Efficacy of a prepared tissue culture-adapted vaccine against Chlamydia psittaci experimentally in mice.

BACKGROUND AND AIM: Chlamydia psittaci is an intracellular pathogen with a broad range of hosts and endemic in nearly all bird species as well as many mammalian species. Outbreaks contribute to economic losses, especially due to infection of pet birds, poultry, and livestock. Worse, the organism has a zoonotic effect, and transmission to humans results in severe illness. Therefore, proper control measures need to be applied. We conducted a trial for the preparation and evaluation of inactivated vaccine against C. psittaci. MATERIALS AND METHODS: Three C. psittaci strains (accession nos.: KP942827, KP942828, and KP942829) were grown in embryonated chicken eggs and then propagated for purification in Vero cells. The immunization experiment was experimentally performed in mice, which then were challenged with a virulent C. psittaci strain. RESULTS: The immunization trial revealed nearly 100% protection after the challenge. The histopathological and immunofluorescence examinations of internal organs revealed that the prepared killed vaccines can effectively reduce chlamydial infection and shedding in animals with the proper level of protection. CONCLUSION: Our vaccine can be used to control economic and financial losses resulting from avian chlamydiosis, especially those in poultry industries. The zoonotic transmission risk highlights the need for proper control measures.

Detection and antibiotic resistance of Mycoplasma gallisepticum and Mycoplasma synoviae among chicken flocks in Egypt.

BACKGROUND AND AIM: Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) are the most significant pathogens of avian mycoplasmosis. This study aimed to isolate and identify MG and MS from chickens and detect the various virulence genes in the isolates. Moreover, the efficacies of different antibiotics were tested to identify suitable treatment regimens. MATERIALS AND METHODS: We isolated MG and MS from 487 chicken samples of different ages located in different Governorates in Egypt using conventional isolation methods. The isolates were characterized by polymerase chain reaction (PCR) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and then tested for antibiotic sensitivity by the minimum inhibitory concentration (MIC) method. RESULTS: The prevalence of MG among the isolates was 9.85%, with the highest percentage isolated from air sacs, while the prevalence of MS among the isolates was 1.6%. Moreover, the highest levels of the prevalence of both MG and MS were during the winter and autumn sampling, while the lowest levels were in the summer and spring. Following the 16S rRNA-based detection of Mycoplasma isolates, 14 MG and 5 MS isolates were identified by different PCR-based detection methods for various virulence genes. Nine MG isolates contain the mgc2 gene, six MG isolates contain the gapA gene, and three MS isolates contain the vlhA gene. We validated a duplex PCR method for the simultaneous identification of MG and MS, based on 100% of the MG and MS isolates generating common bands at 55 and 17 kDa, respectively. The MIC method identified tiamulin and spiramycin as the antibiotics of choice for the treatment of MG and MS infections, respectively. CONCLUSION: For more precise diagnosis of Mycoplasma infections in chicken flocks, conventional isolation methods must be confirmed by PCR. SDS-PAGE analysis helps in epidemiological studies and vaccine preparation. The MIC method can be used to help develop therapies to control avian mycoplasmosis infections.

Genetic diversity of Salmonella enterica recovered from chickens farms and its potential transmission to human.

BACKGROUND: Salmonella is a zoonotic bacterium transmitted through the food chain and is an important cause of disease in humans. The current study is aimed to characterize Salmonella isolates from broiler breeder chickens farms using, polymerase chain reaction (PCR) and sequencing analysis of representative isolates. METHODS: S. Kentucky (n=11), S. Enteritidis (n=4), S. Typhimurium (n=3), S. Breanderp (n=1), and Sand S. Newport (n=1), were identified from chicken farms. Antimicrobial sensitivity test among the strains were investigated using 13 antibacterial discs. The amplified fragments of fliC and sefA genes were used to characterize S. Kentucky, S. Enteritidis and S. Typhimurium strains. Sequence analysis of the amplified PCR products for Salmonella Kentucky, Enteritidis and Typhimurium were carried out. RESULTS: Antimicrobial sensitivity testing revealed that 95% of the isolates were resistant to penicillin, 85% to norfloxacin and colistin sulfate (each), 75% to gentamicin, 70% to nalidixic acid and 60% to flumequine. The obtained sequences revealed the close identity of the isolated strains with other Salmonella reference strains in different countries. CONCLUSION: Analysis of the selected salmonellae confirm the report of Salmonella Enteritidis, Salmonella Typhimurium and Salmonella Kentucky circulation among broiler breeder flocks and the need to determine antibacterial susceptibility pattern regularly to detect multidrug-resistant salmonellae. The present study reports the circulation of Salmonella Kentucky, Enteritidis and Typhimurium among broiler breeder farms in Egypt. Emergency control of salmonellae is a global public health concern.

