scholarly journals Microbiological Contamination of Strawberries from U-Pick Farms in Guangzhou, China

Author(s):  
Xiaohong Wei ◽  
Shuiping Hou ◽  
Xinhong Pan ◽  
Conghui Xu ◽  
Juntao Li ◽  
...  

This study quantified the association of rodent fruit damage and the microbiological quality of irrigation water on the risk of microbiological contamination of strawberries collected from 18 U-pick farms across five different districts in the Guangzhou metropolitan region of southern China. Fifty-four composite strawberries samples, with or without evidence of rodent or avian foraging damage (i.e., bitten), along with 16 irrigation water samples, were collected during the spring of 2014 and winter of 2015 from our cohort of 18 farms. Composite strawberry samples and irrigation water were analyzed for total coliforms, E. coli, Salmonella, E. coli O157, Giardia, and Cryptosporidium. Total coliforms and E. coli were detected in 100% and ~90% of irrigation water samples, respectively. In contrast, Cryptosporidium was detected in only two water samples, while Salmonella, E. coli O157, and Giardia were not detected in any water samples. Strawberries with signs of being bitten by wildlife had significantly higher concentrations of total coliforms and E. coli, compared to strawberries with no physical evidence of rodent damage (p < 0.001). Similarly, Cryptosporidium was detected in 7/18 (39%) of bitten, 4/18 (22%) of edge, and 5/18 (28%) of central strawberry samples, respectively. Concentration of E. coli on strawberries (p < 0.001), air temperature (p = 0.025), and presence of Cryptosporidium in irrigation water (p < 0.001) were all associated with the risk of Cryptosporidium contamination on strawberries. Salmonella and Giardia were detected in <4% strawberry samples and E. coli O157 was not detected in any samples. These results indicate the potential food safety and public health risks of consuming unwashed strawberries from U-pick farms, and the need for improved rodent biosecurity of U-pick strawberry fields and enhanced microbiological quality of irrigation water used at these facilities.


2008 ◽  
Vol 54 (6) ◽  
pp. 495-500 ◽  
Author(s):  
B. Lévesque ◽  
D. Pereg ◽  
E. Watkinson ◽  
J.S. Maguire ◽  
L. Bissonnette ◽  
...  

Bermuda residents collect rainwater from rooftops to fulfil their freshwater needs. The objective of this study was to assess the microbiological quality of drinking water in household tanks throughout Bermuda. The tanks surveyed were selected randomly from the electoral register. Governmental officers visited the selected household (n = 102) to collect water samples and administer a short questionnaire about the tank characteristics, the residents’ habits in terms of water use, and general information on the water collecting system and its maintenance. At the same time, water samples were collected for analysis and total coliforms and Escherichia coli were determined by 2 methods (membrane filtration and culture on chromogenic media, Colilert kit). Results from the 2 methods were highly correlated and showed that approximately 90% of the samples analysed were contaminated with total coliforms in concentrations exceeding 10 CFU/100 mL, and approximately 66% of samples showed contamination with E. coli. Tank cleaning in the year prior to sampling seems to protect against water contamination. If rainwater collection from roofs is the most efficient mean for providing freshwater to Bermudians, it must not be considered a source of high quality drinking water because of the high levels of microbial contamination.



Author(s):  
TATIANNE OLIVEIRA ◽  
Eveline Gomes Rosa de Moura ◽  
Thaynara Cristina de Oliveira ◽  
Daniela Ayumi Amemiya ◽  
Carolina Fernandes Nobre ◽  
...  

