Prevalence, molecular characterization, virulotyping, and antibiotic resistance of motile aeromonads isolated from Nile tilapia farms at northern Egypt

2020 ◽  
Vol 21 (1) ◽  
pp. 56-67 ◽  
Author(s):  
Mona Salem ◽  
Eman Zahran ◽  
Rawia Saad ◽  
Viola Zaki

Objective: This study was aimed to survey Aeromonas spp associated with cultured Nile tilapia Oreochromis niloticus (O. niloticus) showing signs of motile Aeromonas septicemia (MAS) at different fish farms; molecular characterization and identification of test isolates; and to test the isolates for their antimicrobial and virulence activities that contribute to its pathogenesis. Design: Observational study Animals: 280 Nile tilapia Procedures: Clinically diseased 280 Nile tilapia, were collected from different localities at Kafr El-Sheik and Dakahlia governorates. The clinical picture and gross lesions were recorded. Aeromonas spp were isolated and presumptively identified using API20E. The identification was confirmed using PCR. Hemolysin (hylA), lipase, and aerolysin (aerA) virulence genes were detected among isolates obtained from different sampling sites. Besides, antimicrobial activity was reported for the identified A. hydrophila. Results: General septicemic signs were evident on Nile tilapia including, skin hemorrhages and ulcerations, bilateral exophthalmia, congested internal organs with significant mortalities. The prevalence of bacterial infection among naturally diseased Nile tilapia was 79.17, 70, and 58.33 in Kafr El-Sheikh, El- Manzala, and Gamsa fish farms, respectively. The most prevalent bacterial isolates were aeromonads (29.84 %), of all, 65.63 A. hydrophila, 18.75 A. caviae, and 15.63 A. sobria. All isolates were positively amplified using a species-specifying primer to determine A. hydrophila. Virulence genes detection revealed that five A. hydrophila isolates (83.3 %) harbored the aerA gene. Meanwhile, hylA and lipase genes positive isolates were lower reaching 16.7 % for both genes. A. hydrophila was highly sensitive to ciprofloxacin, amikacin, trimethoprim, and chloramphenicol, and MAR index of A. hydrophila isolates was ranged from 0.16-0.42 Conclusion and clinical relevance: Our findings demonstrate that Aeromonas spp are among the bacterial pathogens implicated in summer mortalities in tilapia fish farms in Egypt. Besides, determination of the prevalence, virulence genes, and antibiotic resistance pattern associated with the disease outbreaks is critical data that warrant the development of strategies to proper monitoring and farm management practices.

Animals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1432
Author(s):  
Fatma A. El-Gohary ◽  
Eman Zahran ◽  
Eman A. Abd El-Gawad ◽  
Adel H. El-Gohary ◽  
Fatma M. Abdelhamid ◽  
...  

The aquaculture industry is a fast-growing sector in Egypt; however, the progress of this industry is impeded by many challenges such as poor water quality and associated bacterial infections. Among others, Motile Aeromonas Septicemia (MAS), caused by aeromonads, is among the most important bacterial diseases affecting aquaculture due to its zoonotic potential. In the present work, motile aeromonads were isolated from water samples (n= 8) and Nile tilapia (n= 240) in four fish farms (farms I, II, III, and IV) in Kafr El-Sheikh province during the period March to August 2017. This step was followed by investigation of the prevalence and phenotypic, molecular, and histopathological characterization of aeromonads. In addition, antimicrobial susceptibility and virulence gene detection were analyzed. Interestingly, physicochemical water analysis revealed different ranges in relation to the fish farms and seasons. More importantly, Aeromonas isolates were phenotypically identified in 33.3% and 12.5% from fish and water samples, respectively. The highest prevalence of motile aeromonads (46.7%) was recorded from farm IV, and only 12.5% of water samples were positive for them. Out of 80 isolates, 65 (81.25%) were molecularly identified at the genus level using gyrase B (gyrB). The prevalence of the virulence genes detected in the isolated motile aeromonads was aerolysin (aer), 52.2%; elastase (ahp), 26.25%; hemolysin (hyl), 35%; and lipase (lip), 3.75%. The antibiogram profile revealed that the highest resistance of aeromonads isolates (80%) was recorded to chloramphenicol, kanamycin, and azithromycin. Meanwhile, lower resistance levels of 40%, 30%, and 20% were found for streptomycin, cefotaxime, and amoxicillin, respectively. The multiple antibiotic resistance (MAR) index values ranged between 0.27 and 0.82 of motile aeromonads isolates. Furthermore, the histopathological examinations of naturally diseased tilapia revealed widespread hepatocellular necrosis with diffuse, numerous rod-shaped bacteria in liver with melanomacrophages and lymphocytic depletion with edema and hemosiderosis in the spleen. Our findings provide an updated epidemiological baseline for future reference and highlight the likely role of the adverse impact of water quality in the outbreaks of motile aeromonads with special reference to virulence genes and antibiotic resistant traits.


