Role of Aeromonas hydrophila in bacterial septicemia of cultured carps in Khouzestan Province and investigation on protectivity of bacterin (s) prepared from acute isolate(s) of it

Motile Aeromonas are the most common bacteria of freshwater in the world that cause disease in fish and other cold-blooded and warm-blooded hosts. Among this group of bacteria, Aeromonas hydrophila is important in causing complications such as fin rot, skin ulcers and lethal hemorrhagic septicemia in fish. Several virulence factors involved in the pathogenesis of Aeromonas hydrophila, including extracellular enzymes (protease, lipase, elastase, gelatinase and nuclease) and toxins. From the exotoxins, hemolysin, aerolysin and cytolytic enterotoxin play an important role in pathogenesis. Detection of virulence markers by PCR as a key component of determining the pathogenesis of the bacteria and using indigenous vaccines for better immunization against this disease is important. In this study, a total of 200 fanned carps (126 common carp. 39 silver carp and 35 of grass carp) with symptoms suspected aeromonas septicemia were isolated from Khouzestan province farms. 125 bacteria belong to Aeromonas genus detected by biochemical and PCR methods. 31 of all isolates recognized as Aeromonas hydrophila with biochemical methods, I6srRNA detection and Lipase genes. Results showed that the role of Aeromonas sp. and Aeromonas hydrophila in fish with disease symptoms were 62.5% and 15.5% respectively. By using specific primers, three virulence genes including hemolysin, aerolysine and cytolytic enterotoxin were detected in these confirmed isolates, that 18 isolates (58/06%) hemolysin positive (hlyA +), 16 isolates (51/61%) aerolysine positive (aerA+) and 23 isolates (74/19%) for cytolytic enterotoxin gene (act+) were positive. The result of present study showed that most of the confirmed isolates genotype was hlyA+ act- with frequency equal to 51/61%. For investigating the protection effect of acut strain of bacteria, UV inactivated bacterin was used

The effect of vitamins E, C and selenium as stimulants of the immune system on blood factors, growth and immunity of Asian cates (Lates calcarifer)

ABSTRACT This study was performed to evaluate the effect of immune system stimulants (vitamins E, C and selenium) on biochemical and immunity indices of Late calcarifer. For this purpose, two treatments were selected. Treatment 1 or control group was fed with food without immune stimulant and treatment 2 with diet containing vitamins E, C and selenium at 2% of the biomass weight. Finally, growth efficiency indices were compared in two treatments. Results showed final weight of the control and treatment groups was 761.33 ± 35.8 g and 850.00 ± 5.77 g, respectively. The specific growth rate of the control and treatment groups was 1.3 ± 0.02 and 1.35 ± 0.01 but the feed conversion ratio did not show a significant difference. Hemoglobin and erythrocytes showed a significant increase compared to the control in treatments containing immune stimulants and supplementation (p < 0.05). White blood cells ranged from 41417 ± 2964.84 in the treatment to 42500 ± 683.13 in the control treatment. The number of red blood cells in the control treatment was 2810000 ± 19.1763 and the recipient treatment was 3951667 ± 14588.84. Immune system stimulants including vitamins E, C and selenium can play a role in improving the growth, blood, biochemical and safety indices of farmed Late calcarifer

Evaluation of the immunity factors (THC, TPP, PO, SOD, POD) of shrimp fed with the yeast Saccharomyces cerevisiae compared to shrimp fed without yeast

