This study aimed to isolate Pseudomonas aeruginosa from cattle (bovine) milk with mastitis to characterize its antimicrobial susceptibility against some antibiotics, and to identify aminoglycoside acetyltransferase (aac-3-Ib) gene.A total of 100 bovine milk samples were collected randomly from different local cow farms at districts of Wasit governorate, Iraq. Six P. aeruginosa isolates were obtained using bacterial culture method and further identified by Analytical Profile Index (API-20E). The antibiotic sensitivity test was performed by disc diffusion methods. Among the 5 antibiotics used, the highest resistance (100%) was found with Nalidixic acid andtetracycline, follow by gentamicin (50%) and the lowest resistance rate (16.6%, and 33.3%) was to the ciprofloxacin and cephalothin respectively. PCR was performed for all the gentamicin resistant isolates that be among the aminoglycoside family. The where the frequency of aac(3)-Ib gene have product (530bp) was to 3 of P. aeruginosa isolates. From the finding of present study we concluded that P.aeruginosa thatisolated from mastitic bovinehave been developed resistance against aminoglycosides through presence of aac(3)-Ibgene and the ciprofloxacin and cephalothin can be taken as good choice of treatment

Citrobacter freundii (C. freundii) is responsible for a number of significant opportunistic infections. The present research was aimed to estimate the immune response of rabbits immunized with whole cell sonicated antigen (WCSA), lipopolysaccharide (LPS), and DNA antigens (Ag) extracted from C. freundii. Twenty-four Albino rabbits of both sexes, with 2-3 kg body weight, were divided randomly into four groups (6 rabbits for each). Two types of tests were performed including ELISA and skin test (delayed type hypersensitivity, DTH)). The 1st group was immunized with WCSA (1000 μg/mL). The 2nd group was immunized with LPS Ag at the same dose. The 3rd group was immunized with DNA extracted Ag (0.083 μg/mL). The 4th group (negative control) was injected with 1 mL PBS (pH 7.2) subcutaneously. After 14 days, rabbits were given booster doses of same Ag. The immunized animals showed significant increase of IgG and IL-6 concentration (P<0.05) following 28, 32, 46, 50 and 60 days of immunization in comparison with the negative control group. Concerning DTH, it showed an increase in the means of induration and erythema, with significant differences (P˂0.05) exerted by the concentrated antigens in all immunized groups after 24 h and 48 h compared with diluted Ag and negative control group. In conclusion, WCSA and LPS Ag, in comparison to DNA Ag, were observed to promote stronger humoral (IgG) and cellular (DTH and IL-6) immune responses. DNA Ag, on the other hand, elicited a weaker humoral and cellular immune response than other Ag.

Antigens prepared from sonicated Salmonella typhimurium (KWCSA-ST) and Lactobacillus acidophilus (KWCSA-LBA) were used to evaluate synergistic effect on interlukine production (IL-2, IL-4) and Immunoglobulin-G (IgG) which were evaluated by using Enzyme Linked Immunosorbent Assay and Delayed Type Hypersensitivity-skin test at day 20 post  immunization. Twenty five rabbits of both sexes, 2-3 Kg body weight, were divided into five equal groups; the first group immunized by KWCSA-ST (1000 µg/ml) and KWCSA-LBA (1000 µg/ml), the second group by KWCSA-ST (1000 µg/ml) and KWCSA-LBA (500 µg/ml), the third group by KWCSA-ST (1000 µg/ml) as positive control, the fourth group by KWCSA-LBA (1000 µg/ml) as positive control and the fifth group was injected by P.B.S. (pH7.2) as negative control group subcutaneously. The result of delayed type hypersensitivity showed an increase in the means of erythema and induration in the 1st group after 24hrs and 48hrs while the 4th group recorded the lowest mean after 24hrs and 48hrs. These means showed significant differences (P˂0.05) compared with injection by 1:2 and 1:4 diluted Ag. While the results of IgG showed that the highest concentration was at 35th day in the first group while the lowest concentration at 35th day in the fourth group with significant differences (P<0.05). Also the high concentration of IL-2, IL-4 was recorded in the first group at 35th day and the lowest concentration was in the fourth group at 35th day with significant differences (P<0.05); also the results showed significant differences (P<0.05) between the 1st, 2nd, 3rd compared with 4th and 5th groups.

     This study was designed to evaluate the levels of interleukins (2, 6 and 8) in immunized white  rats by killed whole cell antigens of Salmonella enterica subspecies typhimurium and sonicated Cryptococcus neoformans, and using  ELISA in day 10, 20, 30, 40 and 50 after immunization one hundred white rats of both sexes divided into five groups (20 rats for each). The first group was immunized by killed whole cell antigens of Salmonella enterica subspecies typhimurium (9× 108 CFU /ml) and sonicated Cryptococcus neoformans (1000 µg/ml), The second was immunized by killed whole cell antigens of Salmonella enterica subspecies typhimurium (9× 108 CFU /ml) and sonicated Cryptococcus neoformans (500 µg/ml). The third was immunized by killed whole cell antigens of Salmonella enterica subspecies typhimurium (9× 108 CFU /ml) as positive control group, The fourth was injected 1 ml of phosphate buffer saline (pH 7.2) as control negative group and fifth was immunized by sonicated antigens of Cryptococcus neoformans (1000 µg/ml). The results of IL-2 showed significant differences (P<0.05) between the 1st, 2nd and 3th groups compared with 4th and 5th group, while there was no significant difference (P≥0.05) between 4th and 5th groups. Also IL-6 showed that there were significant differences (P<0.05) between the 1st, 2nd and 3rd groups in comparison with 4th group, while there was no significant difference (P≥0.05) between the 1st, 2nd, 3rd groups and 5th group. In the IL-8 showed that there was a significant difference (P<0.01) between the1st and 2nd groups and between 3rd group and 1st and 2nd groups without significant difference (P≥0.05), also between the 1st, 2nd and 3rd groups and 4th group significant difference (P<0.05) and with a significant difference (P<0.01) between 5th group and all other groups (1st, 2nd, 3rd and 4th).