Introduction: Avian pathogenic Escherichia coli (APEC) is a leading cause of extraintestinal infection and heavy economic losses. Imparting immunity after vaccination with live attenuated strain vaccination is an ideal strategy for infection control. This study considers an FtsK knockout mutant strain as a candidate. Material and Methods: An FtsK knockout mutant of APEC strain E058 was constructed and the pathogenicity of the mutant and wild-type strains was further evaluated in chickens. Results: The 50% lethal doses of each strain for one-day-old specific-pathogen-free (SPF) chickens challenged experimentally via trachea were 105.5 and 107.0 colony-forming units (CFU) respectively. Chickens challenged with the wild-type strain exhibited typical signs and lesions of avian colibacillosis, while those inoculated with the mutant strain showed mild pericarditis and pulmonary congestion. The growth rate of the FtsK mutant strain was much slower than the wild-type strain in the heart, spleen, liver, and lung of infected chickens. Conclusion: These results indicated that the APEC FtsK mutant can be attenuated for chickens, and that this mutant has the potential for the development of an APEC vaccine.

Anualmente o tráfico de animais silvestres retira milhões de aves da natureza. Os cardeais (Paroaria coronata) e cardeais-do-nordeste (Paroaria dominicana) estão incluídos entre as espécies de aves mais traficadas. A microbiota cloacal de passeriformes de vida livre é composta principalmente por bacilos e cocos gram-positivos, já os bacilos gram-negativos predominam em aves de cativeiro. Em situações de estresse e baixa de imunidade as bactérias gram-negativas podem causar infecções oportunistas. O presente trabalho identificou bactérias da microbiota da cloaca de 49 espécimes de P. coronata e P. dominicana apreendidas do tráfico de animais silvestres em São Paulo (SP). Foram isoladas treze espécies de bactérias gram-negativas, incluindo Salmonella spp. e Pseudomonas aeruginosa. A maior frequência de ocorrência foi de Escherichia coli, identificada em 42/49 (85,7%) das amostras fecais. Dentre os isolados de E. coli, 21/42 pertenciam aos grupos filogenéticos B2 e D, relacionados a estirpes patogênicas que causam doença extraintestinal em humanos. Klebsiella pneumoniae foi isolada em 28/49 (57,1%) das amostras. Esses resultados reforçam que as condições estressantes a que esses animais são submetidos em situações de tráfico, incluindo o contato com humanos, podem favorecer a colonização da microbiota cloacal das aves por patógenos, o que representa um risco para a sua reintrodução na natureza considerando-se o possível contato com humanos e outros animais.

Introduction: Avian pathogenic Escherichia coli (APEC) is a leading cause of extraintestinal infection and heavy economic losses. Imparting immunity after vaccination with live attenuated strain vaccination is an ideal strategy for infection control. This study considers an FtsK knockout mutant strain as a candidate. Material and Methods: An FtsK knockout mutant of APEC strain E058 was constructed and the pathogenicity of the mutant and wild-type strains was further evaluated in chickens. Results: The 50% lethal doses of each strain for one-day-old specific-pathogen-free (SPF) chickens challenged experimentally via trachea were 10⁵.⁵ and 10⁷.⁰ colony-forming units (CFU) respectively. Chickens challenged with the wild-type strain exhibited typical signs and lesions of avian colibacillosis, while those inoculated with the mutant strain showed mild pericarditis and pulmonary congestion. The growth rate of the FtsK mutant strain was much slower than the wild-type strain in the heart, spleen, liver, and lung of infected chickens. Conclusion: These results indicated that the APEC FtsK mutant can be attenuated for chickens, and that this mutant has the potential for the development of an APEC vaccine.