Effects of S. cerevisiae on immune parameters of the L. vannamei after 14 days of S .cerevisiae feeding were evaluated in this study. For this purpose a total of 300 pieces of shrimp with an average weight of 30 to 35 grams were selected from a pool shrimp Abadan CHOEBDEH. After making sure the health, absence of necrosis on the surface of the body, cuts antenna, shrimp were transferred to the center of BANDAR IMAM Research Station. Adaptation was carried out for 3-5 days. After the adaptation, shrimps were screened for virus (WSSV, TSV, MBV, HPV, YHV, BP, IHHNV and IMNV) and vibrio bacteria. After screening shrimps divided to two groups with three replication (including 50 pieces of shrimp in triplicate). The experimental diet has the commercial shrimp composition, but 2 g of S. cerevisiae substituted 2 g of fish meal. Shrimp of first group (T1) for 14 days with food containing nutritional yeast and shrimp in second group (T2) were fed with normal diet without yeast. After 14 days Immune Factors and survival rates in both groups were evaluated. The results showed that the relative survival rate between the two groups showed no significant difference. But Immune Factors (THC, TPP, PO, POD and SOD) in the treatment fed yeast (T1) compared to control treatment (T2) showed a significant increase. In conclusion these results suggest that the increased survival rate and resistance of shrimp after S. cerevisiae consumption occurs through immune modifications, such as increases in THC, TPP, SOD, SOP and PO activity

Immunization of cultured shrimp against WSSV by use of produced recombinant vaccine (In vitro)

Shrimp diseases, especially viral diseases are the major limiting factors of shrimp farming activities in the world. White spot disease is one of the most pernicious viral disease that lead to serious loss in all shrimps of penaeids family. In Iran during 2002 to 2004 in Khuzestan province and in 2005 in Bushehr province, the most ponds and farms infected with white spot and the entire industry faced threat of closure. Surface proteins of virus has important role in the early stages of virus with host cell interaction, because these proteins usually enumerated as a candidate to produce a subunit and recombinant vaccines. On the other hand, these proteins can use as an important virus antigen and produce virus-specific antibodies in the preparation of diagnostic kits. In several studies proteins in the form of injection or oral vaccine has shown promising results. This study was designed in order to gain these proteins for immunization of white leg shrimp. To achieve the white spot virus genome, sampling and DNA extraction of moribund shrimps with clinical signs was done from Choebdeh farms. VP28 and VP19 protein-coding gene-specific primers were selected, and after amplification and purification were cloned in E.coli TG1. Protein expression evaluated and commercial plates were coated with inactivated bacteria containing the recombinant protein. White leg shrimp post larvae (PL30) were fed with recombinant food for 7 days then two times in 9th and 23th day after beginning of plate feeding and was challenged by white spot disease virus. The results of the first exposure (end of the seventh day after the shrimp fed with recombinant plate) showed that the lowest mortality at day 14 after exposure in different groups belong to VP28 group with cumulative mortality percent %30 ± 3.84 and the highest percentage of the Group TG1 equal to %72.22±2.93, also The highest and lowest relative percent survival, belong to the group of VP28 (60.29± 5.09%) and TG1 (4.41 ± 2.94%), respectively. In terms of mortality percent and relative percent survival, VP28 and VP 28+19 has significant difference with other groups while there was no significant difference between the groups VP19, TG1 and pMal. In the second exposure experiment (21 days after end of plate feeding) results showed that the lowest cumulative mortality in different groups belong to VP28 (%50 ± 5.09) and the highest percentage was owned by Group TG1 equal to %75.55±2.22, also the highest and the lowest of relative percent survival belong to VP28 (%32.86± 6.83) and TG1 (%0.00 ± 2.98) groups respectively. Similar to the first experiment, VP28 showed significant differences in cumulative mortality and relative percentage of survival in contrast to other group. As a general conclusion it can be noted that recombinant protein VP28 in any form that delivered to shrimp was able to protect shrimp against white spot virus. On the contrary VP19 has no this ability. The survival rate is directly related to the duration of the presence of recombinant protein in the diet

Identification of WSSV, TSV & IHHNV in wild and cultured shrimps and crustaceans in Khuzestan province - Abadan and investigation of its pathogenicity

