Yolk Sac Infection Research Articles

Plant Extract in the Control of Poultry Omphalitis.

Bacteria continue to disrupt poultry production and can cause resistant and persistent yolk sac infections to prevention efforts, known as omphalitis, resulting in poultry death. This literature review aims to demonstrate how plant extracts can help combat omphalitis in poultry. The Google Scholar database served as a resource for retrieving pertinent literature covering a wide range of search terms relevant to the scope of the research. The search strategy involved a combination of terms such as antimicrobials, chick embryo, omphalitis, plant extracts, poultry nutrition, and sanitization. The potential of plant extracts in preventing or treating infections in poultry, especially omphalitis, is mainly due to their antibacterial and safety properties. Sanitization and direct delivery of plant extracts to the internal contents of eggs, feed, or water are cutting-edge interventions to reduce the bacterial load in eggs and poultry, minimizing infection rates. For example, these interventions may include advanced treatment technologies or precise delivery systems focused on disease prevention in poultry.

Lameness caused by Staphylococcus aureus in poultry: A review

Staphylococcus aureus is a gram-positive, facultative anaerobe coccus, which is a member of the commensal microbiota of skin and mucous membranes in humans and animals and sometimes can cause infection or disease. This bacterium produces variable toxins and enzymes including at least five types of exotoxins that leads to cell membrane damage. Staphylococcus aureus can cause a wide range of clinical and pathologic lesions including acute or subacute septicemia, embryo mortalities, omphalitis and yolk sac infection, arthritis and synovitis, osteomyelitis, vesicular dermatitis, gangrenous dermatitis, pododermatitis and other disorders in different avian species. Staphylococcus aureus infections are among the most important diseases of poultry industry, particularly, in broiler breeder flocks. Staphylococcal infections can cause large economic losses due to lameness, arthritis, poor weight gain, decreased egg production, and loss of flock uniformity. This paper reviews the characteristics of Staphylococcus aureus and its role in lameness and arthritis in poultry.

Enhancement of protective efficacy of innate immunostimulant based formulations against yolk sac infection in young chicks

This study was conducted to characterize and compare the protective effects of various innate immune stimulants against yolk sac infection (YSI) caused by an avian pathogenic Escherichia coli in young chicks. The immune stimulants were administered alone or in various combinations of unmethylated CpG oligodeoxynucleotides (CpG), polyinosinic:polycytidylic acid (Poly I:C), and avian antimicrobial peptides (AMPs). Routes included in ovo or in ovo followed by a subcutaneous (S/C) injection. CpG alone and in combination with Poly I:C, truncated avian cathelicidin (CATH)-1(6-26), avian beta defensin (AvBD)1, and CATH-1(6-26) + AvBD1, were administered in ovo to 18-day-old embryonated eggs for gene expression and challenge studies. Next, CpG alone and the potentially effective formulation of CpG + Poly I:C, were administrated via the in ovo route using 40 embryonated eggs. At 1 day post-hatch, half of each group also received their respective treatments via the S/C route. Four hours later, all chicks were challenged using E. coli strain EC317 and mortalities were recorded for 14 d. The first challenge study revealed that amongst the single use and combinations of CpG with different innate immune stimulants, a higher protection and a lower clinical score were offered by the combination of CpG + Poly I:C. The second challenge study showed that this combination (CpG + Poly I:C) provides an even higher level of protection when a second dose is administered via the S/C route at 1 day post-hatch. The current research highlights the efficacy of a combination of CpG + Poly I:C administered either in ovo or in ovo along with a S/C injection and its potential use as an alternative to antibiotics against yolk sac infection in young chicks.

Exposure of embryonating eggs to Enterococcus faecalis and Escherichia coli potentiates E. coli pathogenicity and increases mortality of neonatal chickens

