scholarly journals Microbial contaminants in wild harvested and traded edible long-horned grasshopper, Ruspolia differens (Orthoptera: Tettigoniidae) in Uganda

2021 ◽  
pp. 1-12
Author(s):  
S. Labu ◽  
S. Subramanian ◽  
F.M. Khamis ◽  
P. Akite ◽  
P. Kasangaki ◽  
...  
Keyword(s):  
Health Risks ◽  
Pathogenic Bacteria ◽  
Molecular Techniques ◽  
Deep Frying ◽  
Informal Markets ◽  
Pure Cultures ◽  
Wild Vegetation ◽  
Microbial Contaminants ◽  
Handling Practices ◽  
Trapping Sites

This study investigated the relative abundance and identity of microbial contaminants of the edible long-horned grasshopper (Ruspolia differens) harvested from the wild and traded in informal markets in Uganda, to reveal high health risk points. Raw samples of whole R. differens were collected from wild vegetation, trapping sites and markets. Additionally, samples of plucked and deep-fried ready-to-eat R. differens were collected from the markets. The samples were cultured on standard media for microbial quantification, and pure cultures were characterised using molecular techniques. Bacterial and fungal counts in deep fried ready-to-eat R. differens were ~3- and 2-fold lower, respectively, than in raw samples. Loads of these microbes in deep fried insects were within recommended food safety limits. The highest bacterial counts were detected in whole R. differens samples from the market followed by trapping points. The fungal counts in the raw R. differens were comparable across the sampling points. The bacterial and fungal counts in R. differens in Kampala were not influenced by district of origin. Seven species of bacteria and seven species of fungi were recorded in R. differens samples. The microbial species were most diverse in samples from trapping points and least diverse in the deep-fried insects. The key pathogenic bacteria detected in marketed R. differens were Staphylococcus sciuri, Acinetobacter baumannii and Serratia marcescens, all of which were absent in wild-caught whole insects. Our results demonstrate that R. differens obtained at the trapping sites and markets are contaminated with potentially harmful microbes, therefore they require processing through deep frying to minimise health risks associated with their consumption. Further studies are warranted to elucidate specific handling practices at distribution and trapping points which may prevent introduction of microbes into R. differens.

scholarly journals Occurrence of Bacterial Stem Rot, Caused by Erwinia chrysanthemi, on Field-Grown Tomato in Florida

Plant Disease ◽  
1998 ◽  
Vol 82 (7) ◽  
pp. 831-831 ◽  
Author(s):  
D. O. Chellemi ◽  
H. A. Dankers ◽  
K. Hill ◽  
R. E. Cullen ◽  
G. W. Simone ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Methyl Esters ◽  
Sole Source ◽  
Erwinia Chrysanthemi ◽  
Identification System ◽  
Bacterial Cells ◽  
Sterile Water ◽  
Microbial Identification ◽  
Pure Cultures ◽  
Tomato Isolate

In September 1997, wilted 4-week-old tomato (Lycopersicon esculentum Mill.) plants were observed in a commercial production field in St. Lucie County, FL. Closer inspection of affected plants revealed hollow stems and petioles with dark, water-soaked lesions. Diseased tissue was macerated and streaked onto nutrient agar (NA) and crystal violet pectate (CVP) agar. After incubation for 2 days at 30°C, isolates produced pits on the CVP agar. Isolates were transferred onto NA and the incubation and transfer procedure was performed two additional times to obtain pure cultures. Suspensions of bacterial cells were injected into tomato and tobacco leaves to test for a hypersensitive or pathogenic reaction. Isolates produced collapsed necrotic tissue on tomato while no reaction was observed on tobacco. Tests for differentiating species and subspecies in the ‘carotovora’ group of Erwinia were conducted following the protocol of Dickey and Kelman (1). With known cultures of E. carotovora subsp. carotovora and E. chrysanthemi as controls, the isolate from tomato was determined to function as a facultative anaerobe, utilize asparagine as a sole source of carbon and nitrogen, and give positive reactions for pectate degradation, phosphatase, and growth at 37°C. Known cultures of E. carotovora subsp. carotovora, E. chrysanthemi, and the tomato isolate were grown on trypticase soy broth agar for 24 h at 28°C and their cellular fatty acids derivatized to fatty acid methyl esters (FAMEs). Statistical analyses of FAME profile data (MIDI Microbial Identification System, Newark, DE, version 3.60) identified the tomato isolate as Erwinia chrysanthemi. Pathogenicity was determined by inoculating 50-day-old tomato plants (cv. SunPride) with a suspension of E. chrysanthemi obtained from nutrient broth plates incubated at 24°C for 60 h. Three plants each were inoculated with the E. chrysanthemi identified from tomato, sterile water, and known cultures of E. chrysanthemi and E. carotovora subsp. carotovora by placing a drop at the junction of the petiole and stem and passing a sterile needle through the drop into the stem. Plants were maintained in a greenhouse. Dark, water-soaked cankers were observed on the stems of plants inoculated with E. chrysanthemi, including the tomato isolate and E. carotovora subsp. carotovora, after 7 days. No symptoms were observed on plants inoculated with sterile water. Reisolation of the pathogen and identification was performed with tissue from one of the symptomatic inoculated plants. Analyses of FAMEs confirmed E. chrysanthemi as the causal agent. This is the first report of E. chrysanthemi causing a vascular disease of field-grown tomato in Florida. Reference: (1) R. S. Dickey and A. Kelman. 1988. Pages 44–59 in: Laboratory Guide for Identification of Plant Pathogenic Bacteria. N. W. Schaad, ed. American Phytopathological Society, St. Paul, MN.

