Bacterial Shedding Research Articles

EspA-loaded mesoporous silica nanoparticles can efficiently protect animal model against enterohaemorrhagic E. coli O157: H7

In the present study, the application of mesoporous silica nanoparticles (MSNPs) loaded with recombinant EspA protein, an immunogen of enterohaemorrhagic E. coli, was investigated in the case of BALB/c mice immunization against the bacterium. MSNPs of 96.9 ± 15.9 nm in diameter were synthesized using template removing method. The immunization of mice was carried out orally and subcutaneously. Significant immune responses to the antigen were observed for the immunized mice when rEspA-loaded MSNPs were administered in both routes in comparison to that of the antigen formulated using a well-known adjuvant, i.e. Freund's. According to the titretitre of serum IL-4, the most potent humoral responses were observed when the mice were immunized subcutaneously with antigen-loaded MSNPs (244, 36 and 14 ng/dL of IL-4 in the serum of mice immunized subcutaneously or orally by antigen-loaded MSNPs, and subcutaneously by Freund’s adjuvant formulated-antigen, respectively). However, the difference in serum IgG and serum IgA was not significant in mice subcutaneously immunized with antigen-loaded MSNPs and mice immunized with Freund’s adjuvant formulated-antigen. Finally, the immunized mice were challenged orally by enterohaemorrhagic E. coli cells. The amount of bacterial shedding was significantly reduced in faecesfaeces of the animals immunized by antigen-loaded MSNPs in both subcutaneous and oral routes.

Effect of probiotics mix supplementation on haemato-biochemical parameters and bacterial faecal shedding in Corriedale lambs fed paddy straw based complete feed

Growth trial of 90 days was conducted on 12 male Corriedale lambs, divided in two groups of six lambs each, to study the effect of feeding of paddy straw based complete feed supplemented of probiotic mix (Saccharomyces cerevisiae 2×1010cfu/g + Lactobacillus acidophilus 6×109cfu/g) in equal ratio @ 3 % of DM, as per the in vitro studies, while complete feed without probiotics served as control. There was significantly (P less than 0.01) higher haemoglobin concentration, RBC, WBC and monocyte count in animals fed probiotic mix than control, with no significant effect on PCV, lymphocyte, eosinophill and neutrophill count. Blood glucose, total serum protein, albumin, globulin, BUN and serum creatinine values were statistically higher in probiotic mix supplemented animals. Lambs fed with probiotics show significant (P less than 0.01) decrease in serum cholesterol, LDL-cholesterol and triglycerides with increment of HDL-cholesterol than animals fed unsupplemented diet, with no effect on enzyme activities of liver enzymes. The lambs fed on probiotic mix shows significant reduction in faecal shedding of E. coli and total coliform with firm pellets faecal consistency. Probiotic mix has great potential to beneficially affect the haemato-biochemical parameters and gut micro-flora and hence improve physiological health status of animals.

The Impact of Vaccination and Prior Exposure on Stool Shedding of Salmonella Typhi and Salmonella Paratyphi in 6 Controlled Human Infection Studies

Shedding of Salmonella Typhi or Paratyphi in the stool or urine leads to contamination of food or water, which is a prerequisite for transmission of enteric fever. Currently, there are limited data on the effect of vaccination or prior exposure on stool shedding. Six Salmonella Typhi or Paratyphi human challenge studies were conducted between 2011 and 2017. Participants were either unvaccinated or vaccinated with 1 of 4 vaccines: Vi-polysaccharide (Vi-PS), Vi-tetanus-toxoid conjugate vaccine (Vi-TT), live oral Ty21a vaccine, or an experimental vaccine (M01ZH09). Daily stool cultures were collected for 14 days after challenge. There were 4934 stool samples collected from 430 volunteers. Participants who received Vi-PS or Vi-TT shed less than unvaccinated participants (odds ratio [OR], 0.34; 95% confidence interval [CI], 0.15-0.77; P = .010 and OR, 0.41; 95% CI, 0.19-0.91, P = .029 for Vi-PS and Vi-TT, respectively). Higher anti-Vi immunoglobulin G titers were associated with less shedding of S. Typhi (P < .0001). A nonsignificant reduction in shedding was associated with Ty21a vaccine (OR, 0.57; 95% CI, 0.27-1.20; P = .140). Individuals previously exposed to S. Typhi shed less than previously unexposed individuals (OR, 0.30; 95% CI, 0.1-0.8; P = .016). Shedding of S. Typhi was more common than S. Paratyphi. Prior vaccination with Vi vaccines, or natural infection, reduces onward transmission of S. Typhi. Field trials of Vi-TT should be designed to detect indirect protection, reflecting the consequence of reduced stool shedding observed in the human challenge model.

