Identification Of Pathogenic Bacteria Research Articles

Early detection and classification of live bacteria using time-lapse coherent imaging and deep learning

Early identification of pathogenic bacteria in food, water, and bodily fluids is very important and yet challenging, owing to sample complexities and large sample volumes that need to be rapidly screened. Existing screening methods based on plate counting or molecular analysis present various tradeoffs with regard to the detection time, accuracy/sensitivity, cost, and sample preparation complexity. Here, we present a computational live bacteria detection system that periodically captures coherent microscopy images of bacterial growth inside a 60-mm-diameter agar plate and analyses these time-lapsed holograms using deep neural networks for the rapid detection of bacterial growth and the classification of the corresponding species. The performance of our system was demonstrated by the rapid detection of Escherichia coli and total coliform bacteria (i.e., Klebsiella aerogenes and Klebsiella pneumoniae subsp. pneumoniae) in water samples, shortening the detection time by >12 h compared to the Environmental Protection Agency (EPA)-approved methods. Using the preincubation of samples in growth media, our system achieved a limit of detection (LOD) of ~1 colony forming unit (CFU)/L in ≤9 h of total test time. This platform is highly cost-effective (~$0.6/test) and has high-throughput with a scanning speed of 24 cm2/min over the entire plate surface, making it highly suitable for integration with the existing methods currently used for bacteria detection on agar plates. Powered by deep learning, this automated and cost-effective live bacteria detection platform can be transformative for a wide range of applications in microbiology by significantly reducing the detection time and automating the identification of colonies without labelling or the need for an expert.

Isolation and Identification of Pathogenic Bacteria from Soil Mixed with Hospital Wastes

Objective: Hospital solid wastes when not incinerated (nor waste-waters are scientifically treated) remain as sources of a myriad of pathogenic microorganisms. Methods: A total of 960 waste samples (soil mixed with waste) were collected from waste disposal site of the hospital. After successful growth, bacteria were sub-cultured in nutrient agar slants for preservation. Biochemical characteristics of isolated bacteria were done for identification of bacteria. Results: A total of 150 collected waste soil samples yielded 103 bacterial colonies, as 65 single and 38 mixed colonies, while 47 samples had no microbial growth. Methicillin resistant S. aureus (MRSA), vancomycin resistant enterococci (VRE) and Pseudomonas aeruginosa isolates were in numbers, 28, 19 and 18, respectively. Of 103 colonies, 63 and 40 were from wastes of wards and ICUs. Invariably, MRSA strains were isolated, as single or mixed colonies. The average minimum inhibitory concentration (MIC) range against oxacillin was recorded as 16 ?g/mL for MRSA, and Vancomycin 16 ?g/mL for VRE and 8 ?g/ mL gentamicin for P. aeruginosa. Conclusions: Site specific variation and seasonal variations underplay prevalence of different types of nosocomial spread of opportunistic pathogenic bacteria.

Development of a DNA microarray assay for rapid detection of fifteen bacterial pathogens in pneumonia

BackgroundThe rapid identification of pathogenic bacteria is important for determining an appropriate antimicrobial therapy for pneumonia, but traditional bacterial culture is time-consuming and labourious. The aim of this study was to develop and evaluate a DNA microarray assay for the simultaneous detection of fifteen bacterial species directly from respiratory tract specimens in patients with pneumonia. These species included Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Mycoplasma pneumoniae, Enterococcus faecalis, Enterococcus faecium, Enterobacter cloacae, Stenotrophomonas maltophilia, Burkholderia cepacia, Legionella pneumophila and Chlamydia pneumoniae. The 16S rDNA genes and other specific genes of each pathogen were chosen as the amplification targets, amplified via multiplex polymerase chain reaction (PCR), and hybridized to oligonucleotide probes in a microarray.ResultsThe DNA microarray detection limit was 103 copies/μL. Nineteen standard strains and 119 clinical isolates were correctly detected with our microarray, and 3 nontarget species from 4 clinical isolates were not detected. Additionally, bacterial pathogens were accurately identified when two or three bacterial targets were mixed together. Furthermore, the results for 99.4% (156/157) of clinical specimens were the same as those from a conventional assay.ConclusionsWe developed a DNA microarray that could simultaneously detect various bacterial pathogens in pneumonia. The method described here has the potential to provide considerable labour and time savings due to its ability to screen for 15 bacterial pathogens simultaneously.