The aim of this work was to evaluate the nutritional and microbiological quality of ready-to-eat açai, the physical and functional conditions of establishments that market this product and to verify the presence of microorganisms at handlers’ hands and nostrils. Twenty-three establishments in the city of Goiânia–Goiás were evaluated and açaí samples were obtained in two steps: before and after the training of handlers about good manufacturing practices. A decrease in the counts of total coliforms (from 26.08% to 8.7% of samples), coagulase positive staphylococci (from 78.26% to 65.2% of samples) and aerobic mesophiles (from 100% to 73.91% of samples) was observed between steps. The presence of microorganisms at handlers’ hands and nostrils did not present statistical difference between the two steps. According to the applied checklist, six items showed reduced compliance. After the training of handlers, the microbiological contamination of açaí decreased, and the presence of E coli in handlers’ nostrils was no longer observed, which highlights the importance of training about the implementation Good Manufacturing Practices to ensure food sanitary quality.



2009 ◽  
Vol 8 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Marta Sofia Valente ◽  
Paulo Pedro ◽  
M. Carmen Alonso ◽  
Juan J. Borrego ◽  
Lídia Dionísio

Monitoring the microbiological quality of water used for recreational activities is very important to human public health. Although the sanitary quality of recreational marine waters could be evaluated by standard methods, they are time-consuming and need confirmation. For these reasons, faster and more sensitive methods, such as the defined substrate-based technology, have been developed. In the present work, we have compared the standard method of membrane filtration using Tergitol-TTC agar for total coliforms and Escherichia coli, and Slanetz and Bartley agar for enterococci, and the IDEXX defined substrate technology for these faecal pollution indicators to determine the microbiological quality of natural recreational waters. ISO 17994:2004 standard was used to compare these methods. The IDEXX for total coliforms and E. coli, Colilert®, showed higher values than those obtained by the standard method. Enterolert® test, for the enumeration of enterococci, showed lower values when compared with the standard method. It may be concluded that more studies to evaluate the precision and accuracy of the rapid tests are required in order to apply them for routine monitoring of marine and freshwater recreational bathing areas. The main advantages of these methods are that they are more specific, feasible and simpler than the standard methodology.



2008 ◽  
Vol 71 (6) ◽  
pp. 1253-1257 ◽  
Author(s):  
SÉRGIO A. P. NUNES FILHO ◽  
ANDERSON S. SANT'ANA ◽  
ADRIANO G. CRUZ

The objective of the present study was to determine the microbiological quality of bottled mineral water marketed in commercial establishments and by street vendors and to evaluate the influence of the storage and maintenance conditions on the microbiological quality of the product. Ten samples from the same batches of five different brands of water were analyzed, for a total of 50 samples. Of the five brands analyzed, only one (brand A), when collected in a commercial establishment, complied with the legal Brazilian standards for mineral water with respect to the presence of total coliforms, fecal coliforms, and Pseudomonas aeruginosa. The remaining samples failed to comply with these microbiological standards for at least one of the parameters evaluated. The water samples obtained from street vendors were inferior in microbiological quality to samples from the same batch that were obtained from commercial establishments.



2020 ◽  
Vol 49 (1) ◽  
pp. 32-39 ◽  
Author(s):  
A. Vásquez García ◽  
S.H. Gomes de Sá ◽  
G. de Sousa Silva ◽  
J.E. Mejia Ballesteros ◽  
E. Barbieri ◽  
...  

The objective of this study was to evaluate the microbiological quality of oysters and mussels grown in Cananéia, Brazil, by analysing mesophiles, psychrothophic bacteria, moulds and yeasts, Staphylococcus aureus, and Salmonella spp., and to compare the efficiency of Compact Dry EC method and the conventional method for counting of total coliforms and Escherichia coli. The microbial analysis showed that the mean values of mesophilic counts were 3.14±0.81 log CFU g−1 for oysters and 3.92±0.90 for mussels; the mean values of psychrophilic counts were 2.78±0.75 log CFU g−1 for oysters and 3.22±0.75 log CFU g−1 for mussels; the mean values of mould and yeast counts were 3.70±0.58 log CFU g−1 for oysters and 3.33±0.81 log CFU g−1 for mussels. Salmonella spp. did not present positive results, and the maximal count of Staphylococcus aureus was 1.7 log CFU g−1, therefore, within the limits established in the legislation. The correlation coefficients between the Compact Dry EC method and conventional method were >0.87 for total coliform and E. coli counts for both types of shellfish. The data in this study show that the Compact Dry EC method is an acceptable alternative to conventional methods for enumeration of total coliforms and E. coli in shellfish.