Shedding of Salmonella Typhimurium in vaccinated and unvaccinated hens during early lay in field conditions: a randomised controlled trial

BackgroundSalmonella vaccination is one of the control measure that farmers can use to reduce bacterial shedding in their flocks. This study aimed to examine the efficacy of the Vaxsafe® ST (Strain STM-1) attenuated live vaccine administered as ocular and oral doses followed by an intramuscular (IM) dose in rearing, in reducing contamination by Salmonellae of both eggs and the environment in the commercial multi-age cage layer sheds. A randomised controlled trial was conducted up to 26 weeks post last vaccine on two different multi-age caged egg farms.ResultsNo clinical symptoms were observed following IM administration of STM-1 during rearing. Following the first two STM-1 doses, both vaccinated and unvaccinated birds exhibited antibody titres below the positive cut-off value, however after IM administration of STM-1, antibody titres in the vaccinated group were above the cut-off value. Wild type Salmonella Typhimurium was not detected during the rearing of pullets. During production, the antibody titres were significantly higher in the vaccinated group at all sampling points during this trial. There was no significant difference in the prevalence of Salmonella (detected by culture and PCR method) between the vaccinated and unvaccinated groups on the egg belt and faeces in early lay. Wild-type Salmonella spp. were consistently found in dust samples. Quantitative PCR (qPCR) assay was able to differentiate between the live vaccine strain and wild type Salmonella. The load of wild-type Salmonella in shed environment was relatively low (1.3 log10 ± 0.48 CFU/m2 of surface area).ConclusionGiven that Salmonella Typhimurium and other serovars are able to survive/persist in the shed environment (such as in dust), regular cleaning and or removal of dust from shed is important. Use of the Vaxsafe® ST vaccine in multi-age flocks is “not an ultimate intervention” for reduction of Salmonella Typhimurium because of the complexities involved in achieving control, such as the efficacy of cleaning of sheds, the lack of resting periods between batches and the possible carry over of contamination from existing flocks. Hence implementation of more than one or several interventions strategies is essential.

Repurposing ebselen for decolonization of vancomycin-resistant enterococci (VRE).

Enterococci represent one of the microbial world’s most challenging enigmas. Colonization of the gastrointestinal tract (GIT) of high-risk/immunocompromised patients by enterococci exhibiting resistance to vancomycin (VRE) can lead to life-threating infections, including bloodstream infections and endocarditis. Decolonization of VRE from the GIT of high-risk patients represents an alternative method to suppress the risk of the infection. It could be considered as a preventative measure to protect against VRE infections in high-risk individuals. Though multiple agents (ramoplanin and bacitracin) have been evaluated clinically, no drugs are currently approved for use in VRE decolonization of the GIT. The present study evaluates ebselen, a clinical molecule, for use as a decolonizing agent against VRE. When evaluated against a broad array of enterococcal isolates in vitro, ebselen was found to be as potent as linezolid (minimum inhibitory concentration against 90% of clinical isolates tested was 2 μg/ml). Though VRE has a remarkable ability to develop resistance to antibacterial agents, no resistance to ebselen emerged after a clinical isolate of vancomycin-resistant E. faecium was serially-passaged with ebselen for 14 days. Against VRE biofilm, a virulence factor that enables the bacteria to colonize the gut, ebselen demonstrated the ability to both inhibit biofilm formation and disrupt mature biofilm. Furthermore, in a murine VRE colonization reduction model, ebselen proved as effective as ramoplanin in reducing the bacterial shedding and burden of VRE present in the fecal content (by > 99.99%), cecum, and ileum of mice. Based on the promising results obtained, ebselen warrants further investigation as a novel decolonizing agent to quell VRE infection.