Identification of Pathogenic Bacteria on Carp Commodities (Cyprinus carpio) at Quality Control and Fishery Product Safety Agency (BKIPM) of Bengkulu

Carp (Cyprinus carpio) is a type of freshwater fish that is widely cultivated. The increase in the amount of production and trade in freshwater fishery commodities both for consumption in Bengkulu will potentially increase the risk of entry and spread of pests and diseases in fish, which at the same time will be a threat that can endanger and damage the sustainability of fishery biological resources. Bacteria that infect fish can inhibit the expected production targets, which is an outbreak of pathogenic fish disease caused by bacteria. This study aims to identify pathogenic bacteria that infect Carp (C. carpio). Carp were obtained from fish traders at Panorama Market, Bengkulu City. Carp samples were selected based on clinical symptoms that were no longer healthy. Isolation of bacteria from Carp’s organs using Triptic Soy Agar (TSA) media. The isolates were screened by morphological characters and biochemical test. The results of this study showed that total of 2 bacteria were isolated. Based on biochemical tests carried out such as the Simmons Citrate test, Triple Sugar Iron Agar, Oxidative-Fermentative, Motility Indol Ornithine, Lysine Iron Agar, MR-VP, urea, catalase, oxidase, gelatin, confectionery test, and Rimmler-Shotts test, pathogenic isolates Sp 1. in the sample have a close relationship with Plesiomonas shigelloides while the pathogenic isolates Sp 2. and Sp 3. have a close relationship with Aeromonas hydrophila.

Bacterian Species Identification from Raw Cow Milk Sample – A Case Study

The raw milk can support a wide variety of microbiota, due to its high nutritional content. These microorganisms become from a variety of sources and in farm animals and can cause serious damage by infecting the mammary glands and causing mastitis. The mastitic milk is an important source of disease among the consumers. In this paper, we present a study case of pathogenic bacteria identification by DNA based methods from raw milk samples which were collected from farm cows with severe recurrent mastitis. Previously it was diagnosticated that multidrug resistant bacteria E. coli strains are causing those infections. The laboratory procedure consisted of isolation of DNA from raw cow milk samples, followed by PCR based bacterial identification and DNA sequencing. Data collected from sequencing experiment were aligned against reference sequences from bacterial strains. In our study it was found that Pseudomonas aeruginosa, is present in the mastitic milk samples.

KARAKTERISASI BAKTERI PATOGEN PENYEBAB LAYU PADA TANAMAN BAWANG MERAH (Allium ascalonicum L.)

Shallot (Allium ascalonicum L.) is one of the vegetable commodities in the form of tubers that have a high economic value. The development of shallot cultivation in Indonesia often experiences obstacles, one of which is an obstacle in the process of shallot cultivation, namely the attack of Plant Disturbing Organisms (OPT). Information about diseases caused by pathogenic bacteria is still very limited. This study aims to determine the symptoms and identification of pathogenic bacteria that cause wilt in shallots. Bacterial isolation was carried out using Nutrient Agar (NA) media and 36 bacterial isolates were collected from shallots. Bacterial isolates were then tested for pathogenicity to determine the ability of bacteria to cause wilt disease in shallots. The results of isolation obtained 10 bacterial isolates that can show symptoms on red onions namely wilted leaves, yellow and soft rotten tubers. Four isolates including positive can show hypersensitivity symptoms, namely M11, N20, N17 and N14. Based on the identification of bacteria in physiology showed 2 groups of different isolates. Biochemical test results of Isolate M11, N20 and show species suspected of B. cepacia. N3 and N14 isolates are suspected to be E. carotavora subsp. carotavora. The bacterial isolates N7, N17, P5 and P7 were suspected to be E. carotavora subsp. betavasculorum. The isolate of N4 bacteria is suspected to be E. cacticida.

