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التحري عن بعض عوامل الضراوة للزائفة الزنجارية المعزولة من الحليب الخام والجبن الطري == Detection of Some Virulence Factors of Pseudomonas Aeruginosa Isolated From Raw Milk And Soft Cheese
Author name:
عبد الكریم كاظم عبد الحسین الحسب
Supervisor name:
علي حسن احمد الشمري
General topic:
Veterinary Medicine
Specific topic:
Food Hygiene
Degree:
Master
University:
University of Baghdad - College Of Veterinary Medicine
Language:
English
University location:
Baghdad
First pages:
21T496 - p.pdf
Abstract:
In order to detection of Pseudomonas aeruginosa in food - chain especially from Cows raw milk and soft cheese with its whey, this study was designed in some regions of Baghdad (College of Veterinary Medicine, Abu - Ghraib, Al - Sadrya & Al - Radwaniyah), in which a standard isolation methods were used with some modification processing by new, modern and rapid technology tools such as chromogenic medium CNP agar and Electronic rapid Microbact TM 24E panel identification system supported by standard color differential chart and online American Type Culture Collection (ATCC) Codes; aids in rapid and precise identification, differentiation, confirmation and enumeration of P. aeruginosa isolates from raw dairy samples; as well as, detection of biofilm producing versatile morphotypes with chameleon phenomenon and fruity odour; and demonstration the activity of food spoilage enzymes (protease, lipase & lecithinase) of isolates with thermo - stability and viability in different temperatures with bitty cream and ropy fermentation phenomenon. The results profile showed : 1. Isolation of 46 (76.7%) isolate of P. aeruginosa from a total of 60 Cow Dairy samples : 30 Raw Milk samples (pooled from milk cans and apparently healthy Cows with a history of mastitis cases) as 19 (31.7%) isolates from regions of College of Veterinary Medicine, Abu - Ghraib and Al - Sadrya (10 from each region); and 30 Soft Cheese with its Whey samples (pooled from unhygienic processed cheese and containers in unclean dirty environment and apparently carrier or diseased workers) as 27 (45%) isolates from regions of Abu - Ghraib, Al - Sadrya and Al - Radwaniyah (10 from each region). Isolation percentages of oxidase positive P. aeruginosa from selected Regions in Baghdad Province indicates significant differences among regions at a level (P?0.05), in which highest isolation percent of P. aeruginosa from Abu - Ghraib as 20 (33.4%) isolates (10 isolates from raw milk and 10 isolates from soft cheese) in accordance to 17 (28.4%) isolates from Al - Sadrya (9 isolates from raw milk and 8 isolates from soft cheese), 9 (15%)SUMMARYisolates from Al - Radwaniyah (9 isolates from soft cheese) without any isolate from College of Veterinary Medicine, which may indicate good hygienic measurements.2. Segregation of isolates into two Haemolytic Patterns : Livestock type origin, lysis only sheep blood (L - type) as 19 (41.30%) isolates from raw milk samples; and Zoonotic type lysis, both blood (Z - type) as 27 (58.70%) isolates from soft cheese with its whey as high prevalence due to critical processing chain, risky carrier individuals and contaminated environment or polluted water supply. This may indicate indirectly genetic diversity and host or cross individual tropism in haemolysins - phospholipases activity according to different types of samples, regions and hosts.3. The study revealed isolation and segregation of versatile morphotypes and five pigments with fruity odor (Chameleon phenomenon) with mucoid drippy due to alginate or small colonial variants smooth or rough or both especially in isolate code M7 from mastitic milk and isolate code C27 from contaminated soft cheese and its whey. Wrinkled - Corroded green morphotypes were more evident in blood agar due to secretion of siderophore pyoverdine in order to chelating iron for activation of isolate. Motility Pattern with TTC salts was evident in all isolates with three types of motility : swarming, swimming and twitching, that noticed obviously in M7 isolate.4. New technology biochemical identification panel system (Microbact TM 24E) confirm that isolates were P. aeruginosa at level (P?0.01) after online matching with standard Remel ATCC Octalcodes bank of P. aeruginosa, in which 5 octalcodes typical and atypical were documented, that indicate genetic diversity in biochemical reactions of isolates and their morphotypes, modified microbial gene sharing protocol of P. aeruginosa with other bacteria and highly Sensitivity and Specificity of the test panel.SUMMARY5. Detection and isolation of Biofilm producing isolates by five methods, in which microtiter plate assay was the most sensitive and realizable technique while Congo red agar test detect quantity and type of biofilm production through colour of colonies (black very strong and huge, gray strong, pink moderate and white fair or non - producer). Biofilm produced in most morphotypes with pellicles at liquid interphase and ropy viscous threads (sliminess) and bitty cream especially in isolate codes M7 and C27. Small colonial variants of some morphotypes can revert to mucoid drippy variants. M7 showed unusual ropy thread of 30 cm long.6. The results showed secretion of thermo and psychro stable and labile food spoilage enzymes (protease, lipase and lecithinase) from isolates, in which versatile morphotypes showed indirectly diverse genetic ability, this may indicate variation of thermal tolerance mechanisms (heat shock proteins and biofilms formation) in isolates in accordance to time and temperature of processing, that linked genetically with the quorum sense mechanisms of acyl homoserine lactone gene regulatory region (AHL) in P. aeruginosa isolates (Stress Hardening phenomenon).7. The results showed the genetic ability (indirectly) of some isolates to resist, tolerate and proliferate in acidic environment at pH 2 & 4 especially isolate M7 & C27, while intermediate to susceptible tolerance of pH were noticed in others. This may indicate the power of electromagnetic charged net field of complex polymeric matrix of alginate exopolysaccharide layers in protecting some isolates from adverse acidic environment due to quorum sensing behavior of M7 & C27.Therefore, it could be concluded from this study that P. aeruginosa was prevalent in food chain especially from Cows raw milk and soft cheese with its whey samples from some regions in Baghdad, and Biofilm producing isolates with their thermo and psychro stable enzymes complex system and their tolerance to acidic environment stressors were more dangerous thus, we recommend monitoring these products periodically for insurance of public health.