Surgical masks as source of bacterial contamination during operative procedures

BackgroundSurgical masks (SMs) are used to reduce bacterial shedding from the mouth, nose and face. This study aimed to investigate whether SMs may be a potential source of bacterial shedding leading to an increased risk of surgical site infection. MethodsBacterial contamination of the SMs was tested by making an impression of the external surface of the mask on sterile culture media immediately. We investigated the difference in bacterial counts between the SMs worn by surgeons and those placed unused in the operating room (OR), and the bacterial count variation with indicated wearing time. Moreover, the difference in bacterial counts on the external surface between the first and second layers of double-layered SMs was also assessed. ResultsThe bacterial count on the surface of SMs increased with extended operating times; significant difference was found between the 4- to 6-hour and 0-hour groups (p < 0.05). When we analysed the bacterial counts from the same surgeon, a significant increase was noted in the 2-hours group. Moreover, the bacterial counts were significantly higher among the surgeons than the OR. Additionally, the bacterial count of the external surface of the second mask was significantly higher than that of the first one. ConclusionsThe source of bacterial contamination in SMs was the body surface of the surgeons rather than the OR environment. Moreover, we recommend that surgeons should change the mask after each operation, especially those beyond 2 hours. Double-layered SMs or those with excellent filtration function may also be a better alternative. The translational potential of this articleThis study provides strong evidence for the identification that SMs as source of bacterial contamination during operative procedures, which should be a cause for alarm and attention in the prevention of surgical site infection in clinical practice.

Cumulative protective efficacy of rZot and rAce combination in challenge experiments with wild type Vibrio cholerae in mouse model

ABSTRACTThe aim of this study was to assess the cumulative immunogenicity properties of rZot and rAce combination and their potential ability to increase the clearance rate of pathogenic standard Vibrio cholerae strain in challenge experiments in mice model. The recombinant Zot and Ace proteins were produced and used to raise polyclonal antibodies of anti-Zot and anti-Ace recombinant proteins in rabbit. Six-week female BALB/c mice were immunized with different antigens via oral route. Blood samples were collected, and the total amount of IgG and IgA antibodies against rZot and rAce were measured in blood and stool samples of each immunized mouse. Challenge experiments were done with toxigenic V. cholerae strain. The anti-Zot and anti-Ace IgG titers were significantly higher in immunized mice in comparison with control group. The IgG and IgA titers were higher in the sera of mice immunized by recombinant Ace than in group immunized by rZot, indicating the higher immunogenicity of rAce than rZot. The use of rAce and rZot mixture led to synergistic activities in increasing the level of IgG and IgA in comparison with the use of each protein separately. The clearance rate was significantly higher in different challenge groups than in the control group, and the coherence between rZot and rAce reduced the bacterial shedding significantly. In conclusion, the use of recombinant Zot and Ace mixture can produce the proper amount of IgA and IgG against to toxigenic V. cholerae, reduce bacterial shedding in immunized mice significantly, and be used as a potent candidate in cholera vaccine research.

A case of haemolytic uraemic syndrome (HUS) revealed an outbreak of Shiga toxin-2-producing Escherichia coli O26:H11 infection in a nursery, with long-lasting shedders and person-to-person transmission, Italy 2015.

Purpose. Shiga toxin-producing Escherichia coli (STEC) represents a major issue for public health because of the severity of the associated illnesses, including haemolytic uraemic syndrome (HUS). In 2015, investigation of a case of HUS revealed an outbreak of Shiga toxin-2-producing E. coli O26 : H11 infection in a nursery in Italy. The investigation showed that the infection was transmitted to cases' contacts via person to person.Methods. The case finding was performed by testing for STEC stool samples of the HUS case's contacts within the family and the nursery. STEC O26 isolates were characterized by whole genome sequencing. Confirmed cases were repeatedly tested to monitor the duration of STEC shedding.Results. Eleven STEC O26 cases were identified, including adults and asymptomatic patients. Clinical illness was only observed in children. Strain characterization revealed that a single clone harbouring the stx2a and eae genes and the complete array of STEC-associated virulence genes, belonging to ST(21), was implicated in the outbreak. To reduce bacterial shedding, patients were treated with cefixime following clinical recovery. This antibiotic was well tolerated and did not induce any apparent consequences on patients' health.Conclusions. This study confirms that Stx2-producing E. coli O26 represents an emerging public health problem. The occurrence of outbreaks of infection by Stx2-producing E. coli O26 in nurseries is of particular concern, given the high probability of infection progressing in severity and resulting in secondary cases.