Enterococci and Escherichia coli are opportunistic pathogens of poultry and are associated with embryo and neonatal chick mortality. We have recently demonstrated that 56% of dead broiler chicken embryos in commercial hatcheries in western Canada were due to the coinfection of Enterococcus species and E. coli. The objective of this study was to investigate the host-pathogen interactions of Enterococcus faecalis and E. coli in developing chicken embryos. Embryonating eggs at 12 d of incubation were dipped in a solution of E. faecalis and/or E. coli for 30 s to expose the eggshell to study the migration and colonization of E. faecalis and E. coli in the internal organs of chicken embryos and subsequent neonatal chicken mortality following hatch. A multidrug-resistant E. faecalis isolate from a dead chicken embryo and an E. faecalis isolate from a case of yolk sac infection were able to colonize the internal organs of chicken embryos rapidly compared to an E. faecalis isolate from a healthy chicken without affecting viability or hatchability of embryos. Although E. faecalis colonized internal organs of chicken embryos, no evidence of inflammation of these organs nor the expression of virulence genes of E. faecalis was observed. Although E. faecalis and E. coli alone did not affect the viability of embryos, a significantly high neonatal chicken mortality (27%) was observed following exposure of embryos to both E. faecalis and E. coli. Upregulation of IL-1 and CXCR4 was evident 48 h before peak mortality of neonatal chickens; this could suggest a possible link of cytokine dysregulation to increased mortality in coinfected neonatal chickens. However, further studies are warranted to investigate this issue vis-à-vis coinfection with E. faecalis and E. coli in chicken embryos and neonatal chickens.

Characterization of Dosage Levels for In Ovo Administration of Innate Immune Stimulants for Prevention of Yolk Sac Infection in Chicks.

Innate immune stimulants, especially toll-like receptor (TLR) ligands and agonists, are the main players in the initiation of innate immunity and have been widely studied as alternatives to antibiotics to control infection. In the present study, we characterized the dosage levels of various innate immune stimulants, including unmethylated cytosine-phosphate-guanosine dinucleotide -containing oligodeoxynucleotides (CpG ODN), polyinosinic-polycytidylic acid (poly I:C), cyclic polyphosphazene 75B (CPZ75B), avian beta-defensin 2 (ABD2), and combinations of these reagents given in ovo. Data derived from a series of animal experiments demonstrated that the in ovo administration of 10–50 µg CpG ODN/embryo (on embryonic day 18) is an effective formulation for control of yolk sac infection (YSI) due to avian pathogenic Escherichia coli (E. coli) in young chicks. Amongst the different combinations of innate immune stimulants, the in ovo administration of CpG ODN 10 µg in combination with 15 µg of poly I:C was the most effective combination, offering 100% protection from YSI. It is expected that the introduction of these reagents to management practices at the hatchery level may serve as a potential replacement for antibiotics for the reduction of early chick mortality (ECM) due to YSI/colibacillosis.

An Integrated Perspective on Virulence-Associated Genes (VAGs), Antimicrobial Resistance (AMR), and Phylogenetic Clusters of Pathogenic and Non-pathogenic Avian Escherichia coli.

Avian pathogenic Escherichia coli (APEC) is an important bacterial pathogen that causes avian colibacillosis and leads to huge economic losses in the poultry industry. Different virulence traits contribute to pathogenesis of APEC infections, and antimicrobial resistance (AMR) has also been an overwhelming issue in poultry worldwide. In the present study, we aimed to investigate and compare the presence of virulence-associated genes (VAGs), AMR, and phylogenetic group's distribution among APEC and avian fecal E. coli (AFEC) strains. E. coli from birds with colisepticemia and yolk sac infection (YSI) (APEC) plus E. coli strains from the feces of healthy birds (AFEC) were compared by the aforementioned traits. In addition, the clonal relatedness was compared using Enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). Although all strains were susceptible to fosfomycin, ceftriaxone, and cefixime, almost all strains (98%) were multi-drug resistant (MDR). All strains (except two) harbored at least three or more VAGs, and the virulence scores tended to be higher in pathogenic strains especially in the colisepticemic group. All phylogenetic groups were found in isolates from YSI, colisepticemia, and the feces of healthy birds; however, the frequency of phylogroups varied according to the source of the isolate. B1 and C phylogroups were statistically more likely to be found among APEC from YSI and colisepticemic E. coli groups, respectively, while phylogroup A was the most frequently occurring phylogroup among AFEC strains. Our findings also revealed that AMR and VAGs are not essentially co-evolved traits as in some instances AMR strains were more prevalent among AFEC. This reflects the divergent evolutionary pathways of resistance acquisition in pathogenic or non-pathogenic avian E. coli strains. Importantly, strains related to phylogenetic group C showed higher virulence score and AMR that requires further attention. To some extent, ERIC-PCR was able to group strains by isolation source, phylogroup, or virulence genes. Further integrated studies along with assessment of more detailed genotypic and phenotypic features could potentially lead to better understanding of virulence, resistance, and evolution of ExPEC.

