, rump and their used knife and workers’ hand was calculated and highest one was recorded for neck at both pre (8.17 ± 1.22) and post (8.41 ± 0.92) washings. These TVC were found higher compared to standards set by WHO. The TSC was found highest at shoulder site at both pre (7.26 ± 0.94) and post (7.43 ± 1.02) washing, whereas the neck site was found highest contaminated with E. coli (6.69 ± 1.06 and 6.87 ± 1.04) and Salmonella spp.(5.73 ± 1.05 and 6.07 ± 0.92), respectively. The questionnaire survey and visual inspection of slaughter houses revealed that none of the slaughterhouse workers received any training on slaughterhouses management and hygiene, not used any head and hair covering, protective clothes and hand gloves whereas only 25.33% workers washed their hands and 34.67% used clean water at slaughterhouses during processing of carcasses and meat. Conclusions: The slaughtering of the animals on the ground and then skinning and evisceration in the same place under poor hygienic conditions are the major risk factors for heavy bacterial contamination of carcasses which has been recognized as a threat to food safety and consumers health to foodborne illness. Therefore, it requires a serious attention from all relevant authorities to apply and maintain the basic hygienic slaughterhouse practices to prevent the bacterial contamination of carcasses to prevent food borne illness. However, these data should serve as a baseline for future comparisons in measuring the bacteriological status of beef carcasses in other districts and further research works.

Remediation of Some Heavy Metals, Radionuclides and Bacterial Load of Medically Acclaimed Edible Kaolin

Remediation of Some Heavy Metals, Radionuclides and Bacterial Load of Medically Acclaimed Edible Kaolin

Host responses and bacterial colonization following inoculation of Pasteurella multocida P52 strain into unvaccinated and aluminum hydroxide gel hemorrhagic septicemia vaccinated mice

Hemorrhagic septicemia is a highly infectious and contagious disease caused by Pasteurella multocida serogroup B:2 in tropical Asian and African countries. The acute inflammatory responses induced by Pasteurella multocida are the main cause of death in hemorrhagic septicemia. Therefore, present study was undertaken to examine the blood cytokine expression profiles (TNF-α, IL-1β, and IL-6), bacterial colonization and histopathological changes of intraperitoneally and subcutaneously challenged vaccinated and unvaccinated mice with 102 CFU of P. multocida P52. The observations were made at 6, 12, 18, 24 h and 48 h intervals. Real-time PCR based blood cytokine profiles (TNF-α, IL-1β, and IL-6) measurement revealed a significantly higher amount of pro-inflammatory cytokines expression in the unvaccinated challenged group of mice than the vaccinated challenged group. There was heavy bacterial load in all organs of mice viz. trachea, lung, spleen, within 6 h of challenge in both vaccinated and unvaccinated group of mice, but bacterial load increased in the unvaccinated challenged group of mice with respect to time whereas the load were constant in the vaccinated challenged group. Histopathological changes were mild in the vaccinated challenged group of mice in comparison to the unvaccinated challenged group. There was no significant difference in the bacterial load, histopathological changes and cytokines expression when challenged through different routes.

Adjuvant role of Pseudomonas flagellin for Acinetobacter baumannii biofilm associated protein.