Isolation of antimicrobial producing Actinobacteria from soil samples.

Emergence of multidrug resistant bacteria has made the search for novel bioactive compounds from natural and unexplored habitats a necessity. Actinobacteria have important bioactive substances. The present study investigated antimicrobial activity of Actinobacteria isolated from soil samples of Egypt. One hundred samples were collected from agricultural farming soil of different governorates. Twelve isolates have produced activity against the tested microorganisms (S. aureus, Bacillus cereus, E. coli, K. pneumoniae, P. aeruginosa, S. Typhi, C. albicans, A. niger and A. flavus). By VITEK 2 system version: 07.01 the 12 isolates were identified as Kocuria kristinae, Kocuria rosea, Streptomyces griseus, Streptomyces flaveolus and Actinobacteria. Using ethyl acetate extraction method the isolates culture's supernatants were tested by diffusion method against indicator microorganisms. These results indicate that Actinobacteria isolated from Egypt farms could be sources of antimicrobial bioactive substances.

Occurrence of ampicillin-resistant Enterococcus faecium carrying esp gene in pet animals: An upcoming threat for pet lovers.

OBJECTIVES: This study was carried out to investigate oral colonisation by Enterococcus faecalis and Enterococcus faecium in pet dogs and cats, with special reference to antibiotic resistance. METHODS: Oral swabs were collected from 63 pet dogs and 57 pet cats with no known history of hospitalisation. All samples were enriched in Kenner Fecal (KF) broth before being cultured on KF agar to isolate enterococci. E. faecalis and E. faecium were identified by biochemical and molecular techniques. Antimicrobial resistance was determined by the disk diffusion method, and ampicillin-resistant strains were further examined by PCR to detect the esp gene. RESULTS: Oral prevalence rates of E. faecalis among pet dogs and cats were 3.2% and 5.3%, respectively, whilst those for E. faecium were 22.2% and 15.8%, respectively. None of the isolated enterococci were resistant to vancomycin. However, ampicillin-resistant E. faecium (AREfm) was detected in the examined dogs and cats at rates of 14.3% and 5.3%, respectively. Moreover, among the isolated enterococci, six isolates showed multidrug resistance (all AREfm). Whilst the esp gene was detected in only two of nine canine AREfm isolates (multidrug-resistant strains), none of feline AREfm isolates harboured esp. CONCLUSIONS: The occurrence of AREfm and the esp gene among oral isolates from pet dogs and cats represents a great public health hazard for pet owners and highlights possible zoonotic transmission of such a nosocomial pathogen outside healthcare facilities.

Leptospirosis in animals and human contacts in Egypt: broad range surveillance.