Identification of Pathogenic Bacteria from Diseased Thai Pangas Pangasius hypophthalmus with Their Sensitivity to Antibiotics

Thai Pangas (Pangasiaus hypophthalmus) has been emerging as an economically very important species due their faster growth, year round production and high productivity in South-East Asian aquaculture. It has good market value as a food fish due to its good taste and deliciousness with high protein, minerals and fat content. It is also popular as a game fish.
 Aims: The present study was conducted to identify bacterial pathogens in diseased P. hypophthalmus and evaluate their sensitivity to antibiotics.
 Methodology: To identify the causativeagent of diseased fish pure culture of bacteria using slant and streak plate techniques and different biochemical tests such as Gram’s Staining, Motility Test, Sugar Fermentation Test, MR-VP test, Indole Test etc. were performed. To assess the sensitivity of the isolated bacteria to antibiotics five antibiotics disks i.e. Ciprofloxacin (5μg), Azithromycin (15μg), Ampicillin/Sulbactam (20μg), Tetracycline (30μg) and Erythromycin (15μg) were used.
 Results: Three pathogenic bacteria i.e. Aeromonas hydrophila, Edwardsiella ictaluri and Pseudomonas sp. were identified in the studied diseased fish. Only Pseudomonas sp. were identified from Fresh fish. E. ictaluri was found only in diseased pangas which was the causative agent for thedisease, Bacillary Necrosis. The results of the antibiotic sensitivity test showed multi-resistances of the identified bacteria to the tested antibiotics. The identified bacteria were 100% sensitive to Ciprofloxacin (5μg), intermediate to Azithromycin (15μg) and Tetracycline (30μg), but resistant to Erythromycin (15μg) and Ampicilin/Sulbactam (20μg).
 Conclusion: Ciprofloxacin (5µg) could be used to control bacillary necrosis disease in Thai pangas. The results of this study will be helpful to the fish farmers for the management of bacterial diseases in fish.

Sugar-metabolism-triggered pathogenic bacteria identification based on pH-sensitive fluorescent carbon dots

Rapid distinguishing of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) with high sensitivity is critical for human health. Herein, a smart sugar-metabolism-triggered E. coli and S. aureus identification strategy is established on the basis of pH-sensitive fluorescent carbon dots (p-CDs). The fluorescence of the prepared p-CDs depends linearly on the solution pH in the acidic range from 4.0 to 7.0. When p-CDs are introduced into aqueous solutions that contain bacteria and sugar molecules, such as glucose or lactose, the fluorescence readout is reduced due to the acidic substances that are produced in the glucometabolic process of bacteria toward sugar molecules, which can decrease the pH of the sensing system. More importantly, E. coli and S. aureus differ in terms of their sugar metabolic capability on lactose and thus can lead to distinguishable fluorescence signals, which are used to further distinguish E. coli from S. aureus. The detection limits (LODs) for E. coli and S. aureus are 21 CFU mL-1 and 33 CFU mL-1, respectively, in the presence of glucose and 762 CFU mL-1 for E. coli in the presence of lactose. This p-CD-based fluorescence approach is simple, sensitive and free of any modification steps; thus, it has a much broader field of potential applications than other approaches.

ASSESSMENT OF BACTERIAL CONTAMINATION LEVELS ON THE SURFACE OF THE BOVINE CARCASSES AT SLAUGHTERHOUSES OF BARISHAL CITY IN BANGLADESH

Background: Meat industries in developing countries including Bangladesh are found to be challenged by severe hygienic and sanitation problems which are associated with heavy bacterial load on the different sites of carcasses and meat. Objectives: The major objectives of this study were to determine the bacterial load at the different risk sites of bovine carcasses and identification of pathogenic bacteria as well as to assess the associated hygienic and sanitation practices with public health significance of the isolated bacteria. Materials and Methods: The study on bacterial load of bovine carcasses was conducted on 200 swab samples of different risk sites of 20 bovine carcasses in the different slaughterhouses of Barishal City Corporation during the period from April to October 2017. The aseptically collected swab samples from different sites of bovine carcasses were processed and analyzed individually by standard bacteriological procedures for Total viable count (TVC), Total coliform count (TCC), Total Staphylococcus count (TSC) and Total Salmonella count (TSAC) and the bacterial species were identified by the conventional aerobic cultural, morphological and biochemical tests. The hygienic status and practices of slaughterhouses and workers were evaluated through a structured questionnaire survey and also a visual inspection. Results: Staphylococcus aureus (78.5%), Salmonella spp. (64.5%) and Escherichia coli (64.0%) were found widely prevalent bacteria on the surface of freshly slaughtered bovine carcasses. The mean TVC of bacteria at pre-and post-washing of the different risk sites of carcasses including neck, shoulder, rump and their used knife and workers’ hand was calculated and highest one was recorded for neck at both pre (8.17 ± 1.22) and post (8.41 ± 0.92) washings. These TVC were found higher compared to standards set by WHO. The TSC was found highest at shoulder site at both pre (7.26 ± 0.94) and post (7.43 ± 1.02) washing, whereas the neck site was found highest contaminated with E. coli (6.69 ± 1.06 and 6.87 ± 1.04) and Salmonella spp.(5.73 ± 1.05 and 6.07 ± 0.92), respectively. The questionnaire survey and visual inspection of slaughter houses revealed that none of the slaughterhouse workers received any training on slaughterhouses management and hygiene, not used any head and hair covering, protective clothes and hand gloves whereas only 25.33% workers washed their hands and 34.67% used clean water at slaughterhouses during processing of carcasses and meat. Conclusions: The slaughtering of the animals on the ground and then skinning and evisceration in the same place under poor hygienic conditions are the major risk factors for heavy bacterial contamination of carcasses which has been recognized as a threat to food safety and consumers health to foodborne illness. Therefore, it requires a serious attention from all relevant authorities to apply and maintain the basic hygienic slaughterhouse practices to prevent the bacterial contamination of carcasses to prevent food borne illness. However, these data should serve as a baseline for future comparisons in measuring the bacteriological status of beef carcasses in other districts and further research works.