AIMTo study immunogenicity of Pseudomonas N terminal flagellin as an adjuvant for Acinetobacter baumannii (A. baumannii) biofilm associated protein (Bap).METHODSThe N terminal flagellin gene was amplified. The pET28a (+) and polymerase chain reaction products were digested with HindIII and EcoR I. The ligation of N terminal flagellin into pET28a (‏+) was performed using T4 DNA ligase and was then transformed into Escherichia coli BL21 (DE3) as a suitable expression host. pET28a (‏+) vector harboring a conserved region of Bap from our previous work was used. The recombinant proteins were expressed, analyzed by SDS-PAGE method and was purified by affinity chromatography with His-Tag residues followed by confirmation with western blotting. Mice were immunized with recombinant N terminal flagellin and Bap subunits. The immunized animals were intranasally (i.n) challenged with A. baumannii and Pseudomonas aeruginosa (P. aeruginosa).RESULTSThe flagellin enhanced the immunogenicity of Bap causing an increase in specific IgG titers in serum (P < 0.001). Internal organs, i.e., liver, lung and spleen of the Bap-Flagellin immunized group challenged with A. baumannii showed significantly lower bacterial load compared to the control group. The bacterial loads were studied in internal organs. A. baumannii infected immunized animals with Bap-Flagellin exhibited internal organs with minor bacterial load while P. aeruginosa PAO1 infected group showed heavy bacterial load of (4.3 ± 0.12) × 106, (1.1 ± 0.01) × 106 and (2.2 ± 0.22) × 106 per gram of lungs, liver and spleen respectively. Bacterial loads were detected per gram of lungs, liver and spleen of the mice group immunized with Bap were (1.2 ± 0.06) × 107, (11.1 ± 0.041) × 105 and (3.6 ± 0.42) × 106 respectively. In vivo neutralization assay indicated that all experimental mice groups, except for Flagellin administered group was significantly (P < 0.05) protected against A. baumannii.CONCLUSIONThese results demonstrate that P. aeruginosa Flagellin as an adjuvant for BapA. baumannii could be a useful model to evaluate new vaccine against A. baumannii.

Hand Hygiene in Emergency Medical Services

Background. Hospital-acquired infections (HAIs) affect millions of patients annually (World Health Organization. Guidelines on Hand Hygiene in Healthcare. Geneva: WHO Press; 2009). Hand hygiene compliance of clinical staff has been identified by numerous studies as a major contributing factor to HAIs around the world. Infection control and hand hygiene in the prehospital environment can also contribute to patient harm and spread of infections. Emergency medical services (EMS) practitioners are not monitored as closely as hospital personnel in terms of hand hygiene training and compliance. Their ever-changing work environment is less favorable to traditional hospital-based aseptic techniques and education. Methods. This study aimed to determine the current state of hand hygiene practices among EMS providers and to provide recommendations for improving practices in the emergency health services environment. This study was a prospective, observational prevalence study and survey, conducted over a 2-month period. We selected participants from visits to three selected hospital emergency departments in the mid-Atlantic region. There were two data components to the study: a participant survey and hand swabs for pathogenic cultures. Results. This study recruited a total sample of 62 participants. Overall, the study revealed that a significant number of EMS providers (77%) have a heavy bacterial load on their hands after patient care. All levels of providers had a similar distribution of bacterial load. Survey results revealed that few providers perform hand hygiene before (34%) or in between patients (24%), as recommended by the Centers for Disease Control and Prevention guidelines. Conclusion. This study demonstrates that EMS providers are potential vectors of microorganisms if proper hand hygiene is not performed properly. Since EMS providers treat a variety of patients and operate in a variety of environments, providers may be exposed to potentially pathogenic organisms, serving as vectors for the exposure of their patients to these same organisms. Proper application of accepted standards for hand hygiene can help reduce the presence of microbes on provider hands and subsequent transmission to patients and the environment.

Occurrence and Virulence Characteristics of Aeromonas Species in Meat, Milk and Fish in India

AbstractAeromonas‐induced gastroenteritis is common in India. The incidence of Aeromonas in meat, milk and fish in Kolkata, India and their enterotoxic potentiality have been evaluated here. Aeromonas contamination was detected in all or most of the meat and fish with average load of 1.1 × 102, 3.5 × 103, 1.1 × 103, 2.1 × 103 and 1.6 × 104 cfu/g of red meats, chicken, Indian major carps, tilapia and shrimp, respectively; the levels were at least one order higher on fish skin and meat surface. Aeromonas was also detected in milk and ready‐to‐eat foods. About 59% of the isolates were β‐hemolytic, and 66–92% of them produced phospholipase, caseinase and enterotoxicity. Fish and shrimp isolates produced significantly higher levels of gelatinase (102.73–120.6 U/mL), hemolysin (causing &gt;80% erythrocyte lysis) and enteric fluid accumulation (0.86–0.89 mL/cm ileum length) compared with those from meat and milk indicating their serious pathogenic potentiality. Phenotypically, 43.2, 12.2 and 12.2% of β‐hemolytic strains were identified as recognized human pathogenic species, viz. Aeromonas hydrophila, Aeromonas caviae and Aeromonas veronii bv. sobria, respectively, which also expressed higher levels of virulence factors than other Aeromonas species detected. The ubiquitous presence of enterotoxigenic Aeromonas in different raw as well as ready‐to‐eat foods poses serious threat to human health.Practical ApplicationsUbiquitous presence of enterotoxigenic Aeromonas hydrophila, Aeromonas caviae and Aeromonas veronii bv. sobria in raw and ready‐to‐eat meat, milk and fish poses a serious human health risk in Indian subcontinent. Heavy bacterial load, combined with higher expression of virulence factors by the isolates, makes fish and shellfish as the most potential sources of Aeromonas infection. Different Aeromonas spp. differed in quantitative expression of different virulence factors. Qualitative and quantitative expression studies showed low positive correlations among gelatinase, hemolysin and ileal enterotoxicity, suggesting requirement of studying multiple virulence factors for identifying the virulent strains. A higher distribution of the bacterium on meat or fish surface and in unhygienically processed or stored food items indicates that adoption of standard practices of cleaning and sanitation would substantially improve safety of food products.