2021 ◽  
Author(s):  
Gururaj Kumaresan ◽  
Chetna Gangwar ◽  
Anil Kumar Mishra ◽  
Ashok Kumar ◽  
Suresh Dinkar Kharche ◽  
...  

Abstract Staphylococcus aureus is one of the most prevalent pathogens, and a causative agent of a variety of infections in humans and animals. A total of 48 semen samples were collected from healthy bucks of different breeds to investigate the prevalence of S. aureus . Antimicrobial resistance and virulence of the Staphylococcus isolates were determined to assess the adverse effects of them on buck fertility. The bacterial isolates were tentatively confirmed as Staphylococcus spp. based on the Gram’s staining, growth on Mannitol salt agar and catalase test. Overall, 75% (n = 36) of the samples were positive for Staphylococcus spp. from the total 48 buck semen ejaculates from different breeds. Out of 36 staphylococcal isolates, 23 (47.92%) were coagulase negative (CoNS) and 13 (27.08%) were coagulase positive Staphylococcus (CoPS) based on the slide coagulase test. In the current study, on the basis of molecular characterization, we identified S. aureus , S. chromogenes, S. haemolyticus, S. sciuri, S. simulans and S. epidermidis amongst the staphylococcal isolates in the buck semen. This study revealed a high prevalence of Staphylococcus species in semen of the healthy bucks. The isolates exhibited varying degrees of multidrug resistance genotypically as well as phenotypically. The presence of antibiotic resistance and virulence genes may pose a potential threat to reproductive health of animals, highlighting the need for vigilant monitoring of these isolates at the time of semen cryopreservation.


2020 ◽  
Vol 21 (3) ◽  
pp. 61-66
Author(s):  
Ola Hashem ◽  
Viola Zaki ◽  
Rawia Adawy

Objective: To study the incidence and seasonal dynamics of different fungi affected freshwater fishes in Lake Manzala with molecular identification of the isolated fungi. Animals: 300 Nile tilapia (Oreochromis niloticus) and 300 catfish (Clarias gariepinus). Design: Descriptive study. Procedures: Random samples of Oreochromis niloticus (O. niloticus) and Clarias gariepinus (C. gariepinus) were collected from Manzala fish farms. Clinical and postmortem examination of fish was applied. Isolation and identification of different fungi were performed by conventional methods. Furthermore, the molecular characterization of isolated fungi was carried out. Results: C. gariepinus had a higher rate of infection with different fungal species than O. niloticus. Aspergillus spp. (Aspergillus niger and Aspergillus flavus) were the most fungal isolated from the examined fishes, followed by Penicillium spp. and Candida albicans. Aspergillus spp were detected in all seasons with a higher rate in summer and spring. A. flavus, A. niger, Penicillium spp. and C.albicans isolates were amplified from both C. gariepinus and O. niloticus at the specified molecular weight using PCR. Conclusion and clinical relevance: Fungal infection affected the fish showing different external and internal lesions, all species of Aspergillus were found in all seasons with a high rate in, hot seasons, summer and spring. The Prevalence of Penicillium and C. albicans were also reported. All fungal isolates were identified on the phenotypic and molecular bases.


Gene Reports ◽  
2021 ◽  
pp. 101195
Author(s):  
Hossein Masoumi-Asl ◽  
Fatemah Sadeghpour Heravi ◽  
Ali Badamchi ◽  
Khadijeh Khanaliha ◽  
Marziye Farsimadan ◽  
...  

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Abdelazeem M. Algammal ◽  
Mahmoud Mabrok ◽  
Elayaraja Sivaramasamy ◽  
Fatma M. Youssef ◽  
Mona H. Atwa ◽  
...  