Isolation and Identification of Pathogenic Bacteria from Vaginal Cavity of Sheep and Goats in Iraq

Isolation and Identification of Pathogenic Bacteria from Vaginal Cavity of Sheep and Goats in Iraq

Online Concentration of Bacteria from Tens of Microliter Sample Volumes in Roughened Fused Silica Capillary with Subsequent Analysis by Capillary Electrophoresis and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry.

This study presents a timely, reliable, and sensitive method for identification of pathogenic bacteria in clinical samples based on a combination of capillary electrophoresis with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. In this respect, a part of a single-piece fused silica capillary was etched with supercritical water with the aim of using it for static or dynamic cell-surface adhesion from tens of microliter sample volumes. The conditions for this procedure were optimized. Adhered cells of Staphylococcus aureus (methicillin-susceptible or methicillin-resistant) and of Pseudomonas aeruginosa were desorbed and preconcentrated from the rough part of the capillary surface using transient isotachophoretic stacking from a high conductivity model matrix. The charged cells were swep and separated again in micellar electrokinetic chromatography using a nonionogenic surfactant. Static adhesion of the cells onto the roughened part of the capillary is certainly volumetric limited. Dynamic adhesion allows the concentration of bacteria from 100 μL volumes of physiological saline solution, bovine serum, or human blood with the limits of detection at 1.8 × 102, 1.7 × 103, and 1.0 × 103 cells mL-1, respectively. The limits of detection were the same for all three examined bacterial strains. The recovery of the method was about 83% and it was independent of the sample matrix. A combination of capillary electrophoresis with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry required at least 4 × 103 cells mL-1 to obtain reliable results. The calibration plots were linear (R2 = 0.99) and the relative standard deviations of the peak area were at most 2.2%. The adhered bacteria, either individual or in a mixture, were online analyzed by micellar electrokinetic chromatography and then collected from the capillary and off-line analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry without interfering matrix components.

Acute Death of Kangaroos in a Zoo Due to Highly Pathogenic Corynebacterium pseudotuberculosis and Yersinia pseudotuberculosis