Mouse model of haemorrhagic septicaemia: dissemination and multiplication of Pasteurella multocida B:2 in vital organs after intranasal and subcutaneous challenge in mice

Haemorrhagic septicaemia (HS) is an endemic disease of bovines, occurring in most tropical regions of Asia and Africa. In the present study, the suitability of using mice to study pathogenesis of HS was assessed using mortality, mean death time and bacterial multiplication in vital organs after infection with live P multocida. Mice were infected with 10(5), 10(3) and 10(1)cfu of P. multocida B:2 via intranasal and subcutaneous routes along with control groups. Bacterial multiplication in lung, liver and spleen of mice were determined at 24 h interval after intranasal and subcutaneous challenge. More than 80 % of challenged mice died within 48 h of inoculation, irrespective of the dose and route of inoculation. A heavy bacterial load (up to 10(8)cfu) was observed in lung, liver and spleen of mice titrated at 24 h and following death of mice. Results of the present study indicate that even ten bacteria are enough to cause mortality in mice and the organism multiplies rapidly in respiratory epithelium and disseminated to other vital organs viz liver and spleen suggesting the important role of mouse model in investigating the pathogenesis and challenge studies during vaccine development.

Mouse Strain-Dependent Differences in Estrogen Sensitivity During Vaginal Candidiasis

The animal models available for studying the immune response to genital tract infection require induction of a pseudo estrous state, usually achieved by administration of 17-β-estradiol. In our experimental model of vaginal candidiasis, under pseudo estrus, different strains of mice were used. We observed major differences in the clearance of Candida albicans infection among the different strains, ascribable to differing susceptibility to estradiol treatment. In the early phase of infection CD1, BALB/c, C57BL/6 albino and C57BL/6 mice were colonized to similar levels, while in the late phase of infection, BALB/c mice, which are considered genetically resistant to C. albicans infection, exhibited greater susceptibility to vaginal candidiasis than CD1 and C57BL/6 albino strains of mice. This was because estradiol induced "per se" enlarged and fluid-filled uteri, more pronounced in infected mice and consistently more evident in BALB/c and C57BL/6 mice than in CD1 mice. Unlike CD1, BALB/c and C57BL/6 mice showed a heavy fungal colonization of the uterus, even though C57BL/6 mice apparently cleared C. albicans from the vagina. The presence of C. albicans in the vagina and uterus was accompanied by a heavy bacterial load. Collectively these observations prompted us to carry out a careful analysis of estradiol effects in a mouse model of vaginal infection.