scholarly journals Chemical composition, safety and quality attributes of traditional cottage sausage

2019 ◽  
Vol 37 (No. 5) ◽  
pp. 325-331
Author(s):  
Krzysztof Surówka ◽  
Ireneusz Maciejaszek ◽  
Kamila Walczak ◽  
Maria Walczycka ◽  
Barbara Surówka ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Health Risks ◽  
Pathogenic Bacteria ◽  
Salt Content ◽  
Principal Component ◽  
Cholesterol Content ◽  
Product Diversity ◽  
Potential Health ◽  
Characteristic Features ◽  
Ph Level

The characteristic features of traditional cottage sausage were analysed. In addition, the extent to which manufacturers create product diversity on the market was investigated, along with potential health risks of the product to consumers. The samples had high overall sensory scores. The average level of fat slightly exceeded 28%, cholesterol content was in the range of 435.4–1220.3 mg/kg and salt content was 1.53–2.77%. Some manufacturers do not cure their product, but about 20% of them apply nitrites above the level of 150 mg/kg. Due to their relatively high pH level (5.76–6.60) and water activity (0.95–0.98), Polish cottage sausage can be a medium which encourages the growth of microorganisms; however, pathogenic bacteria were not found. Histamine was detected in only 42% of the samples, at the low level of 2.6 to 34.2 mg/kg. Principal Component Analysis (PCA) was applied and the dominant variables were specified for particular PCs.

Evaluation of methods for isolation of DNA for PCR based identification of pathogenic bacteria from pure cultures and water samples

2009 ◽  
Vol 59 (3) ◽  
pp. 619-620
Author(s):  
K. Horáková ◽  
H. Mlejnková ◽  
P. Mlejnek
Keyword(s):  
Water Samples ◽  
Pathogenic Bacteria ◽  
Science And Technology ◽  
Pure Cultures ◽  
Water Science ◽  
Evaluation Of Methods

Water Science and Technology 58(5), 995–999 Publisher's note. We regret that the version of this article used in production did not incorporate a number of corrections and clarifications. The corrected versions of the text are as given below.

Evaluation of methods for isolation of DNA for polymerase chain reaction (PCR)-based identification of pathogenic bacteria from pure cultures and water samples

2008 ◽  
Vol 58 (5) ◽  
pp. 995-999 ◽  
Author(s):  
K. Horáková ◽  
H. Mlejnková ◽  
P. Mlejnek
Keyword(s):  
Polymerase Chain Reaction ◽  
Water Samples ◽  
Pathogenic Bacteria ◽  
Pcr Amplification ◽  
Bacterial Suspension ◽  
Chain Reaction ◽  
Alkaline Lysis ◽  
Bacterial Dna ◽  
Pure Cultures ◽  
Polymerase Chain

Polymerase chain reaction (PCR) provides a reliable detection of pathogenic bacteria in water samples. However, this method can be adversely influenced by the purity of the DNA template. This is a particularly important obstacle when the bacterial DNA is directly extracted from water samples. In this study we compared the suitability of 8 different methods for isolation of bacterial DNA from pure cultures and 10 different methods for isolation of DNA from water samples. The quality of extracted DNA was assessed by PCR amplification of target sequences derived from uid (E. coli and Shigella sp.), tuf (Enterococcus sp.) and hns (Salmonella sp.). Results indicated that there are differences among the methods tested and only a few of them gave satisfactory results. The method based on alkaline lysis of bacterial suspension, which was developed in our laboratory, seemed to be efficient enough for the detection of bacteria from pure cultures. Detection of bacteria directly from water samples was more difficult. The modified method developed by Slusarenko was found as the best of the tested methods.