Background: “Lumpy jaw” is disease effecting wallabies and kangaroos, particularly in Macropus rufus and Macropus giganteus. In the most serious situations, additional tooth loss and fistulas follow, accompanied by a stench, weight loss, and eventually death due to sepsis or blood poisoning. “Lumpy jaw” disease has seriously affected the normal display and health of kangaroos, and cause a huge economic loss. There was an outbreak of jaw infection in kangaroos at the Nanjing Forest Zoo. Two Macropus giganteus and two Macropus rufus died of “lumpy jaw”. The main objective of the describing case was to isolate pathogens, provide a basis for follow-up treatment, and serve to establish a disease prevention protocol.Case: Four grown-up kangaroos (two Macropus giganteus and two Macropus rufus) were raised in Nanjing Forest Zoo, who had obviously clinical symptoms, such as oral lesions of pus, necrotic tissue, rotting teeth, then died of “lumpy jaw”. Oral swab samples were collected from the lesion sites of the dying kangaroos. Mice experiments were conducted to examine the pathogenicity of the strains. Tests of antimicrobial susceptibity were performed to prescribe with better drug treatments for kangaroos. Corynebacterium pseudotuberculosis and Yersinia pseudotuberculosis were identified based on morphology, culture characteristics and biochemical tests. Corynebacterium pseudotuberculosis (G+) in Sucrose, Mannitol, Lactose, Maltose, Glucose tubes were positive, that acids and gases both production, in Gelatin liquefaction, Indol test, MR were positive, that only acids production, others were negative; Yersinia pseudotuberculosis (G-) in Urea, MR were positive, that only acids production, others were negative.The infected mice presented with gum erosion or ulcers when the two pathogens were injected subcutaneous at the oral regional by 2-3 point at 0.2 mL of individual strains（1.0×109 CFU/mouse）. Drug sensitivity tests showed that Corynebacterium pseudotuberculosis is highly sensitive to Erythromycin (E) and Sulfamethoxazole (SMZ); meanwhile, Yersinia pseudotuberculosis is highly sensitive to Sulfamethoxazole (SMZ), Nitrofurantoin (N), Penicillin-G (P-G) and Erythromycin (E). The other “lumpy jaw” kangaroos in the zoo now receive oral screening with antibiotics (SMZ, E).Discussion: Yersinia pseudotuberculosis is one of three pathogenic bacteria of the gram-negative genus Yersinia; it can be found in birdsand other mammals. It also spreads through soil, plants, and insects in the environment.Yersinia pseudotuberculosis can also lead to fatal systemic symptoms in human. Corynebacterium pseudotuberculosis belongs to the Actinobacteria family, which are associated with Caseous lymphadenitis in breeding animals, especially in goats and sheep. The isolates affected the lymph nodes and visceral organs of the kangaroos in this case, who presented with gingivitis or stomatitis. It is the first report of Corynebacterium pseudotuberculosis and Yersinia pseudotuberculosis co-infecting kangaroo and causing a fatal case of “lumpy jaw” in China. In this case, isolation and identification of pathogenic bacteria were carried out on the sick kangaroos, and animal test and drug susceptibity test were conducted. The study results could provide theoretical basis for the follow-up treatment and prevention method of this disease.

Rapid identification of pathogenic bacteria using Raman spectroscopy and deep learning

Raman optical spectroscopy promises label-free bacterial detection, identification, and antibiotic susceptibility testing in a single step. However, achieving clinically relevant speeds and accuracies remains challenging due to weak Raman signal from bacterial cells and numerous bacterial species and phenotypes. Here we generate an extensive dataset of bacterial Raman spectra and apply deep learning approaches to accurately identify 30 common bacterial pathogens. Even on low signal-to-noise spectra, we achieve average isolate-level accuracies exceeding 82% and antibiotic treatment identification accuracies of 97.0±0.3%. We also show that this approach distinguishes between methicillin-resistant and -susceptible isolates of Staphylococcus aureus (MRSA and MSSA) with 89±0.1% accuracy. We validate our results on clinical isolates from 50 patients. Using just 10 bacterial spectra from each patient isolate, we achieve treatment identification accuracies of 99.7%. Our approach has potential for culture-free pathogen identification and antibiotic susceptibility testing, and could be readily extended for diagnostics on blood, urine, and sputum.

Shunting microfluidic PCR device for rapid bacterial detection

Polymerase chain reaction (PCR) is commonly used for the analysis of nucleic acids in a variety of applications including clinical. There is, however, a need for a low cost portable PCR device that allows rapid identification of pathogenic bacteria. We report a shunting PCR microfluidic device comprising: polycarbonate microfluidic PCR chip; shunting thermal cycler and fluorescence detector. The microfluidic PCR chip – fabricated using micro-milling and thermal fusion bonding for sealing of the cover – was shunted between three double side temperature zones for thermal cycling. Rapid amplification was observed with heating and cooling rates of 1.8 °C/s and 2 °C/s respectively. Lock-in photodetector for fluorescence detection of the microfluidic PCR chip achieved at 95% confidence an LOD of 75pM FITC and 0.7 ng μl−1 of dsDNA using a QuantiFluor assay kit. The device was validated using universal primers - based on chromosomal DNA extracted from non-pathogenic K-12 subtype of Escherichia coli (E. coli) – for amplification of fragments of 250, 552 and 1500 bp. PCR amplification was demonstrated, with annealing temperatures ranging between 54 °C and 68 °C, and confirmed using gel electrophoresis. The developed shunting PCR microfluidic device will allow for low cost and portable nucleic acid amplification for the detection of infectious diseases.