Objective: The investigation was undertaken to measure the epidemiological features and antimicrobial sensitivity patterns of Escherichia coli among different breeds of goats in Cox's Bazar, Bangladesh.Materials and methods: A total of 150 rectal swab samples were collected from selected goats. The samples were subjected for the isolation of E. coli through a series of conventional bacteriological and biochemical techniques. The isolated E. coli were used for assessing antimicrobial susceptibility by disk diffusion method. Besides prevalence study, nine risk factors were studied; the risk factors were- breed, age, hygienic status, sex, history of recent transportation, season, diarrhea, body condition score, and source of drinking water. Results: The overall prevalence of E. coli in the rectal swabs of goats was 52% (n=78/150). The young goats were highly susceptible (65.0%; n=52/80) to E. coli infection as compared to adults (37.1%; n=26/70). The prevalence was higher (66.7%; n=42/63) in the goats that was reared in poor hygienic condition as compared to the goats that were reared under good hygienic condition. The influence of the source of drinking water on E. coli prevalence was found to be higher both in pond (63.6%; n=7/11) and municipality (61.4%; n=51/83) supplied water as compared to tube-well (35.7%; n=20/56). The goats having recent transportation history showed higher prevalence (64.8%; n=35/54). The prevalence was higher in diarrheic goats (62.0%; n=49/79) than non-diarrheic goats. Among the E. coli isolates (n=78), 31 were found to be multidrug resistant (MDR) to 3 to 8 subclasses of antimicrobials.Conclusion: Presence of MDR E. coli in the studied goats suggest the probable acquisition, development and transmission of MDR E. coli through a number of influencing factors to other animals and potentially to human. [J Adv Vet Anim Res 2016; 3(2.000): 166-172]

Objectives: The objective of this study was to isolate and identify Staphylococcus aureus and Escherichia coli from raw milk samples of cattle and buffalo, and to evaluate the antibiotic sensitivity pattern. Materials and methods: A total of 34 milk samples were collected twice from 17 different healthy cattle (n=14) and buffaloes (n=3) at one-month interval, and analyzed in laboratory by staining, cultural and biochemical characteristics followed by polymerase chain reaction targeting nuc gene of S. aureus and 16 S rRNA of E. coli. Antibiotic sensitivity pattern of the isolated bacteria was assessed using the disc diffusion method. Results: Confirmation of the isolates as S. aureus and E. coli were carried out by PCR using nuc gene, 16S rRNA gene specific primers specific for S. aureus and E. coli respectively. A total of 12 samples (35.29%; 11 from cattle, 1 from buffalo) were found to be positive for S. aureus; 5 and 7 during first and second month, respectively. The E. coli were found in three samples (2 from cattle, 1 from buffaloe); one in first month and two in the second month. The antibiotic sensitivity test using 4 commonly used antibiotics indicated that the most of the isolates were resistant to Gatifloxacin and one isolate showed intermediate resistance to Ofloxacin while sensitive to Ciprofloxacin and Levofloxacin.Conclusion: Two different species of bacteria i.e., S. aureus and E. coli are contaminating with milk samples. The pathogenic bacteria can be controlled effectively by using Ciprofloxacin and Levofloxacin in the case of mastitis in cattle and buffaloes in Bangladesh. [J Adv Vet Anim Res 2016; 3(1.000): 62-67]

Colibacillosis is animportant disease affecting the poultryindustry in many countries, caused bythe Avian Pathogenic E. coli (APEC):it manifests as various clinical signs. Itcontributes significantly to economicloss for poultry farmers as a result ofhigh mortality and morbidity in poultry.To overcome this, antibiotics have beenwidely used to eliminate E. coli infectionin poultry farms in recent years. Treatmentwith antibiotics has been considered as avital regimen to control E. coli infectionat the farm level for many years. However,high frequency of antibiotic resistance ofE. coli isolates from chicken has becomethe centre of attention due to public healthimportance. The aim of the present study isto determine the multidrug resistant profilesof E. coli strains isolated from chicken.E. coli isolates obtained from clinicalcases were re-identified and classified byconventional methods. Multidrug resistantprofiles against 13 different antibiotics of125 E. coli isolates were determined byusing disk diffusion method accordingto Clinical Laboratory Standard Institute(CLSI). Antibiogram revealed that 81.6%of the E. coli isolates showed multidrugresistant profiles to different antibiotics.Most of the E.coli isolates were highlyresistant to erythromycin (52.8%), followedwith tetracycline (52.0%), spectinomycin(39.2%), trimethoprim (38.4%) andflumequin (37.6%). Out of 125 isolatestested, 19.2% were resistant to more thaneight antibiotics, with one isolates found tobe multidrug resistant to most of antibioticsexcept polymyxin B. These findings alsodemonstrated that most of the isolateswere susceptible to antibiotics commonlyused for E.coli infections treatment inpoultry with lowest resistant score againstpolymyxin B (92.8%) and colistin (92.0%).Moderate resistant profiles were observedtowards amoxycilin (25.6%), apramycin(16%), kanamycin (8.8%) and streptomycin(8.0%). High percentage of multidrugresistance was found among the E. coliisolated from chicken as an indicator tomore serious problems in animal health.Therefore, continuous surveillance of antibiotic resistance profiles in chicken andother food animals is crucial to ensure foodchain safety