Antimicrobial resistance and genetic diversity of Enterococcus faecalis from yolk sac infections in broiler chicks

Despite restrictions on the use of antibiotics in poultry, the percentage of multidrug resistant bacteria, isolated from both adult birds and chicks, remains high. These bacteria can spread between countries via hatching eggs or chicks. Antibiotic resistant bacteria can also pose a threat to hatchery and farm workers or to consumers of poultry. The aim of the study was to perform a phenotypic and genotypic analysis of the drug resistance of E. faecalis isolates from yolk sac infections in broiler chicks from Poland and the Netherlands and to determine their genetic diversity. The tests revealed resistance to antibiotics from category D, that is, tetracycline (69.7%); category C – lincomycin (98.7%), erythromycin (51.3%), aminoglycosides (high-level streptomycin and kanamycin resistance – 10.5% and 3.95%, respectively), and chloramphenicol (7.9%); and category B – ciprofloxacin (25% with resistance or intermediate resistance). No resistance to penicillin, ampicillin, high-level gentamicin, tigecycline, or linezolid was noted. Various combinations of the erm(B), tet(M), tet(L), tet(O), ant(6)-Ia, aph(3′)-IIIa, ant(4′)-Ia, cat, and msr(A/B) genes were detected in all isolates (irrespective of the drug-resistance phenotype). Among isolates that carried the tet(M) and/or the tet(L) gene, 28% also had the Int-Tn gene, in contrast with isolates possessing tet(O). There were 28 sequence types and 43 PFGE restriction patterns. About 60% of isolates were of sequences types ST59, ST16, ST116, ST282, ST36, and ST82. Nine new sequence types were shown (ST836-ST844). In conclusion, broiler chicks can be a source of drug-resistant sequence types of E. faecalis that are potentially hazardous for people and animals. Restrictive programs for antibiotic use in broiler breeding flocks should be developed to decrease drug resistance in day-old chicks and reduce economic losses during rearing.

Avian antimicrobial peptides: in vitro and in ovo characterization and protection from early chick mortality caused by yolk sac infection

Increasing antibiotic resistance is a matter of grave concern for consumers, public health authorities, farmers, and researchers. Antimicrobial peptides (AMPs) are emerging as novel and effective non-antibiotic tools to combat infectious diseases in poultry. In this study, we evaluated six avian AMPs including 2 truncated cathelicidins, [CATH-1(6–26) and CATH-2(1–15)], and 4 avian β-defensins (ABD1, 2, 6 and 9) for their bactericidal and immunomodulatory activities. Our findings have shown CATH-1(6–26) and ABD1 being the two most potent avian AMPs effective against Gram-positive and Gram-negative bacteria investigated in these studies. Moreover, CATH-1(6–26) inhibited LPS-induced NO production and exhibited dose-dependent cytotoxicity to HD11 cells. While, ABD1 blocked LPS-induced IL-1β gene induction and was non-toxic to HD11 cells. Importantly, in ovo administration of these AMPs demonstrated that ABD1 can offer significant protection from early chick mortality (44% less mortality in ABD1 treated group versus the control group) due to the experimental yolk sac infection caused by avian pathogenic Escherichia coli. Our data suggest that in ovo administration of ABD1 has immunomodulatory and anti-infection activity comparable with CpG ODN. Thus, ABD1 can be a significant addition to potential alternatives to antibiotics for the control of bacterial infections in young chicks.