2016 ◽  
Vol 14 (3) ◽  
Author(s):  
Nur Zumairotul Muna ◽  
AT. Diana Nerawati ◽  
Rachmaniyah .

Crystal ice cube consumed by people is distributed through distribution chain from factories, agents, and ice traders in Surabaya. Each distribution chain posses risk of contamination to the quality of the ice, one of which is microbiological contamination that cause health problems to consumers. This is descriptive study aimed to obtain microbiological quality of crystal ice cube and hygiene sanitation throughout distribution chain in Surabaya. Sampling and observations were conducted sequentially in the same day, in different time and with 3 time repetition for 3 days in a row. Data were analyzed descriptively. The result showed  that the ice crystals did not contain E. coli yet contained MPN Coliform. The rate of MPN Coliform on ice at factory  was 10 colonies / 100 cc sample, at agent was 12-15 colonies / 100 cc sample, and at merchant were 15-43 colonies / 100 cc sample. Hygiene sanitation affecting MPN Coliform in crystal ice are non standard raw materials, production process, transportation, and the handlers. In conclusion, microbiological quality of crystal ice cube along the distribution chain in Surabaya with E. coli parameter did not meet standard. Health Department needs to conduct surveillance on a regular basis. Factory of ice cube needs to  make Standard Operating Procedures. Agents  and traders need to improve hygiene sanitation of conveyance, transport personnel, equipment, and handlers.  Keywords : Ice Cube Crystals, Chain Distribution, Hygiene Sanitation, MPN Coliform, E. coli



2015 ◽  
Vol 78 (4) ◽  
pp. 643-651 ◽  
Author(s):  
ERIKA M. du PLESSIS ◽  
FRANCOIS DUVENAGE ◽  
LISE KORSTEN

The potential transfer of human pathogenic bacteria present in irrigation water onto fresh produce was investigated, because surface water sources used for irrigation purposes in South Africa have increasingly been reported to be contaminated with enteric bacterial pathogens. A microbiological analysis was performed of a selected river in Limpopo Province, South Africa, that is often contaminated with raw sewage from municipal sewage works and overhead irrigated onions produced on a commercial farm. Counts of Escherichia coli, coliforms, aerobic bacteria, fungi, and yeasts and the prevalence of E. coli O157:H7, Salmonella, and Listeria monocytogenes were determined. Identities of bacterial isolates from irrigation water and onions were confirmed using matrix-assisted laser desorption ionization–time of flight mass spectrometry, PCR, and biochemical tests. To establish a potential link between the microbiological quality of the irrigation source and the onions, the E. coli isolates from both were subjected to antibiotic resistance, virulence gene, and enterobacterial repetitive intergenic consensus PCR analyses. River water E. coli counts exceeded South African Department of Water Affairs and World Health Organization irrigation water guidelines. Counts of aerobic bacteria, coliforms, fungi, and yeasts of onions from the market were acceptable according to Department of Health Directorate, Food Control, South Africa, microbiological guidelines for ready-to-eat fresh fruits and vegetables. E. coli O157:H7, Salmonella, and L. monocytogenes were not detected in onions, whereas only Salmonella was detected in 22% of water samples. Matrix-assisted laser desorption ionization–time of flight mass spectrometry and PCR identification of E. coli isolates from water and onions correlated. Of the 45 E. coli isolates from water and onions, 42.2% were resistant to multiple antibiotics. Virulence genes eae, stx1, and stx2 were detected in 2.2, 6.6, and 2.2% of the E. coli isolates, respectively. Phenotypic (antimicrobial) and genotypic (virulence gene prevalence, DNA fingerprinting) analyses showed a link between river, dam, irrigation pivot point, and onion E. coli isolates.