Immunization of adult dairy cattle with a new heat-killed vaccine is associated with longer productive life prior to cows being sent to slaughter with suspected paratuberculosis

The objective of this study was to evaluate the efficacy of a new heat-killed Mycobacterium avium ssp. paratuberculosis (MAP) vaccine for control of premature culling in tuberculosis-free dairy cattle. Feces and gastrointestinal tissues were collected from 50 vaccinated cows and 38 nonvaccinated cows at slaughter and analyzed by bacteriological culture and histopathology. Vaccination was associated with a significant reduction of the frequency of vaccinated animals with MAP in feces and gut tissues compared with the nonvaccinated animals. In addition, the frequency of vaccinated animals with heavy bacterial load in gut tissues was 40% lower than the frequency of the nonvaccinated animals with the same MAP load. The peak age of paratuberculosis-associated culling was from 4.5 to 5 yr old (21%) in the vaccinated animals and from 3 to 4.5 yr old (60%) in the nonvaccinated animals. The vaccinated and nonvaccinated animals with suspected paratuberculosis were culled at an average age of 4.7 and 3.7 yr old, respectively. Therefore, a significant increase in the productive life of the vaccinated animals sent to slaughter with suspected paratuberculosis was observed. In addition, our analysis revealed a positive effect of the vaccine on the carcass weights of the animals with severe histopathological lesions at slaughter compared with the nonvaccinated animals. In summary, our findings suggest a therapeutic effect of the vaccine and a significant attenuation of pre-existing infection in cows naturally infected with paratuberculosis that were adults at the time of vaccination.

Investigation of a community outbreak of typhoid fever associated with drinking water

BackgroundThis report is about the investigation of an outbreak of typhoid fever claimed three human lives and left more than 300 people suffered within one week. The aim of this report is to draw the attention of global health community towards the areas that are still far from basic human essentialities.MethodsA total of 250 suspected cases of typhoid fever were interviewed, out of which 100 were selected for sample collection on the basis of criteria included temperature > 38°C since the onset of outbreak, abdominal discomfort, diarrhea, vomiting and weakness. Food and water samples were also collected and analyzed microbiologically.ResultsInhabitants of village lived in poor and unhygienic conditions with no proper water supply or sewage disposal facilities and other basic necessities of life. They consumed water from a nearby well which was the only available source of drinking water. Epidemiological evidences revealed the gross contamination of well with dead and decaying animal bodies, their fecal material and garbage. Microbiological analysis of household and well water samples revealed the presence of heavy bacterial load with an average total aerobic count 106-109 CFU/ml. A number of Gram positive and Gram negative bacteria including Escherichia coli, Klebsiella, Bacillus species, Staphylococcus species, Enterobacter species, and Pseudomonas aeruginosa were isolated. Lab investigations confirmed the presence of multidrug resistant strain of Salmonella enterica serovar Typhi in 100% well water, 65% household water samples and 2% food items. 22% of clinical stool samples were tested positive with Salmonella enterica serover TyphiConclusionsThis study indicated the possible involvement of well water in outbreaks. In order to avoid such outbreaks in future, we contacted the local health authorities and urged them to immediately make arrangements for safe drinking water supply.

Isolation ofMycobacterium aviumsubsp.paratuberculosisfrom Muscle Tissue of Naturally Infected Cattle

Johne's disease or paratuberculosis is a chronic granulomatous inflammation of the small intestine of ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). Recent studies suggest an association between MAP and Crohn's disease in humans. MAP can become widely distributed within the tissues of infected animals, and meat may be a possible route of exposure of MAP to humans. In this study, 47 dairy and beef cattle were examined for the occurrence of viable MAP in diaphragm muscle. At the slaughterhouse, gut tissues, diaphragm muscle, blood, and feces of the 47 animals were collected for bacteriological culture, as well as gut samples for histopathological analysis. MAP was detected by bacteriological culture and conventional and real-time IS900 polymerase chain reaction in the diaphragm muscle of six infected cattle at slaughter (13%). The six animals showing evidence of MAP in diaphragm muscle had diffuse lesions and severe granulomatous inflammation in ileocecal lymph nodes, jejunal lymph nodes, ileocecal valve, and ileum. All six had heavy bacterial load in mesenteric lymph nodes, ileocecal valve, ileum, and jejunum, and four showed clinical signs of paratuberculosis. Two animals did not show clinical signs but had viable MAP in intestinal tissues and in diaphragm muscle as well. MAP was found in blood of only one of the six animals showing evidence of MAP in diaphragm muscle and in feces of three of them. In general, there was a positive association between enteric lesion severity, clinical signs of paratuberculosis, heavy bacterial load in intestinal tissues, fecal shedding of MAP, and the presence of disseminated MAP infection in diaphragm muscle. The results of this study demonstrated that MAP can be detected and cultured from muscle of MAP-infected cattle destined for human consumption and suggest a possible risk of exposure of humans to MAP via contaminated meat.