Phenotypic and genotypic characterization of Enterococcus spp. from yolk sac infections in broiler chicks with a focus on virulence factors

Bacterial infections of yolk sacs contribute to increased mortality of chicks, chronic infections during their rearing, or increased selection in the flock, which in turn leads to high economic losses in poultry production worldwide. The aim of this study was a phenotypic and genotypic characterization of enterococci isolated from yolk sac infections (YSI) of broiler chickens from Poland and the Netherlands. Biochemical, matrix-assisted laser desorption/ionization (MALDI)–time-of-flight (TOF) MS, and rpoA gene sequencing identification was performed. Moreover, phenotypic and genotypic characterization of virulence factors and analysis of the clonal relationship of isolates by MALDI-TOF MS and enterobacterial repetitive intergenic consensus—polymerase chain reaction (ERIC-PCR) were performed. The biochemical test identified 70 isolates as Enterococcus faecalis and 6 as Enterococcus mundtii. The results of MALDI-TOF MS were 100% concordant with those obtained by rpoA gene sequencing, and all 76 isolates were identified as E. faecalis. Differences were noted in the β-glucuronidase, β-glucosidase, α-galactosidase, phosphatase, melibiose, lactose, and raffinose tests that is going about the results of biochemical identification. None of the isolates were beta-hemolytic on blood agar in aerobic conditions, but all but one were gelatinase positive. Among biofilm-forming isolates (30/76; 39.5%), as many as 66.7% (20/30) were Polish E. faecalis strains. Most of the isolates carried virulence genes, that is gelE, ace, asa1, efaAfs, fsrA, fsrB, fsrC, cob, cpd, and ccf, but none had the hyl gene. Some isolates harbored cyl operon genes. One Polish strain (ST16) had all of the tested cyl genes and the esp gene, considered clinically important, and showed the highest biofilm-forming ability. Nearly 50% of the isolates showed close genetic relatedness in ERIC typing. In contrast with MALDI-TOF MS cluster analysis, ERIC-PCR results did not show a relationship with the origin of the strains. Using MALDI-TOF MS, 7 peaks were found in Polish and Dutch isolates, which may type them as species-specific biomarkers in E. faecalis from YSI.

Risks and disease aetiologies of compromised performance in commercial broilers kept at lower stocking density and limited antimicrobial use

ABSTRACT The health status of broilers raised at lower stocking density and limited antimicrobial use (but routine anticoccidials) was assessed in order to identify prevalent causes of disease, mortality and reduced performance. “Dead-on-farm”(DOF) broilers from 145 commercial flocks were investigated at two different time points (TP1:7–14 and TP2:28–35 days of age); per sampling, 6–10 DOF broilers were selected for post-mortem investigation and gross pathomorphological changes were assessed from 2717 birds in total. Post-mortem findings were substantiated by bacteriological, virological and parasitological investigations. Furthermore, production data of all flocks were collected and used to perform comprehensive statistical analysis. Overall, colibacillosis was found most important with a significant negative impact on flock health, productivity and profitability through all ages of broiler production. At TP1, primary reasons for mortality comprised yolk sac infections, generally found together with fibrinous polyserositis due to E. coli. Furthermore, femoral lesions, which correlated with increased flock mortality, were associated with detection of E. coli. At TP2, ascites was detected frequently in DOF broilers, correlating with increased production losses in the fourth and fifth weeks of life. No aetiological link between the presence of ascites and the detection of the investigated pathogens was observed, instead a positive correlation was noticed with altitude above sea level of the farm, and with the sex of the birds. Disease conditions could not be linked with the housing system. Presence of infectious bronchitis virus, avian reovirus and fowl adenovirus did not correlate with macroscopic lesions or a specific disease. RESEARCH HIGHLIGHTS In young broilers lesions of visceral organs due to bacterial infections dominated. Colibacillosis impacts broiler health, productivity and profitability independent of the age of birds. Disorders of the locomotor system were frequently observed throughout production. Older broilers frequently showed pathologic changes due to metabolic disorders. Overall, a shift from infectious towards metabolic disease conditions was noticed.

Prevalence of Multiple Drug Resistance among Avian Pathogenic E. coli Isolates from Commercial Poultry