Efficacy of Neutral Electrolyzed Water for Reducing Pathogenic Bacteria Contaminating Shrimp

2014 ◽  
Vol 77 (12) ◽  
pp. 2176-2180 ◽  
Author(s):  
PATTAMA RATANA-ARPORN ◽  
NARUEMON JOMMARK
Keyword(s):  
Salmonella Enteritidis ◽  
Pathogenic Bacteria ◽  
Vibrio Vulnificus ◽  
Safety Concern ◽  
Microbiological Quality ◽  
Slight Reduction ◽  
Electrolyzed Water ◽  
Prolonged Contact ◽  
Pure Cultures ◽  
New Applications

Pathogenic contamination is a food safety concern. This study was conducted to investigate the efficacy of neutral electrolyzed water (NEW) in killing pathogens, namely, Vibrio parahaemolyticus, Vibrio vulnificus, Salmonella Enteritidis, and Escherichia coli in shrimp. Pure cultures of each pathogen were submerged separately in NEW containing five different chlorine concentrations: 10, 30, 50, 70, and 100 ppm. For each concentration, three submersion times were tested: 1, 3, and 5 min. The population of V. parahaemolyticus was rapidly reduced even at low concentrations, but prolonged contact times caused only a slight reduction. V. vulnificus was gradually inhibited with increasing NEW concentrations and contact times. For the V. parahaemolyticus applications of 70 ppm for 5 min and of 100 ppm for 3 min, each eliminated 7 log CFU/ml. For V. vulnificus, applications of 50 ppm for 3 min and 100 ppm for 1 min, each eliminated 7 log CFU/ml. Salmonella Enteritidis and E. coli were slightly reduced by NEW. Applications of 50 ppm for 15 min and 10 ppm for 30 min completely eliminated 4.16 log CFU/g of V. parahaemolyticus in inoculated shrimp, while only a 1-log CFU/g reduction of V. vulnificus was detected. Soaking shrimp in 10 ppm NEW for 30 min did not affect its sensory quality. Our results suggest NEW could be an alternative sanitizer to improve the microbiological quality of seafood.

scholarly journals Growth and Methane Oxidation Rates of Anaerobic Methanotrophic Archaea in a Continuous-Flow Bioreactor

2003 ◽  
Vol 69 (9) ◽  
pp. 5472-5482 ◽  
Author(s):  
Peter R. Girguis ◽  
Victoria J. Orphan ◽  
Steven J. Hallam ◽  
Edward F. DeLong
Keyword(s):  
Methane Oxidation ◽  
Continuous Flow ◽  
Molecular Techniques ◽  
Anaerobic Methane Oxidation ◽  
Cold Seep ◽  
Microbial Consortia ◽  
Sulfate Reducing ◽  
Oxidation Rates ◽  
In Situ Conditions ◽  
Pure Cultures

ABSTRACT Anaerobic methanotrophic archaea have recently been identified in anoxic marine sediments, but have not yet been recovered in pure culture. Physiological studies on freshly collected samples containing archaea and their sulfate-reducing syntrophic partners have been conducted, but sample availability and viability can limit the scope of these experiments. To better study microbial anaerobic methane oxidation, we developed a novel continuous-flow anaerobic methane incubation system (AMIS) that simulates the majority of in situ conditions and supports the metabolism and growth of anaerobic methanotrophic archaea. We incubated sediments collected from within and outside a methane cold seep in Monterey Canyon, Calif., for 24 weeks on the AMIS system. Anaerobic methane oxidation was measured in all sediments after incubation on AMIS, and quantitative molecular techniques verified the increases in methane-oxidizing archaeal populations in both seep and nonseep sediments. Our results demonstrate that the AMIS system stimulated the maintenance and growth of anaerobic methanotrophic archaea, and possibly their syntrophic, sulfate-reducing partners. Our data demonstrate the utility of combining physiological and molecular techniques to quantify the growth and metabolic activity of anaerobic microbial consortia. Further experiments with the AMIS system should provide a better understanding of the biological mechanisms of methane oxidation in anoxic marine environments. The AMIS may also enable the enrichment, purification, and isolation of methanotrophic archaea as pure cultures or defined syntrophic consortia.

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