2003 ◽  
Vol 1 (3) ◽  
pp. 101-108 ◽  
Author(s):  
P. Jagals ◽  
C. Jagals ◽  
T. C. Bokako

Studies in Southern Africa have shown that even when microbiologically safe water is supplied to developing communities at communal standpipes, contamination by high numbers of pathogenic microorganisms may occur during the processes of fetching water from the supply source and storage during use at home, rendering such waters unsafe for human consumption. This study investigated the occurrence of biofilm in PVC storage containers as one possible reason for this deterioration, using heterotrophic bacteria and total coliform counts as well as turbidity as indicators. A second objective was to determine whether biofilm in water-storage containers could contribute to hazardous microbiological contamination indicated by Escherichia coli and Clostridium perfringens. Results indicated that increased microbiological contamination is associated with biofilm. The biofilm harbours heterotrophic bacteria, total coliforms and C. perfringens. E. coli could not be associated directly with the levels of biofilm in containers but rather appears to be introduced intermittently from the ambient domestic environment. When dislodged with the biofilm, these bacteria contributed substantially to the deterioration of the microbiological quality of supplied water stored in plastic containers.



2016 ◽  
Vol 59 (3) ◽  
pp. 83-87 ◽  
Author(s):  
Luckrezia Awuor ◽  
Sylvanus Thompson ◽  
Brian Thompson ◽  
Eric N. Liberda ◽  
Richard Meldrum

Consumable ice presents a potential hazard due to microbiological contamination. To investigate the microbiological quality and handling practices of ice served in selected food premises in downtown Toronto, Ontario, 64 ice samples were collected from 40 food establishments. The ice samples were tested for the presence/absence of total coliforms and Escherichia coli. Five samples (7.8%) tested positive for total coliforms, all of which were sampled from the customer service areas. None of the ice samples tested positive for E. coli. A visual inspection was carried out to determine general ice handling practices in the food premises sampled. Of the 40 premises sampled, 14 (35%) had dirty ice holding/storage equipment, 13 (32.5%) had inappropriately stored scoops, and 6 (15%) had visible biofilm on the ice machines. In 15 (37.5%) premises, the ice was uncovered when not in use and 4 (10%) premises had food safety violations relating to the inability to protect food from contamination. The presence of total coliforms and the lack of proper ice handling practices among several food premises suggest that consumable ice served in downtown Toronto food premises may present a potential hazard.



Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1708
Author(s):  
Matthew Stocker ◽  
Dong Jeon ◽  
Ekaterina Sokolova ◽  
Hoonsoo Lee ◽  
Moon Kim ◽  
...  

Evaluating the microbial quality of irrigation water is essential for the prevention of foodborne illnesses. Generic Escherichia coli (E. coli) is used as an indicator organism to estimate the microbial quality of irrigation water. Monitoring E. coli concentrations in irrigation water sources is commonly performed using water samples taken from a single depth. Vertical gradients of E. coli concentrations are typically not measured or are ignored; however, E. coli concentrations in water bodies can be expected to have horizontal and vertical gradients. The objective of this work was to research 3D distributions of E. coli concentrations in an irrigation pond in Maryland and to estimate the dynamics of E. coli concentrations at the water intake during the irrigation event using hydrodynamic modeling in silico. The study pond is about 22 m wide and 200 m long, with an average depth of 1.5 m. Three transects sampled at 50-cm depth intervals, along with intensive nearshore sampling, were used to develop the initial concentration distribution for the application of the environmental fluid dynamic code (EFDC) model. An eight-hour irrigation event was simulated using on-site data on the wind speed and direction. Substantial vertical and horizontal variations in E. coli concentrations translated into temporally varying concentrations at the intake. Additional simulations showed that the E. coli concentrations at the intake reflect the 3D distribution of E. coli in the limited pond section close to the intake. The 3D sampling revealed E. coli concentration hot spots at different depths across the pond. Measured and simulated 3D E. coli concentrations provide improved insights into the expected microbial water quality of irrigation water compared with 1D or 2D representations of the spatial variability of the indicator concentration.



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