Oral Bacterial Infection and Shedding in Drosophila melanogaster.

The fruit fly Drosophila melanogaster is one of the best developed model systems of infection and innate immunity. While most work has focused on systemic infections, there has been a recent increase of interest in the mechanisms of gut immunocompetence to pathogens, which require methods to orally infect flies. Here we present a protocol to orally expose individual flies to an opportunistic bacterial pathogen (Pseudomonas aeruginosa) and a natural bacterial pathogen of D. melanogaster (Pseudomonas entomophila). The goal of this protocol is to provide a robust method to expose male and female flies to these pathogens. We provide representative results showing survival phenotypes, microbe loads, and bacterial shedding, which is relevant for the study of heterogeneity in pathogen transmission. Finally, we confirm that Dcy mutants (lacking the protective peritrophic matrix in the gut epithelium) and Relish mutants (lacking a functional immune deficiency (IMD) pathway), show increased susceptibility to bacterial oral infection. This protocol, therefore, describes a robust method to infect flies using the oral route of infection, which can be extended to the study of a variety genetic and environmental sources of variation in gut infection outcomes and bacterial transmission.

Oral Bacterial Infection and Shedding in &lt;em&gt;Drosophila melanogaster&lt;/em&gt;

The fruit fly Drosophila melanogaster is one of the best developed model systems of infection and innate immunity. While most work has focused on systemic infections, there has been a recent increase of interest in the mechanisms of gut immunocompetence to pathogens, which require methods to orally infect flies. Here we present a protocol to orally expose individual flies to an opportunistic bacterial pathogen (Pseudomonas aeruginosa) and a natural bacterial pathogen of D. melanogaster (Pseudomonas entomophila). The goal of this protocol is to provide a robust method to expose male and female flies to these pathogens. We provide representative results showing survival phenotypes, microbe loads, and bacterial shedding, which is relevant for the study of heterogeneity in pathogen transmission. Finally, we confirm that Dcy mutants (lacking the protective peritrophic matrix in the gut epithelium) and Relish mutants (lacking a functional immune deficiency (IMD) pathway), show increased susceptibility to bacterial oral infection. This protocol, therefore, describes a robust method to infect flies using the oral route of infection, which can be extended to the study of a variety genetic and environmental sources of variation in gut infection outcomes and bacterial transmission.

Protective efficacy against live Chlamydia muridarum intravaginal challenge in BALB/c mice immunized with MOMP encapsulated PLGA 85/15 nanoparticles

Abstract Chlamydia trachomatis (Ct) remains the leading sexually transmitted bacterial infection worldwide but yet no vaccine to prevent its spread. Attempts to develop vaccines using whole or subunits have failed due to inefficient delivery systems. We have recently developed a Chlamydia nanovaccine by encapsulating its recombinant major outer membrane protein (rMOMP) in poly (lactic acid-co-glycolic acid) (PLGA) 85/15 nanoparticles (PLGA-rMOMP). In the current study, we assessed the systemic and mucosal antibody responses and the protective efficacy of the PLGA-rMOMP nanovaccine against a live C. muridarum (Cm) challenged infection in immunized mice. Female BALB/c mice were immunized subcutaneously three times at two weeks interval with 50 μg each of either PLGA-rMOMP or bare rMOMP and sacrificed two weeks after the last immunization to measure rMOMP-specific systemic and mucosal antibodies. Serum and cervico-vaginal washes were collected to measure IgG including subtypes IgG2a, IgG2b (Th1) and IgG1 (Th2) responses by ELISA. Immunized mice were challenged intravaginally with 105 inclusions forming units (IFUs) of Cm, swabs were collected for three weeks and cultured to quantify bacterial shedding by inoculating McCoy cells. PLGA-rMOMP immunized mice showed enhanced systemic and mucosal IgG antibodies response followed by IgG1 and IgG2b, as compared to bare rMOMP. Moreover, the PLGA-rMOMP immunization induced complete (60% of mice) and partial (40% of mice). Our results show that PLGA-rMOMP stimulates systemic and mucosal antibodies and provides protective efficacy against a Chlamydia infection in mice.

Broad-Spectrum Regulation of Nonreceptor Tyrosine Kinases by the Bacterial ADP-Ribosyltransferase EspJ.

