Campylobacter jejuni colonization of broiler chickens

The pathogenesis of C. jejuni in broiler chickens is still poorly understood despite the importance of poultry meat as a source of infection in humans. The overall objective of this project was to understand the role of flagella and Campylobacter invasion antigens in mucosal and systemic colonization, and to evaluate the vaccine potential of C. jejuni paralyzed flagella mutants. As a first step to track C. jejuni in vivo, a Green Fluorescent Protein (GFP) reporter system that is constitutively expressed was constructed. The system was transformed into different C. jejuni strains and isolates, and their mucosal and systemic spreading was studied over the period of 7 days. C. jejuni NCTC11168V1 and V26 share the same background but differ in their ability to colonize chickens. C. jejuni 81-176 and K2-55 share the same genetic background but K2-55 has an insertion mutation in pflA gene that produced paralyzed flagella. Although the K2-55 flagella remained intact structurally, it did not secret Campylobacter invasion antigens (Cia). The reporter system was stable in all of these strains both in vitro and in vivo. Fluorescent bacteria were visualized successfully using fluorescent and confocal microscopes. C. jejuni NCTC11168V1 and 81-176 were detected in the intestinal tract and in the liver and spleen of more than 30% of the challenged birds, while V26 and K2-55 were only detected in the intestinal tract. C. jejuni 81-176 and K2-55 did not spread systemically to the spleen and liver of BALB/c mice challenged using the same approach, although they colonized the ceca. A live attenuated vaccine based on C. jejuni K2-55 protected broiler chickens from C. jejuni 81-176 challenge in chickens following streptomycin treatment of drinking water. The same vaccine had no significant protection against a heterolgous C. jejuni NCTC11168V1 strain challenge. The vaccine was a poor stimulator of secretory IgA. Macrophage-like HD11 cells inflammatory response to the presence of C. jejuni K2-55 was not significantly different from their response to wild-type 81-176 when measured by qRT-PCR. The lack of Cia secretion and motility had no effect on expression of IL-1â, IL-2, IL-6, IL-8, IL, IL-10, IL-12â, or TLR5. A flgK mutant expressing the flagella up to the hook had a significantly lower expression of these genes

Analysis of Resistance to Antimicrobials and Presence of Virulence/Stress Response Genes in Campylobacter Isolates from Patients with Severe Diarrhoea

Campylobacter infections are a major cause of diarrhoea world-wide and two of the antimicrobials used for their control (erythromycin and ciprofloxacin) have been losing efficacy in recent years. In a sample of 174 genotyped isolates from the stools of patients with severe diarrhoea in Qatar, collected between 2005 and 2012, 63.2%showed resistance to ciprofloxacin, 8.6% to erythromycin, 0.57%to chloramphenicol and all were sensitive to gentamycin. While 33.9%of isolates were sensitive to all four antimicrobials, 59.8% were resistant to at least one, 6.3% were resistant to two and none showed resistance to three antimicrobials. There was no host sex- or age-dependence among isolates resistant to ciprofloxacin and erythromycin and no significant variation was found with the region of origin of the patients. All isolates were screened for the presence of 3 virulence factors (ciaB, cadF and cdtB) and two stress-response factors (htrB and clpP), all of which were present in more than 50% of the isolates. Host sex-, age- and region of origin-dependent variations in prevalence were found for some of these factors. Data analysis for the combination of virulence factors and their effect on antimicrobial resistance indicated that the prevalence of resistance to both erythromycin and ciprofloxacin was higher in isolates harbouring ciaB but not clpP. Prevalence of resistance to ciprofloxacin was similar in clpP positive and negative isolates also possessing htrB, while for htrB-negative isolates prevalence was higher in the absence of clpP. These results are discussed and their implications are highlighted.National Priority Research Program grant number NPRP4-1283-3-327 from the Qatar National Research Fund, Hamad Medical Corporation grant #13334/1

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

Advances in vaccination against avian pathogenic Escherichia coli respiratory disease: Potentials and limitations

Avian pathogenic Escherichia coli (APEC) is one of the most economically devastating pathogens affecting the poultry industry. This group of extra-intestinal E. coli causes a variety of clinical conditions including airsacculitis and cellulitis. The economic impact of APEC is mainly due to mortality, slower growth rates, and carcass downgrading. In commercial broiler operations, APEC infections are controlled indirectly by vaccination against other respiratory diseases and minimizing stress conditions, and directly by administration of antimicrobial agents to suppress the infection in already infected flocks. The fact that most APEC strains possess some common virulence factors suggests that an effective vaccine against APEC is a viable option. The most important virulence factors that have been investigated over the years include type I and P fimbriae, aerobactin iron-acquisition system, and serum resistance traits. Despite the potential for developing an efficacious vaccine to combat this economically important poultry disease, several obstacles hinder such efforts. Those obstacles include the cost, vaccine delivery method and timing of vaccination as the birds should be immune to APEC by 21 days of age. Herein, we review the various attempts to develop an effective vaccine against the respiratory form of APEC diseases in poultry. We also discuss in-depth the potentials and limitations of such vaccines.NPRP grant number NPRP4 164-4-1 from the Qatar National Research Fund, a member of Qatar Foundation.Scopu

Prevalence of enteric bacteria in the stools of outpatients reporting to the MHC with severe diarrhoea in the period 2005–2013.

<p>The sample sizes for 2005–2013 were 2220, 1916, 2460, 2394, 2528, 2726, 3347, 4373 and 4176, respectively.</p

Prevalence of resistance to ciprofloxacin (A and B) and erythromycin (C) in <i>Campylobacter</i> isolates which were positive or negative for the <i>clpP</i> virulence factor, in the presence/absence of <i>CiaB</i> (A and C) and <i>htrB</i> (B).

<p>Sample sizes are given on the columns in A and B, and for C the sample sizes were the same as in A.</p

Prevalence of the virulence factor <i>ciaB</i> (A) and <i>htrB</i> (B) among male and female subjects in each of the age classes (A) and from each of the five regions of origin used for analysis (B).

<p>The sample sizes in A were as follows: for the 104 male subjects, 22, 24, 21, 26 and 11, and for the 70 female subjects 12, 20, 10, 17 and 11 for age classes 1–5 respectively in both cases. For the age span and average age of each age class see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0119268#sec002" target="_blank">Materials and Methods</a>. The sample sizes in B were as follows: for the 104 male subjects, 46, 18, 26, 11 and 3, and for the 70 female subjects 26, 15, 16, 10 and 3 for the five regions of origin (Qatar, Arabian Peninsula, Asia, Africa and elsewhere) respectively in both cases. For further details of countries of origin in each region see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0119268#sec002" target="_blank">Materials and Methods</a>.</p