Microbiome analysis of diabetic foot osteomyelitis by metagenome sequencing technology

Objective: To analyze the microbiome of diabetic foot osteomyelitis (DFO) by means of metagenome sequencing and provide evidence for identification of pathogenic bacteria in DFO. Methods: A total of 5 patients (3 males and 2 females) with DFO hospitalized at the Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University were enrolled and infected bone specimens were obtained between September 2016 and April 2017. The mean age was (55.8±9.5) years. Metagenome sequencing was performed to explore the characteristics of microbiome, and compared with the results of 16S rRNA sequencing. Results: The results of metagenome sequencing showed that DFO contained diverse microorganism. Totally, 22 dominant species were obtained, Klebsiella pneumoniae (69.66%) was the most abundant, followed by Veillonella parvula (36.93%) and Prevotella intermedia (34.19%). Compared with the 16S rRNA sequencing, metagenome sequencing could obtain more species information on the basis of fewer samples. At the genus level, both sequencing techniques suggested the most dominant pathogen in DFO was anaerobe. All bone specimens had polymicrobial communities. Conclusions: More microecological diversity and abundance of DFO can be found by using metagenome sequencing. At the species level, more bacteria, even bacterial strains can be identified by metagenome sequencing. At the genus level, the most abundant bacteria is anaerobe, however, at the species level, it is facultative anaerobe.

Frequency and Antimicrobial Susceptibility of the Bacteria Isolated from Blood Cultures of Neonatal

The present study was carried out to determine the prevalence of bacterial isolates responsible for blood stream infection (BSI) among neonatal inpatients at Baghdad Teaching Hospital / Baghdad and to also get an updated knowledge about their antibiotic resistance pattern during the period extended from 1 October till 31 December, 2018. All blood cultures were done by BacT/ALERT 3D device (Bio-Merieux, France). Identification of pathogenic bacteria at species level was done by using API system (Bio-Merieux, France) and the antimicrobial susceptibility testing was done by Kirby-Bauer method. A total of 90 blood cultures were received from neonatal suspected with blood stream infections. Out of 36 positive blood cultures, the incidence of positive blood cultures was higher among males 22(61.1%) than of females 14(38.9%). Out of 36 positive blood cultures, the isolation rate of Gram positive and Gram negative isolates was 25 (69.4%) and 11(30.6%), respectively. Coagulase negative Staphylococci (CoNS) was the most frequently isolated bacteria in blood cultures, 17 (47.22%) isolates. Our study also showed that Klebsiella pneumoniae was the most frequently isolated Gram negative bacteria in blood specimens from neonatal inpatients 6(16.67%). The most effective antibiotic on Gram-positive isolates was Vancomycin, while for Gram negative bacteria the most effective antibiotic was Imipenem. Keywords : Blood stream infection, Antimicrobial susceptibility, Neonatal blood cultures and Bacterial isolates DOI : 10.7176/JBAH/9-14-05 Publication date :July 31 st 2019

Isolation and identification of pathogenic bacteria from ready-to-eat fast foods in Al-Quwayiyah, Kingdom of Saudi Arabia

Isolation and identification of pathogenic bacteria from ready-to-eat fast foods in Al-Quwayiyah, Kingdom of Saudi Arabia

Isolation and identification of pathogenic bacteria from ready-to-eat fast foods in Al-Quwayiyah, Kingdom of Saudi Arabia.