An observational study was conducted of chicken and turkey flocks slaughtered at federal processing plants in the province of Quebec, Canada. The objectives were to estimate prevalence of drug use at hatchery and on farm and to identify antimicrobial resistance (AMR) in cecal Escherichia coli and Enterococcus spp. isolates and factors associated with AMR. Eighty-two chicken flocks and 59 turkey flocks were sampled. At the hatchery, the most used antimicrobial was ceftiofur in chickens (76% of flocks) and spectinomycin in turkeys (42% of flocks). Virginiamycin was the antimicrobial most frequently added to the feed in both chicken and turkey flocks. At least 1 E. coli isolate resistant to third-generation cephalosporins was present in all chicken flocks and in a third of turkey flocks. Resistance to tetracycline, streptomycin, and sulfisoxazole was detected in > 90% of flocks for E. coli isolates. Antimicrobial resistance (AMR) was observed to bacitracin, erythromycin, lincomycin, quinupristin-dalfopristin, and tetracycline in both chicken and turkey flocks for Enterococcus spp. isolates. No resistance to vancomycin was observed. The use of ceftiofur at hatchery was significantly associated with the proportion of ceftiofur-resistant E. coli isolates in chicken flocks. In turkey flocks, ceftiofur resistance was more frequent when turkeys were placed on litter previously used by chickens. Associations between drug use and resistance were observed with tetracycline (turkey) in E. coli isolates and with bacitracin (chicken and turkey), gentamicin (turkey), and tylosin (chicken) in Enterococcus spp. isolates. Further studies are needed to provide producers and veterinarians with alternative management practices and tools in order to reduce the use of antimicrobial feed additives in poultry.

This study was conducted to investigate the high mortality of young lambs in two sheep farms in Pekan, Pahang over a period of 3 years. Samples from postmortem of 1,451 lambs below one year of age by a farm veterinarian were submitted for laboratory diagnosis at the Bacteriology Section of the Regional Veterinary Diagnostic Laboratory in Kuantan. Escherichia coli is the most commonly recorded bacteria with 161 lambs diagnosed in 2013. In 2014 and 2015, there was a decrease in occurrence of E. coli related deaths, with 120 and 75lambs respectively. A total of 25% of the cases showed Escherichia coli positive by culture on blood agar and MacConkey agar, and confirmed by biochemical tests. A total of 21% of the cases were positive for staphylococcus sp, 3% and 6% for Streptococcus sp and Klebsiella pneumonia, respectively. Other bacteria were isolated in 45% of the cases. It was further noted that a total of 285 lambs between the ages of one to four months of age followed by 58 lambs (20%) less than one month old had E.coli isolation. It is also noteworthy that there were 10 lambs with E.coli infection in one to fourteen day-old lambs during the 3-year period from January 2013 to December 2015. This information was collated as a result of routine diagnosis of field cases submitted and with the intention of highlighting the common pathogens causing high mortality in local small ruminant farms so that preventive action may be taken for future farming ventures. E. coli infections or Colibacillosis is an important finding and indicator of poor management including poor nutrition, hygiene and environmental contamination which can reduce animal immunity and render it susceptible to other infections.