Date of Award

11-2019

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Food Science

First Advisor

Dr. Mutamed Ayyash

Second Advisor

Dr. Aisha Abushelaibi

Abstract

Seafood and fish are important food components for a large section of the world population. Seafood is prone to bacterial contamination, many are pathogenic to human and marine animals, and three species, Vibrio mimicus, Vibrio parahaemolyticus, and Vibrio vulnificus, are responsible for most cases of seafood-related human illness caused by Vibrio species. The study on the prevalence of these microorganisms in seafood of the United Arab Emirates is vital due to the cultural background of the Emiratis as a coastal heritage. A study was conducted to assess the prevalence of Vibrio spp. in imported fishes from local markets, identify the Vibrio spp., examine the antimicrobial resistance, and profile growth conditions of the isolated Vibrio. In the present study, 200 fish samples were collected from four different main markets in four cities (Al-Ain, Dubai, Fujairah, and Abu Dhabi) in the United Arab Emirates. Vibrio spp. were isolated from the collected fish samples and identified by the standard culture method. DNA was extracted from all the isolates and used for molecular characterization by Polymerase Chain Reaction (PCR). The antibiotic study was also performed to find out the resistance and sensitivity of the Vibrio species. The factors affecting the growth rate and survival of the isolated Vibrio spp. were studied by analyzing the effect of different parameters such as temperature, pH, and salinity. Results showed that V. paraheamolyticus was predominant in the isolates. The presence of Vibrio spp. was confirmed in 129 (64.5%) of the 200 isolates collected from different cities. The isolates from Al-Ain showed an occurrence of 1 (2%) for Vibrio mimicus and were 3 (6%) for each of V. vulnificus and V. paraheamolyticus. An occurrence of 5 (10%) for V. paraheamolyticus, V. mimicus, and V. vulnificus was not detected in isolates from Dubai. Vibrio isolates from Fujairah showed an occurrence of 4 (8%) for V. vulnificus and V. paraheamolyticus, 2 (4%) for V. mimicus. The prevalence of Vibrio in isolates from Abu Dhabi was 3% for V. vulnificus and V. paraheamolyticus and 0% for V. mimicus. The antibiotic sensitivity of the isolates was evaluated by measuring the zone of inhibition against 6 common antimicrobial agents. Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio mimicus isolates were resistant to penicillin G, daptomycin, vancomycin, ampicillin, and erythromycin while all the three Vibrio spp. were susceptible to sulfamethoxazole-trimethoprim. The effect of various parameters such as temperature, pH, and salinity on growth and survival of Vibrio isolates showed Vibrio parahaemolyticus, Vibrio vulnificus and Vibrio mimicus isolates exhibited maximum growth rate at 37°C while increasing the temperature to 47°C the growth percentage was decreased. The three Vibrio spp. were grown significantly at alkaline pH (pH 5 and 7). Increasing the concentration of NaCl from 0.5% to 2%, the growth rate of Vibrio isolates was increased and the optimum growth rate was shown in 1% NaCl. From the results, we can conclude that the Vibrio isolates from different cities of UAE showed antibiotic resistance and it is a threat to public health as the antibiotic-resistant determinacies transferred to other bacteria of clinical significance.

Comments

تم العثور على المأكولات البحریة والأسماك لتكون عنصرا غذائیا ھاما لقطاع كبیر من سكان العالم. الأطعمة البحریة عرضة للتلوث الجرثومي، والعدید منھا مُمْرِض للبشر و المخلوقات البحریة، و تم العثور على ثلاثة أنواع ھي Vibrio و Vibrio mimicus ،Vibrio vulnificus و parahaemolyticus ھي المسؤولة عن معظم حالات الأمراض البشریة المرتبطة بالمأكولات البحریة التي تسببھا أنواع بكتیریا الڤیبریو . أھمیة دراسة آثار ھذه الكائنات الحیة الدقیقة على البشر في دولة الإمارات العربیة المتحدة أمر حیوي بسبب الخلفیة الثقافیة للإماراتیین كتراث ساحلي. تم إجراء دراسة لتقییم مدى انتشار بكتیریا الڤیبریو في الأسماك والمنتجات السمكیة التي تباع في دولة الإمارات العربیة المتحدة، وتحدید محیط البكتیریا، ودراسة مدى حساسیة مضادات المیكروبات وظروف نمو الڤیبریو المعزولة. تم جمع 200 عینة سمكیة من 4 أسواق رئیسیة مختلفة في مختلف الإمارات (العین ودبي والفجیرة وأبو ظبي) في الإمارات العربیة المتحدة. بكتیریا الڤیبري تم عزلھم من عینات الأسماك التي تم جمعھا والتي تم تحدیدھا بواسطة طریقة الاستزراع القیاسیة. تم استخراج الحمض النووي من جمیع العزلات واستخدم للتوصیف الجزیئي بواسطة تفاعل البلمرة المتسلسل (PCR) كما تم إجراء دراسة المضادات الحیویة لمعرفة مقاومة وحساسیة أنواع البكتیریا .

تمت دراسة العوامل التي تؤثر على معدل النمو والبقاء على بكتیریا الڤیبریوالمعزولة من خلال تحلیل تأثیر المعلمات المختلفة مثل درجة الحرارة، ودرجة الحموضة والملوحة. أظھرت النتائج أن parahaemolyticus كان سائدا في العزلات. أظھرت العزلات من العین حدوث 1 (2%) الـ Vibrio mimicus وكانت 3 ( %6 ) لكل من V.vulnificu و .V.paraheamolyticus. كما لوحظ حدوث 5(%10) لـ V.paraheamolyticus ولـ V.mimicusو V. vulnificus في عزلات من دبي.

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