Infections associated with Avian Pathogenic E. coli are responsible for huge economic losses for poultry industry worldwide. Particularly, its association with colibacillosis, a complex syndrome which is characterized by lesions of multiple organs i.e. peritonitis, pericarditis, air Sacculitis, osteomyelitis, salpingitis and yolk sac infections is responsible for high mortality and morbidity. Moreover, it causes respiratory tract infections among poultry birds, followed by septicaemia. Liver samples were collected from commercial poultry birds from the various retail shops located in Peshawar City. Bacteria were identified by biochemical and molecular methods. Out of all the tested isolates n=85, 98% were identified as Avian Pathogenic E. coli (APEC). Identified APEC samples were further tested against 23 different antibiotics including amoxicillin (89.40%), levofloxacin (62.40%), ciprofloxacin (71.80%), tobramycin (14.10%), gentamycin (34.10%),neomycin (53.00%), streptomycin (81.00%), tigecyclines (0.00%), oxytetracyclines (96.50%), doxycycline (61.20%), nitrofurantoin (1.00%), chloramphenicol (63.50%), cefixime (7%), cefepime (4.70%), ceftazidime (8.30%), cefotaxime (8.00%), cephalothin (43.50%), trimethoprim, sulfamethoxazole (77.60%), lincomycin (100%), augmentin (4.70%), carbapenem (4%) and polymyxin B (15%). Out of all n=85 isolates 99.9% were multi-drug resistant. Furthermore, ESBL encoding TEM, OXA, SHV were detected in following percentages 53.60%, 19.50%, 9.70% respectively genes.

Mortality and Early Feeding Behavior of Female Turkey Poults During the First Week of Life.

Turkey poults are susceptible to early mortality and poor initial feeding behavior for reasons that are not well-understood. This study was conducted to investigate the relationship between the development of turkey poult feeding behavior and early mortality, with a focus on the effect of biological age and diet. We hypothesized that increasing biological age would increase mortality, and that poults that had earlier feeding behavior would have decreased mortality. Nine hundred and sixty female turkey poults were randomly assigned to 24 pens (40 poults per pen). The study was conducted as a completely randomized block design with a factorial arrangement of two ages (early and standard hatch) and three diets (control, modified A, and modified Ca/P B, differing primarily in the Ca/P ratio and percent fines). The behavior during the first 24 h after placement of newly placed poults was examined. Growth performance and mortality throughout the first week of life was also measured to determine if early behavior had any impact on these variables over time. Behavior during the first 24 h was similar between the age treatments; both spent ~2.5% of the time drinking, 7% of the time feeding, 12% of the time active and 80% of the time inactive/resting. There was no effect of diet or age treatment on latency to feed or drink. Growth variables were not affected by biological age. However, there was a significant diet and biological age effect on bodyweight and mortality. Standard hatch poults fed a control diet were lighter than other poults at 7 d, while standard hatch poults fed the diet with the lowest Ca:P had the highest mortality. For all treatments, early mortality was primarily due to yolk sac infection, although >1% of placed poults died due to starvation. Findings of the present study indicate that, regardless of biological age or diet, poults established feeding behavior within the first 24 h and the majority of early poult mortality under these experimental conditions was due to factors other than starvation.

An In Vivo and In Vitro Trial on Layer Chicken Breed Susceptibility and Yolk Sac Infection to Escherichia Coli and Evaluation of the Immune Response in Bishoftu Poultry Farms , Central Ethiopia

An In Vivo and In Vitro Trial on Layer Chicken Breed Susceptibility and Yolk Sac Infection to Escherichia Coli and Evaluation of the Immune Response in Bishoftu Poultry Farms , Central Ethiopia

Prevalence of Fowl Adenovirus Infection in Broilers and Kadaknath Birds in Malwa Region of Madhya Pradesh

study was conducted to study the prevalence of Fowl adenovirus infections in broilers and Kadaknath birds in Malwa region of Madhya Pradesh during July 2016- March 2017. Overall 2.78% mortality was recorded at 30 broiler farms. Total mortality recorded at Kadaknath farms was 6.84%. Age-wise highest mortality in broiler farms was recorded at 3rd week of age and highest mortality was recorded at 1st week and 3rd week of age respectively at Mhow and Jhabua kadaknath farms. Disease-wise highest mortality in broilers was recorded due to IBH-HPS (1.6%) followed by colibacillosis. At Kadaknath farm Mhow and Jhabua maximum mortality was recorded due to yolksac infection (2.83%) and coccidiosis (1.90%) respectively.

RETROSPECTIVE STUDY OF MORTALITY IN CAPTIVE STRUTHIONIFORMES IN A FRENCH ZOO (1974-2015).