According to the white spot disease during 2002 until 2005 and the damages caused by the disease to the farmers a new species L.vannamei were introduced to the farming region of Abadan Choebdeh from 2006. Hight mortality occurred in Khuzestan province farms in 2007 and 2008 again. Probably viral agent was transferred to native shrimps or other aquatic animals, therefore it is very important that presence of viruses in local aquatic animals and its vectors detected. Detection of WSSV, TSVand IHHNV in aquatic animal from Khuzestan costal region imphasis to wild shrimp and craps is the main objectives of this study. So samples were taken from 10 active farms twice a week and 100 postlarves from 3 active breeding center befor stocking. Samples for viral detection were studied by molecular and histopathology asseys. Results was shown presence of the White spot virus in cultured and wild shrimp and TSV infection in only two cultured shrimps but there was negative result for IHHN virus. To study the pathogenesis of white spot virus isolated from wild and farmed shrimps, exposure method was used. Results of challenge showed that WSSV can be transmited from diseased cultured and wild shrimp to cultured shrimp. Mean mortality percent in the treatment that fed with infected wild shrimp was 38.33±10.4 and treatment that fed with infected cultured shrimp 61.66±7.63 and in the positive control treatment was 87.5±3.5

Carbapenem resistance in Bacteroides fragilis: A review of molecular mechanisms

Carbapenems are an applicable subclass of b-lactam drugs in the antibiotic therapy of anaerobic in-fections, especially for poly-microbial cases, due to their broad antimicrobial spectrum on aerobic and anaerobic bacteria. Bacteroides fragilis is the most commonly recovered anaerobic bacteria in the clinical laboratories from mono-and poly-microbial infections. B. fragilis is relatively non-susceptible to different antibiotics, including b-lactams, tetracyclines, fluoroquinolones, and macrolides. Carbapenems are among the most effective drugs against B. fragilis strains with high-level resistance to different antibi-otics. Increased antibiotic resistance of B. fragilis strains has been reported following the overuse of an antimicrobial agent. Earlier contact with carbapenems is linked with increased resistance to them that limits the options for treatment of B. fragilis caused infections, especially in cases caused by multidrug-resistant strains. Several molecular mechanisms of resistance to carbapenems have been described for different carbapenem-resistant bacteria. Understanding the mechanisms of resistance to antimicrobial agents is necessary for selecting alternative antimicrobial agents and the application of control strategies. In the present study, we reviewed the mechanisms contributing to resistance to carbapenems in B. fragilis strains. (C) 2022 Elsevier Ltd. All rights reserved

Digestive function and serum biochemical parameters of juvenile Cyprinus carpio in response to substitution of dietary soybean meal with sesame seed (Sesamum indicum) cake

A feeding trial was designed to evaluate effects of soybean meal replacement (SBM) with sesame seed cake (SSC) at 0 (SSC0), 25 (SSC25), 50 (SSC50), 75 (SSC75), and 100 (SSC100) % in isoproteic (30%) and isolipidic (8%) diets on the growth performance, digestive function and serum and hematological parameters in Cyprinus carpio. Four hundred and fifty common carp juveniles (83.09 g) were randomly distributed into 15 tanks with a flow-through system. Triplicate groups of fish were hand-fed one of the diets to visual satiation thrice daily for 90 days. The survival rate, growth performance and somatic indices did not show significant differences between treatments. Among feed utilization indicators, nitrogen retention efficiency was significantly higher in SSC25 than in other treatments. Lipid retention efficiency significantly increased from SSC50 to SSC100. The number of white blood cells was significantly higher in SSC0 than other treatments. Significantly higher hemoglobin was observed in SSC75 as compared to SS0 and SSC25. Serum biochemical parameters did not significantly differ between dietary treatments. Dietary SSC resulted in significant increase in calcium ADC and activity of digestive trypsin, chymotrypsin, lipase, α-amylase, and alkaline phosphatase. Significantly higher villi height and intestinal muscle layer width were observed in fish fed the SSC75 diet. The villi width in SSC25 and SSC50 was significantly less than in SSC0. Comparable growth performance, feed utilization, apparent digestibility, digestive function, hematological and serum factors indicated the possibility of 75–100% substitution of SBM by SSC in the diet of juvenile C. carpio