ABSTRACTTyrosine phosphorylation is key for signal transduction from exogenous stimuli, including the defense against pathogens. Conversely, pathogens can subvert protein phosphorylation to control host immune responses and facilitate invasion and dissemination. The bacterial effectors EspJ and SeoC are injected into host cells through a type III secretion system by enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC, respectively), Citrobacter rodentium, and Salmonella enterica, where they inhibit Src kinase by coupled amidation and ADP-ribosylation. C. rodentium, which is used to model EPEC and EHEC infections in humans, is a mouse pathogen triggering colonic crypt hyperplasia (CCH) and colitis. Enumeration of bacterial shedding and CCH confirmed that EspJ affects neither tolerance nor resistance to infection. However, comparison of the proteomes of intestinal epithelial cells isolated from mice infected with wild-type C. rodentium or C. rodentium encoding catalytically inactive EspJ revealed that EspJ-induced ADP-ribosylation regulates multiple nonreceptor tyrosine kinases in vivo. Investigation of the substrate repertoire of EspJ revealed that in HeLa and A549 cells, Src and Csk were significantly targeted; in polarized Caco2 cells, EspJ targeted Src and Csk and the Src family kinase (SFK) Yes1, while in differentiated Thp1 cells, EspJ modified Csk, the SFKs Hck and Lyn, the Tec family kinases Tec and Btk, and the adapter tyrosine kinase Syk. Furthermore, Abl (HeLa and Caco2) and Lyn (Caco2) were enriched specifically in the EspJ-containing samples. Biochemical assays revealed that EspJ, the only bacterial ADP-ribosyltransferase that targets mammalian kinases, controls immune responses and the Src/Csk signaling axis.

Exploratory investigation of Q fever in apparently healthy meat sheep flocks in Belgium.

Q fever is a cosmopolitan disease affecting both humans and many animal species. Although sheep are often implicated in human Q fever outbreaks, the disease remains largely underestimated in meat sheep flocks. In order to fulfil this gap, a preliminary study was performed aiming to investigate the serological and molecular aspects of infection with Coxiella burnetii among meat sheep flocks in Belgium. Five Belgian sheep flocks were recruited for this work. Indirect ELISA was used, and in addition, real-time PCR was performed on samples of milk, rectal and vaginal swabs, to understand the dynamics of bacterial shedding. Despite the low overall apparent seroprevalence of 1.39% (95% CI: 0.04-7.5), a high rate of bacterial shedding was found, with 27.7% of tested sheep (N=72) with a positive result to PCR, especially through the rectal and vaginal routes and in seronegative animals. Furthermore, Coxiella burnetii DNA was detected in 26.76% of seronegative animals. It can be concluded that an overall good clinical condition of the sheep cannot be used to exclude the presence of C.burnetii in a flock. Furthermore in the diagnosis of Q fever in sheep, serology alone was not a sensitive diagnostic tool. On the contrary, molecular biology allowed to detect bacterial shedding, which is an essential element in order to assess the risk due to the contact with shedding animals. At the light of these results, the role of meat sheep flocks in the epidemiology of Q fever in Belgium needs to be better understood.

A novel inactivated vaccine against Lawsonia intracellularis induces rapid induction of humoral immunity, reduction of bacterial shedding and provides robust gut barrier function

Porcine proliferative ileitis is a major economic burden for the swine industry, affecting growing pigs and young adult pigs. In this study, the protective efficacy of an inactivated, injectable whole-cell bacteria vaccine against L. intracellularis – Porcilis® Ileitis was evaluated under field conditions.Eighty-five, three-week-old pigs on a commercial farrow-to-finish farm were vaccinated by the intramuscular route, either with a dose of injectable vaccine, or with saline. A subset of vaccinates and control pigs were necropsied at 21 days post-challenge. Incidence and severity of ileitis were evaluated by gross and microscopic observation of ileal tissues. Colonization of the gut after challenge was examined by L. intracellularis-specific immunohistochemistry, and qPCR of ileal scrapings. Integrity of the intestinal barrier was evaluated to quantify a range of intestinal markers including secreted mucin and intestinal alkaline phosphatase, and innate immune markers including Caspase-3 and Calprotectin. A second subset of pigs was monitored for fecal shedding of L. intracellularis, until resolution of shedding.Our investigation indicated that Porcilis Ileitis provided robust protection against ileitis, reduced bacterial shedding 15-fold (p < .05) and preserved normal gut barrier function in the face of an experimental challenge with virulent L. intracellularis.