The husbandry and medical records, and necropsy reports, of 1,002 captive Struthioniformes that died at the Réserve Africaine de Sigean (France) from 1974 to 2015 were examined. The goal of this study was to determine the most common causes of mortality in ostriches ( Struthio camelus), emus ( Dromaius novaehollandiae), and American rheas ( Rhea americana), in order to highlight common causes of mortality, as well as the influence of age, gender, and rearing methods on mortality. The most prevalent cause of mortality was pathology of digestive origin in the neonates of all three species, especially yolk-sac infections, which accounted for 41% of all deaths in this captive neonate population and was especially prevalent in hand-reared neonates. Other causes included musculoskeletal disorders in emus (particularly hand-reared) and rheas; trauma in neonate ostriches, mainly due to crushing by parents; leg deformities in emu chicks and juveniles; general sepsis in hand-reared ratite chicks due to a chlamydiosis outbreaks (1989-1990); trauma by conspecifics in subadult ostriches and emus; stress myopathy in subadult rheas, particularly after introduction to a new enclosure; evisceration inflicted by herbivorous enclosure mates on adult male ostriches; fatal peritonitis following salpingitis in adult female ostriches; and death associated with ocular disorder in adult male emus. Although this study was conducted at one institution, and its results reflect this zoo's management and zootechnical practices, its findings could well have implications for management practices involving other captive Struthioniforme populations.

In Ovo Administration of Innate Immune Stimulants and Protection from Early Chick Mortalities due to Yolk Sac Infection.

Omphalitis or yolk sac infection (YSI) and colibacillosis are the most common infectious diseases that lead to high rates of early chick mortalities (ECMs) in young chicks. Out of numerous microbial causes, avian pathogenic Escherichia coli (APEC) or extraintestinal pathogenic E. coli infections are considered the most common cause of these conditions. YSI causes deterioration and decomposition of yolk, leading to deficiency of necessary nutrients and maternal antibodies, retarded growth, poor carcass quality, and increased susceptibility to other infections, including omphalitis, colibacillosis, and respiratory tract infection. Presently, in ovo injection of antibiotics, heavy culling, or after hatch use of antibiotics is practiced to manage ECM. However, increased antibiotic resistance and emergence of "super bugs" associated with use or misuse of antibiotics in the animal industry have raised serious concerns. These concerns urgently require a focus on host-driven nonantibiotic approaches for stimulation of protective antimicrobial immunity. Using an experimental YSI model in newborn chicks, we evaluated the prophylactic potential of three in ovo-administered innate immune stimulants and immune adjuvants for protection from ECM due to YSI. Our data have shown >80%, 65%, and 60% survival with in ovo use of cytosine-phosphodiester-guanine (CpG) oligodeoxynucleotides (ODN), polyinosinic:polycytidylic acid, and polyphosphazene, respectively. In conclusion, data from these studies suggest that in ovo administration of CpG ODN may serve as a potential candidate for replacement of antibiotics for the prevention and control of ECM due to YSI in young chicks.

REVIEW OF MORTALITY AND EFFECTIVENESS OF NEONATAL TREATMENT IN CAPTIVE ATTWATER'S PRAIRIE CHICKENS ( TYMPANUCHUS CUPIDO ATTWATERI).

A retrospective study of mortality and neonatal treatment for 975 Attwater's prairie chickens ( Tympanuchus cupido attwateri) was conducted from 2009-2015. Gross necropsy, histopathology, and medical records for chicks less than 8 wk of age at the Houston Zoo were reviewed and summarized. The total mortality rate was 36% ( n = 352). Yolk sac infection was the most common cause of death (21%; n = 73) followed by maladaptation (19%; n = 68), musculoskeletal abnormalities (19%; n = 66), necrotic enteritis (13%; n = 44), and mucoid enteritis (11%; n = 39). Gavage feeding of a highly digestible formula was associated with a higher proportion of necrotic enteritis and a reduced occurrence of both mucoid enteritis and maladaptation. Meloxicam administration had a significantly reduced incidence of mucoid enteritis. Survival past 10 days of age, prevention of neonatal bacterial infection, and supportive treatment with meloxicam are important factors to increase chick survival and improve captive breeding success for Attwater's prairie chickens. Gavage feeding of a diet low in digestible carbohydrates has the potential for reducing disease due to necrotic enteritis in this species.

ECOR phylotyping and determination of virulence genes in Escherichia coli isolates from pathological conditions of broiler chickens in poultry slaughter-houses of southeast of Iran.