Abstract This study aimed to investigate the prevalence, antibiogram of Pseudomonasaeruginosa (P.aeruginosa), and the distribution of virulence genes (oprL,exoS, phzM, and toxA) and the antibiotic-resistance genes (blaTEM, tetA, and blaCTX-M). A total of 285 fish (165 Oreochromisniloticus and 120 Clariasgariepinus) were collected randomly from private fish farms in Ismailia Governorate, Egypt. The collected specimens were examined bacteriologically. P. aeruginosa was isolated from 90 examined fish (31.57%), and the liver was the most prominent infected organ. The antibiogram of the isolated strains was determined using a disc diffusion method, where the tested strains exhibited multi-drug resistance (MDR) to amoxicillin, cefotaxime, tetracycline, and gentamicin. The PCR results revealed that all the examined strains harbored (oprL and toxA) virulence genes, while only 22.2% were positive for the phzM gene. On the contrary, none of the tested strains were positive for the exoS gene. Concerning the distribution of the antibiotic resistance genes, the examined strains harbored blaTEM, blaCTX-M, and tetA genes with a total prevalence of 83.3%, 77.7%, and 75.6%, respectively. Experimentally infected fish with P.aeruginosa displayed high mortalities in direct proportion to the encoded virulence genes and showed similar signs of septicemia found in the naturally infected one. In conclusion, P.aeruginosa is a major pathogen of O.niloticus and C.gariepinus.oprL and toxA genes are the most predominant virulence genes associated with P.aeruginosa infection. The blaCTX-M,blaTEM, and tetA genes are the main antibiotic-resistance genes that induce resistance patterns to cefotaxime, amoxicillin, and tetracycline, highlighting MDR P.aeruginosa strains of potential public health concern.


Author(s):  
Mahdis Ghavidel ◽  
Tahere Gholamhosseini-Moghadam ◽  
Kimiya Nourian ◽  
Kiarash Ghazvini

Background and Objectives: Escherichia coli is known to be the pathogen commonly isolated from those infected with uri- nary tract infections (UTIs). The aim of this study was to investigate the presence of E. coli virulence genes and antibiotics’ resistance pattern among clinical isolates in the Northeast of Iran. Relationships between virulence genes and antimicrobial resistances were studied as well. Materials and Methods: Three hundred isolates of E. coli were isolated from patients with UTIs that referred to Ghaem and Imam Reza hospitals (Mashhad, Iran) during August 2016 to February 2017. A multiplex PCR was employed to amplify the genes encoding pyelonephritis associated pili (pap), S-family adhesions (sfa), type1fimbriae (fimH) and aerobactin (aer). Disk diffusion test was performed to test the susceptibility of isolates to β-lactams, aminoglycosides, cephalosporins, quino- lone, fluoroquinolones, carbapenems and trimethoprim-sulfamethoxazole. Results: The PCR results identified the fimH in 78.4%, aer in 70.5%, sfa in 13.6% and the pap in 8.2% of isolates. The rates of antibiotic resistance of the isolates were as follows: 64.7% resistant to cephalosporins, 34% to trimethoprim-sul- famethoxazole, 31% to fluoroquinolones, 15.3% to aminoglycosides, 13.3% to β-lactams, 7.8% to quinolones and 4.4% to carbapenems. Significant relationships existed between pap and aer, pap and sfa, aer and fluoroquinolones also pap and cephalosporins. Conclusion: fimH and aer were found in > 50% of isolates suggesting the importance of both genes in UPEC. The majority of isolates had fimH as adhesion factor for colonization. Determining antibiotic resistance patterns in specific geographical areas is necessary for appropriate treatment of urinary tract infection. The high rate of resistance to cephalosporins is most likely due to incorrect drug administration


Author(s):  
Saroj Sankhi ◽  
Rebanta Kumar Bhattarai ◽  
Hom Bahadur Basnet ◽  
Nirmal Raj Marasine ◽  
Himal Luitel ◽  
...  

This study aimed to identify, evaluate the antibiotic resistance pattern and detect virulence genes iss, and ompT in avian pathogenic Escherichia coli (APEC) from broiler chickens in central Nepal. To determine the antibiotic resistance pattern of the obtained isolates, the Kirby-Bauer disc diffusion method was used with six different commercial antibiotic discs: Amikacin, Gentamycin, Ciprofloxacin, Doxycycline, Chloramphenicol and Levofloxacin. A polymerase chain reaction (PCR) assay was used for the selected isolates (n=40) to screen the presence of the iss and ompT genes after the extraction of DNA using the boiling method Out of 60 suspected Colibacillosis liver samples, 40 were confirmed as E. coli positive The antibiogram profile revealed maximum resistance to Doxycycline (87.5%), followed by Levofloxacin (72.5%), Ciprofloxacin (67.5%), Chloramphenicol (40.0%), Gentamycin (32.5%) and Amikacin (10.0%).. The presence of the iss and ompT genes was found to be 100.0% and 90.0%, respectively. APEC was found to be highly resistant to most of the antibiotics. Virulence-associated genes iss and ompT were obtained at high percentages from Colibacillosis suspected broiler chickens in Chitwan, Nepal. These finding suggests that the judicial use of antimicrobials is compulsory to check antibiotic resistance and Colibacillosis outbreaks in poultry farms.


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