Immunogenicity of the nanovaccine containing intimin recombinant protein in the BALB/c mice.

PurposeEscherichia coli O157:H7 is one of the most important pathogens which create hemorrhagic colitis and hemolytic uremic syndrome in human. It is one of the most prevalent causes of diarrhea leading to death of many people every year. The first diagnosed gene in the locus of enterocyte effacement pathogenicity island is eae gene. The product of this gene is a binding protein called intimin belonging to the group of external membrane proteins regarded as a good stimulants of the immune system. Chitosan with its lipophilic property is an environmentally friendly agent able to return to the environment.Materials and MethodsIntimin recombinant protein was expressed in pET28a vector with eae gene and purification was performed using Ni-NTA and finally the recombinant protein was approved through western blotting. This protein was encapsulated using chitosan nanoparticles and the size of nanoparticles was measured by Zetasizer. Intimin encapsulated was prescribed for three sessions among three groups of oral, injection, and oral-injection using Chitosan nanoparticles. Challenge was performed for all three groups with 108 E. coli O157:H7 bacteria.ResultsIntimin produced by chitosan nanoparticles improves immunological responses through the adjuvant nature of chitosan nanoparticles. Chitosan may be used as a carrier for transportation of the prescribed vaccine. Among the mice, encapsulated intimin could be able to provide suitable titers of IgG and IgA by the aid of chitosan nanoparticles. Results of mice challenge showed that decreased the bacterial shedding significantly.ConclusionResults showed that the chitosan nanovaccine with intimin protein may be used as a suitable candidate vaccine against E. coli O157:H7.

Domestic sheep show average Coxiella burnetii seropositivity generations after a sheep-associated human Q fever outbreak and lack detectable shedding by placental, vaginal, and fecal routes.

Coxiella burnetii is a globally distributed zoonotic bacterial pathogen that causes abortions in ruminant livestock. In humans, an influenza-like illness results with the potential for hospitalization, chronic infection, abortion, and fatal endocarditis. Ruminant livestock, particularly small ruminants, are hypothesized to be the primary transmission source to humans. A recent Netherlands outbreak from 2007–2010 traced to dairy goats resulted in over 4,100 human cases with estimated costs of more than 300 million euros. Smaller human Q fever outbreaks of small ruminant origin have occurred in the United States, and characterizing shedding is important to understand the risk of future outbreaks. In this study, we assessed bacterial shedding and seroprevalence in 100 sheep from an Idaho location associated with a 1984 human Q fever outbreak. We observed 5% seropositivity, which was not significantly different from the national average of 2.7% for the U.S. (P>0.05). Furthermore, C. burnetii was not detected by quantitative PCR from placentas, vaginal swabs, or fecal samples. Specifically, a three-target quantitative PCR of placenta identified 0.0% shedding (exact 95% confidence interval: 0.0%-2.9%). While presence of seropositive individuals demonstrates some historical C. burnetii exposure, the placental sample confidence interval suggests 2016 shedding events were rare or absent. The location maintained the flock with little or no depopulation in 1984 and without C. burnetii vaccination during or since 1984. It is not clear how a zero-shedding rate was achieved in these sheep beyond natural immunity, and more work is required to discover and assess possible factors that may contribute towards achieving zero-shedding status. We provide the first U.S. sheep placental C. burnetii shedding update in over 60 years and demonstrate potential for C. burnetii shedding to reach undetectable levels after an outbreak event even in the absence of targeted interventions, such as vaccination.

In vitro attenuation of a virulent swine isolate of Brachyspira hampsonii.

Brachyspira hampsonii causes dysentery-like disease in infected pigs. Serial passage of a virulent swine isolate (P13) one-hundred times in laboratory culture medium was conducted to produce an attenuated strain, and to identify genomic determinants of virulence through comparison of genome sequences of the original and passaged strains. The resulting strain, P113, did not differ from P13 in terms of diagnostic biochemical characteristics but had an enhanced growth rate in culture, indicating laboratory adaptation. Whole genome sequencing of P113 revealed several single-nucleotide changes including a T to C transition that results in an R to G amino acid change in a putative mannose-1-phosphate guanylytransferase that is implicated in production of lipo-oligosaccharide. P113 was partially attenuated in a mouse model of infection, indicated by significantly fewer observations of abnormal feces in mice infected with P113 relative to P13. No differences were detected in bacterial shedding in feces, demonstrating that the ability of the organism to colonize mice was not affected. Passage through a mouse did not further alter the virulence of P113. Results of this study provide insight into genomic determinants of virulence in B. hampsonii and a live attenuated vaccine candidate.