Paneth cells directly sense gut commensals and maintain homeostasis at the intestinal host-microbial interface

The intestinal epithelium is in direct contact with a vast microbiota, yet little is known about how epithelial cells defend the host against the heavy bacterial load. To address this question we studied Paneth cells, a key small intestinal epithelial lineage. We found that Paneth cells directly sense enteric bacteria through cell-autonomous MyD88-dependent toll-like receptor (TLR) activation, triggering expression of multiple antimicrobial factors. Paneth cells were essential for controlling intestinal barrier penetration by commensal and pathogenic bacteria. Furthermore, Paneth cell-intrinsic MyD88 signaling limited bacterial penetration of host tissues, revealing a role for epithelial MyD88 in maintaining intestinal homeostasis. Our findings establish that gut epithelia actively sense enteric bacteria and play an essential role in maintaining host-microbial homeostasis at the mucosal interface.

Future directions with daptomycin

Daptomycin is the first new natural-product antibiotic launched in a generation. It was licensed first for skin and soft tissue infections (SSTIs) and, more recently, for staphylococcal bacteraemia and endocarditis. Further clinical trials are in progress, some investigating performance in subsets of SSTIs while others, more interestingly, are evaluating efficacy in enterococcal endocarditis and neutropenic fevers--settings where the compound's bactericidal activity is potentially advantageous. There is a need for further trials in bone and joint infections. On the negative side, there are several reports of mutational resistance emerging during the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections, mostly in settings with a heavy bacterial load, and there is a need to determine whether higher dosages or combination regimens will reduce this risk. A few patients have already been treated with doses of up to 12 mg/kg. Lastly, daptomycin is entering a market increasingly crowded with new anti-Gram-positive agents. More work is required to establish those settings where daptomycin and other new compounds offer real advantages over established glycopeptides and over each other. There is presently a paradox whereby vancomycin is agreed to be less than ideal, with outcomes impaired against MRSA with modestly raised MICs, but where new agents have yet to demonstrate unequivocal superiority.

Attenuated Yersinia enterocolitica mutant strains exhibit differential virulence in cytokine-deficient mice: implications for the development of novel live carrier vaccines.

Yersinia enterocolitica mutant strains, including mutants deficient in the chaperone SycH resulting in a functional deficiency in tyrosine phosphatase (YopH), Mn-cofactored superoxide dismutase (SodA), iron-repressive protein 1 (IRP-1), and Yersinia adhesin A (YadA), were demonstrated to be highly attenuated in wild-type C57BL/6 mice. TNFRp55(-/-), IL-12p40(-/-), and IL-18(-/-) mutant mice, in which the Yersinia wild-type strain causes severe systemic infections, were used to investigate whether these Yersinia mutant strains would be attenuated in immunodeficient hosts. A plasmid-cured Yersinia mutant strain was unable to colonize any of the mutant mice tested. A SycH-deficient mutant strain colonized intestinal tissues of these mice but was attenuated for systemic infection in all of the mutant mice. Both YadA- and Irp-1-deficient Yersinia mutants were still attenuated in IL-12(-/-) and IL-18(-/-) mice but were pathogenic in TNFRp55(-/-) mice. By contrast, a Yersinia sodA mutant was highly pathogenic for TNFRp55(-/-) and IL-12p40(-/-) mice while interleukin-18 (IL-18) was dispensable. This finding demonstrates that certain virulence factors enable yersiniae to compete with distinct cytokine-dependent host defense mechanisms. Moreover, while gamma interferon mRNA expression did not reflect protective host responses in cytokine-deficient mice, IL-10 expression coincided with a heavy splenic bacterial load and was associated with progressive infection courses. We can thus segregate minor (SodA), intermediate (YadA and IRP-1), and major (YopH) virulence factors of Y. enterocolitica. Finally, we demonstrate that, even in immunocompromised hosts, Yersinia sycH and, with some restrictions, irp-1 mutants may be suitable for use as live carrier vaccines.