Food-borne pathogens are becoming a globally formidable health problem and perceived as a major health concern in the Kingdom of Saudi Arabia (KSA). Contamination ensued through unclean raw food materials and particles, use of polluted water, unhygienic preparation processes and use of contaminated containers. Herein, the prevalence of food-borne pathogens in ready-to-eat (RTE) fast foods from fifteen different food eateries such as 7 restaurants, 6 cafeterias and 2 two college canteens in Al-Quwayiyah, Riyadh Region of Saudi Arabia was studied. Microbiological analysis of 155 fast food samples which included, Vegetable salad, Falafel, Kibtha and Shawarma. The isolates were detected using biochemical tests and API 20E and slide agglutination test were conducted for Salmonella spp. detection. Bacterial growth was found in all food samples tested. Moreover, the test also showed high levels of total aerobic count: vegetable salad 6.34+0.03, falafel 5.79 + 0.18, kibtha 5.06 +0.02 and shawarma 3.54 + 0.13. Organisms isolated include Salmonella spp. (15%), Escherichia coli (18%) and Staphylococcus aureus (7%). Salmonella is one of the most virulent pathogen implicated in food-borne disease outbreaks. There are numerous transmission routes for Salmonellosis , but the majority of the human infections are derived from consumption of contaminated poultry products. Consistently, Salmonella Enteritidis, Salmonella Typhimurium and Salmonella Heidelberg are the three most frequent serotypes recovered from humans each year. Serologically identified Salmonella serotypes from RTE fast food samples were Salmonella Typhimurium with 65%, the most predominant one compared to Salmonella Enteritidis that was 35%. The bacterial count of vegetable salad, falahfel, kibtha was statistically significant when compared with Shawarma ( p < 0.05). This result indicated that most of the ready-to-eat food samples examined in the study did not meet any bacteriological quality standard as recommended by The New South Wales (NSW) Food Authority to be <5.0 log10 CFU g−1 and, therefore, it poses potential risks to consumers. Ready- to- eat fast foods must be cooked and served to the consumers with all hygienic measures. Keywords: foodborne pathogen, microbial quality, Ready- to- eat fast foods, Al-Quwayiyah Afr. J. Food Agric. Nutr. Dev . 2019; 19(3): 14739-14751

Identification of pathogenic bacteria on the salted fish Lutjanus vivanus in Sorong City of West Papua

Fisheries-based food is needed by humans as a protein source, one of which is salted fish Lutjanus vivanus. Market demand for this product in Indonesia is quite high. The aim of the study was to identify pathogenic bacteria in salted fish L. vivanus. The method used in this study was descriptive method including pathogenic test, bacterial genomic DNA isolation based on 16 sRNA gene using prokaryotic specific primers, namely 63f forward primer (5′-CAGGCC TAA CAC ATG CAA GTC-3′) and reverse 1387r primer (5′-GGG CGG WGT GTA CAA GGC-3′). The results of this study indicated pathogenic bacteria in salted fish L. vivanus with pathogenic activity of α hemolytic and β hemolytic. The bacteria were identified as Serratia marcescens strain ZK2 16S for isolate KS and Bacillus altitudinis strains A-19 16S for isolate LG. In salted fish L. vivanus in the Sorong city, West Papua, it was obtained Serratia marcescens strain ZK2 16S with total hemolytic activity and B. altitudinis A-19 16S strain with partial hemolytic activity.

Colorimetric and Electrochemical Detection of Escherichia coli and Antibiotic Resistance Based on a p-Benzoquinone-Mediated Bioassay.

The facile and economical identification of pathogenic bacteria, especially their antibiotic-resistance, is crucial in the realm of human health and safety. The presence of Escherichia coli ( E. coli) is considered as an indicator of water contamination and is closely related to human health. Herein, inspired by the biocatalysis of bacterial surfaces, we developed a simple and cost-effective colorimetric- and electrochemical-based bioassay that is capable of analyzing both the presence of E. coli and its relative level of antibiotic resistance. In this approach, p-benzoquinone is used as a redox mediator to monitor the bacterial concentration and specifically distinguish E. coli from four other common clinical bacteria, namely, Staphylococcus aureus ( S. aureus), Enterococcus faecalis ( E. faecalis), Salmonella pullorum ( S. pullorum), and Streptococcus mutans ( S. mutans). A visible color change, captured with a smartphone using a "light box", without relying on any complex instruments, can reflect the concentration of bacteria. The accurate quantification of E. coli was investigated with an electrochemical system in the concentration ranges of 1.0 × 103 to 1.0 × 109 CFU/mL. We further demonstrated the capability of the presented biosensor in identifying drug-resistant bacteria with two artificially induced antibiotic-resistant bacteria. Therefore, the presented bioassay is not only capable of detecting E. coli with high sensitivity and specificity but also provides a rapid solution to evaluate E. coli antibiotic resistance.