Prevalence of some Enteric Bacterial Infections Causing Rabbit Enteritis and Attempts to Control Rabbit Coli Enteritis with Phytobiotics

A field survey was conducted to monitor the prevalence of some enteric bacterial infections incriminated in rabbit enteritis outbreaks. Ninety bacterial isolates were recovered from diseased /or freshly dead rabbits with a history of severe diarrhea representing four farms in El-Sharkia Province. The predominant isolates were E. coli (24.29%), Klebsiella (14%), Proteus miriables (2.33%) and Proteus vulgaris (1.4%). All bacterial isolates were highly sensitive to levofloxacin. Isolated E. coli was later identified by using PCR. Fifty-three recently weaned White New Zealand rabbits were experimentally used to monitor the efficacy of two herbal extracts and probiotics (Healthy gut®; Immuplant plus®) supplementation with/or without enrofloxacin treatment in controlling artificial infection of the pathogenic streptomycin adapted E. coli isolate strain in a rate of (2.5 x 1010 CFU/0.1 mL/ rabbit orally) and improvement of growth parameters. Our results showed that; treatment with two (Healthy gut®; Immuplant plus®) induced an improvement in general health conditions and growth performance parameters with significant decrease in total labeled pathogenic E. coli shedding of infected supplemented group. In addition, this supplementation when followed by treatment with enrofloxacin after E. coli infection refluxed significant reduction of bacterial shedding with improvement of mean body weight and feed conversion ratio when compared with all other treated groups

Surgical Head Coverings: A Literature Review

Microorganisms that cause surgical site infections may either be present on the patient’s skin or mucous membranes or transmitted to the patient by health care personnel, the environment, or other items in the perioperative setting. This literature review analyzes the evidence used to support the recommendation that perioperative personnel should cover their heads, hair, and ears in the semirestricted and restricted areas. A literature search produced 27 articles related to bacterial shedding from skin and hair, pathogenic organisms present on the hair and ears, and case reports of infectious organisms passed from health care providers to patients. Although there is no conclusive evidence that wearing a head covering can help prevent surgical site infections, the potential benefits to patients when compared with the risks suggest that perioperative team members should cover their heads, hair, and ears in the semirestricted and restricted areas to provide the best possible protection for surgical patients.

Recurrent Urinary Tract Infections in the Setting of Mesh Implants

Mid-urethral polypropylene mesh slings are widely accepted as a standard for surgical management of stress urinary incontinence due to a low complication rate and superior efficacy. Synthetic mesh implants used to augment female pelvic prolapse repairs gained popularity following introduction of these slings. Mesh implants for prolapse have been under increased scrutiny after the FDA safety notification was published in 2008 due to a higher than anticipated complication rate. While the complication rate of mesh slings used for incontinence is low, both incontinence mesh and prolapse mesh are associated with similar types of complications. These include mesh exposure, pain, voiding dysfunction, and infections. The majority of available literature describes the incidence of acute urinary tract infections in the immediate postoperative period, specifically after mid-urethral sling procedures for incontinence. The rates of de novo recurrent urinary tract infections and risk factors for these infections after polypropylene mesh placement are not well-characterized. The incidence of recurrent urinary tract infections after polypropylene mesh-augmented surgery for stress urinary incontinence and for pelvic organ prolapse is low. Risk factors for recurrent urinary tract infections after surgery include urinary retention, need for indwelling or intermittent catheterization, and preoperative history of recurrent urinary tract infections. While multiple theories exist, the current literature has not been able to determine risk factors for de novo recurrent urinary tract infections after mesh-augmented surgery in women without urinary retention or prior history of recurrent urinary tract infections. While some have suggested that the implant is coated with a bacterial biofilm resulting in chronic low levels of bacterial shedding, and thus predisposing certain individuals to chronic recurrent urinary tract infections, this theory remains unproven. It is also not known if revision of the mid-urethral slings or if removal of the mesh implant in women in this subgroup will result in the resolution of recurrent infections.