Avian pathogenic Escherichia coli (APEC) are responsible for wide ranges of extra-intestinal diseases in poultry including colibacillosis, cellulitis, coligranuloma and yolk sac infection. Numbers of virulence are considered important in the pathogenicity of these diseases. The aims of the present study were phylogenetic typing and virulence genes detection in Escherichia coli isolates from colibacillosis and cellulitis of broiler chickens in poultry slaughterhouses of Shahrbabak region, Kerman, Iran. A total number of eighty three E. coli isolates were taken from broiler chickens with colibacillosis and thirty four isolates were taken from carcasses with cellulitis in the industrial slaughterhouses. Biochemically confirmed E. coli isolates were subjected to polymerase chain reaction assay to determine phylogenetic groups and presence of pap C, sfa/focDE, iucD, afaIB-C, hlyA, fimH and crl virulence genes. Colibacillosis isolates were belonged to A (54.21%), B1 (7.22%), B2 (6.03%) and D (32.53%) phylogroups. Whereas, the isolates from cellulitis cases were belonged to three main phylogroups; A (55.88%), B1 (5.88%) and D (38.24%). Statistical analysis showed a specific association between the presence of crl virulence gene and phylogroups of A and D in colibacillosis isolates. The results showed that the isolates from both diseases in broiler chickens could be assigned to various phylogenetic groups (mainly A(. Also, the virulence genes profile of cellulitis E. coli is completely different from that of colibacillosis in this region.

English

A study was conducted from November 2014 to June 2015 at three hatcheries designated as A, D and E in Bishoftu Town, Ethiopia, to isolate and identify bacteria associated with yolk sac infection and to determine antimicrobial susceptibility profile of the predominant isolates. A total of 385 Lohmann and Koekoek breed, 1 to 7 days old chicks suffering from yolk sac infection were examined from three different hatcheries of which 96.1% (N=370) of them were showing unabsorbed yolk sac. All the chicks were necropsied and yolk sac samples were collected for isolation and identification of bacteria followed by testing of the isolates for their susceptibility to 11 antimicrobial agents using disc diffusion method. A total of 323 bacterial isolates were identified, of these Escherichia coli were the most common bacteria (N=116; 35.91%) isolated followed by Salmonella species (N=111; 34.36%) and Staphylococcus aureus (N=96; 29.72%). Significant difference (P<0.001) was noted among the hatcheries on the frequency of isolation of the predominant bacteria species from yolk sac samples with the highest rate of isolation being in hatchery A. All the tested predominant bacterial isolates showed higher susceptibility to Gentamicin, Chloramphenicol, Amikacin (except S. aureus) and Kanamycin but were resistant to Ciprofloxacin, (except S. aureus), Penicillin G, Tetracycline, Sulfamethoxazole  and Amoxicillin (except S. aureus). The existence of multi-drug resistant bacteria isolates associated with yolk sac infection suggests that more emphasis should be given towards preventing omphalitis in chicks through improvements of sanitary measures at hatcheries than to use antimicrobials to control infections.   Key words:  Bacteria, chicken, yolk sac infection, antimicrobial sensitivity, Ethiopia.

Klebsiella spp. in the pathology of poultry and their role in epidemiology of human foodborne diseases

One of the important problems, increasing successively, in intensive poultry production are bacterial infections, and the major reason of this inconvenient situation is increasing resistance of bacteria to antibiotics. In most cases infections are caused by bacteria belonging to the family Enterobacteriaceae, especially Escherichia coli and Salmonella spp. Additionally, bacteria Klebsiella spp. are isolated from many pathological conditions of poultry. To date these bacteria were isolated from dead embryos, yolk sac infections, pathological conditions associated with ascites, cellulitis, diseases with respiratory symptoms and from skin swabs of poultry carcasses. Klebsiella spp. are considered to be microbes of low pathogenicity, but in the case of birds’ immunosuppression they can intensify the course of primary infections. Moreover, an alarming fact is the very wide antimicrobial resistance of strains of these bacteria, and Klebsiella spp. is the frequent cause of critical infections in humans. The presence of these bacteria in poultry, and therefore the possibility of contamination of poultry carcasses, especially if processed without correct heat treatment, may serve as a source of infections for humans, which has been described in the past in studies with the use of phylogenetic analysis.