INTRODUCTION: Leptospirosis is a re-emerging zoonotic disease of humans and animals worldwide. The disease is caused by pathogenic species of the genus Leptospira. These organisms are maintained in nature via chronic renal infection of carrier animals, which excrete the organisms in their urine. Humans become infected through direct or indirect exposure to infected animals and their urine or through contact with contaminated water and soil. This study was conducted to investigate Leptospira infections as a re-emerging zoonosis that has been neglected in Egypt. METHODS: Samples from 1,250 animals (270 rats, 168 dogs, 625 cows, 26 buffaloes, 99 sheep, 14 horses, 26 donkeys and 22 camels), 175 human contacts and 45 water sources were collected from different governorates in Egypt. The samples were collected from different body sites and prepared for culture, PCR and the microscopic agglutination test (MAT). RESULTS: The isolation rates of Leptospira serovars were 6.9%, 11.3% and 1.1% for rats, dogs and cows, respectively, whereas the PCR results revealed respective detection rates of 24%, 11.3% and 1.1% for rats, dogs and cows. Neither the other examined animal species nor humans yielded positive results via these two techniques. Only six Leptospira serovars (Icterohaemorrhagiae, Pomona, Canicola, Grippotyphosa, Celledoni and Pyrogenes) could be isolated from rats, dogs and cows. Moreover, the seroprevalence of leptospiral antibodies among the examined humans determined using MAT was 49.7%. CONCLUSIONS: The obtained results revealed that rats, dogs and cows were the most important animal reservoirs for leptospirosis in Egypt, and the high seroprevalence among human contacts highlights the public health implications of this neglected zoonosis.

Leptospirosis in animals and human contacts in Egypt: broad range surveillance

INTRODUCTION: Leptospirosis is a re-emerging zoonotic disease of humans and animals worldwide. The disease is caused by pathogenic species of the genus Leptospira. These organisms are maintained in nature via chronic renal infection of carrier animals, which excrete the organisms in their urine. Humans become infected through direct or indirect exposure to infected animals and their urine or through contact with contaminated water and soil. This study was conducted to investigate Leptospira infections as a re-emerging zoonosis that has been neglected in Egypt. METHODS: Samples from 1,250 animals (270 rats, 168 dogs, 625 cows, 26 buffaloes, 99 sheep, 14 horses, 26 donkeys and 22 camels), 175 human contacts and 45 water sources were collected from different governorates in Egypt. The samples were collected from different body sites and prepared for culture, PCR and the microscopic agglutination test (MAT). RESULTS: The isolation rates of Leptospira serovars were 6.9%, 11.3% and 1.1% for rats, dogs and cows, respectively, whereas the PCR results revealed respective detection rates of 24%, 11.3% and 1.1% for rats, dogs and cows. Neither the other examined animal species nor humans yielded positive results via these two techniques. Only six Leptospira serovars (Icterohaemorrhagiae, Pomona, Canicola, Grippotyphosa, Celledoni and Pyrogenes) could be isolated from rats, dogs and cows. Moreover, the seroprevalence of leptospiral antibodies among the examined humans determined using MAT was 49.7%. CONCLUSIONS: The obtained results revealed that rats, dogs and cows were the most important animal reservoirs for leptospirosis in Egypt, and the high seroprevalence among human contacts highlights the public health implications of this neglected zoonosis. .

Sequencing analysis of Mycoplasma gallisepticum wild strains in vaccinated chicken breeder flocks.

Mycoplasma gallisepticum (MG) infection is still of continuing economic concern in commercial broiler breeder chicken flocks in Egypt. MG infection continues to emerge despite the application of vaccination programs in breeder flocks. This prompted flock surveillance including MG isolation and molecular characterization of the circulating MG strains. The present study was concerned with 15 broiler breeder flocks of different ages (5-51 weeks). Three flocks were apparently healthy and 12 flocks were diseased. The aim of the study was to characterize the MG strains recovered from tracheal swabs. Four positive MG DNA extracts identified by rt-PCR and confirmed by isolation were subjected to sequencing of the mgc2 gene and intergenic spacer region (IGSR). The current molecular study demonstrated the presence of 3 different wild-type MG strains (RabE1-08, RabE2-09 and RabE3-09) in vaccinated diseased flocks, while the fourth strain (RabE4-08), which was isolated from a nonvaccinated apparently healthy breeder flock, scored 100% of homology and similarity to the F-strain vaccine by the sequence analysis of mgc2 and IGSR. It can be assumed that the vaccine F strain, which is supposed to replace field strains not only failed to do that, but also infected nonvaccinated flocks. Accordingly, there is a need to revise the control program including vaccine strategy in parallel with biosecurity measures.