Risk evaluation for pathogenic bacteria and viruses in sewage sludge compost

2002 ◽  
Vol 46 (11-12) ◽  
pp. 325-330 ◽  
Author(s):  
T. Watanabe ◽  
D. Sano ◽  
T. Omura

Composting can be regarded as the most available option for recycling of sewage sludge. However, the existence of pathogenic bacteria and viruses in the compost has been scarcely investigated until now. So there is little information on the infectious risk through agricultural activities or gardening in using the compost. In this study, several kinds of composts were investigated for detection of pathogenic bacteria (Salmonella spp. and Escherichia coli O 157) and enteric viruses. It was concluded from the result that these bacteria and viruses could not be detected in 1.0 g-wet of any kinds of composts. Infectious risks through agricultural activities or gardening were evaluated by Monte Carlo simulation in the case that the compost was polluted by Salmonella spp., E. coli O 157:117 and Poliovirus 1. Criteria satisfying the acceptable risk (less than 10−4 per year) for these pathogenic bacteria and virus in the compost were determined from the result of simulations. 1.0 [CFU or PFU/g-wet] was available as the criteria for E. coli O157 and Poliovirus 1 in the compost. On the other hand, the criterion for Salmonella spp. in the compost should be established on a lower concentration than 0.001 CFU/g-wet.

2014 ◽  
Vol 6 (4) ◽  
pp. 478-482
Author(s):  
Razieh VALIASILL ◽  
Majid AZIZI ◽  
Maasome BAHREINI ◽  
Hossein AROUIE

Medicinal plants may be exposed to a wide range of microbial contamination during pre- and post- harvest stages and they can present high microbial counts. In this study, the microbial quality of 44 samples of dry herbs namely: mint (Menthaspp.), lemon balm (Melissa officinalis), summer savory (Satureja hortensis), zataria (Zataria multiflora), Indian valerian (Valeriana wallichii), their brewing and extracts were analyzed. Total count using plate count agar medium (PCA), coliform count by Violet Red Bile Agar (VRBL), Enterobacteriacea by Violet Red Bile Glucose (VRBG) were evaluated. Medium Baird-Parker agar (BP) medium and Tryptone Bile X-Gluc (TBX) medium were used for the isolation and enumeration of Staphylococcus aurous and E. coli spp. respectively. Furthermore, Xylose Lysine Deoxycholate agar medium (XLD) and Bismuth Sulfite Agar medium(BSA) were used for detection of Salmonella spp. Fungal and mold contamination was assessed using yeast extract glucose chloramphenicol agar. The results showed that the contamination of the samples with total count (100%) and Enterobacteriaceae (85%), total coliform (83%), mold and yeast (98%) and E. coli ssp. (2.27) were detected, including in the study samples the absence of pathogenic bacteria like Staphylococcus aurous, Salmonella spp. Moreover, the extract had a lower microbial load in comparison to dry herb samples. Also, the lowest and the highest of contamination rates were observed for Indian valerian and zataria, respectively. According to the results, there is a need to control the environmental conditions and improve hygiene in the production process; even more, it is recommended to choose a suitable decontamination method for disinfection during packing medicinal plants and during post-packing manipulation and transport.


2005 ◽  
Vol 68 (2) ◽  
pp. 296-304 ◽  
Author(s):  
TIFFANY T. Y. GUAN ◽  
GREGORY BLANK ◽  
RICHARD A. HOLLEY

The ability of Salmonella, Escherichia coli O157:H7, Listeria monocytogenes, and Shigella to survive or grow in pesticide solutions (Ambush 240EC, Benlate T-N-G, Bravo 500, Botran 75WP, Captan 80WDG, Parasol, and Vendex 50W) used by the horticultural industry was examined. In the laboratory, individual cultures were inoculated at 4 log CFU/ml in pesticides diluted with sterile saline to the lowest recommended spray concentrations. During 21°C incubation for ≤96 h, bacterial survivors in the samples and a control consisting of saline were enumerated either by agar surface plating or hydrophobic grid membrane filtration. Most formulations tested were somewhat inhibitory to the pathogenic bacteria. All inoculated bacteria survived or grew in Bravo 500. Among bacteria tested, Salmonella spp. were best able to survive and Listeria spp. were least able to survive in pesticide solutions. When the incubation temperature or pesticide concentration was increased, survival of Salmonella varied depending on the type of formulation. In the field, when a bacterial cocktail containing E. coli O157:H7 and Salmonella Enteritidis was added to Bravo 500 at 6 log CFU/ml, both organisms were recovered from leaves and fruit skins of sprayed tomato plants after the recommended 1 day-to-harvest interval. E. coli and Salmonella survived longer on tomato leaves when sprayed in saline (at least 26 and 56 days, respectively) than when sprayed in Bravo 500 (>45 h and <15 days, respectively). While Salmonella serovars Typhimurium and Heidelberg grew in the fungicide Bravo, and Enteritidis grew in the insecticide Vendex within 96 h at 21°C in the laboratory, pathogen growth in other pesticide formulations did not occur. Higher temperature (≤30°C) or doubling pesticide concentrations had either no or a negative effect on Salmonella Heidelberg survival. Use of unexpired pesticide formulations may have contributed to the reduced bacterial survival and growth found in the laboratory and during the field trials with Bravo.


2013 ◽  
Vol 8 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Adel A. S. AL-Gheethi ◽  
Norli Ismail ◽  
J. Lalung ◽  
Azieda Talib ◽  
A. N. Efaq ◽  
...  

The objective of this work was to study the prevalence of antibiotic resistance phenotypes among total coliforms (TC), E. coli, E. faecalis and Salmonella spp. in the sewage treated effluents generated from three sewage treatment plants in Penang Malaysia. Among the isolates tested, TC and E. coli occurred high resistance for cephalexin (100 and 90.47%), ampicillin (80.93 and 95.23%) and ciprofloxacin (19.06 and 14.3%) compared to E. faecalis (42.86, 71.4 and 4.7%) and Salmonella spp. (59.8, 47.46 and 14.3%) respectively. All E. coli strains, 76.18% of TC, 66.66% of E. faecalis and 35% of Salmonella spp. were multi-resistant.


1997 ◽  
Vol 60 (5) ◽  
pp. 485-492 ◽  
Author(s):  
ABBEY L. NUTSCH ◽  
RANDALL K. PHEBUS ◽  
M. JAMES RIEMANN ◽  
DAVID E. SCHAFER ◽  
J. E. BOYER ◽  
...  

The effectiveness of a steam pasteurization process for reducing naturally occurring bacterial populations on freshly slaughtered beef sides was evaluated in a large commercial facility. Over a period of 10 days, 140 randomly chosen beef sides were microbiologically analyzed. Each side was sampled immediately before, immediately after, and 24 h after steam pasteurization treatment. Total aerobic bacteria (APC), Escherichia coli (generic), coliform, and Enterobacteriaceae populations were enumerated. The process significantly (P ≤ 0.01) reduced mean APCs from 2.19 log CFU/cm2 before treatment to 0.84 log CFU/cm2 immediately after and 0.94 log CFU/cm2 24 h after treatment. Before pasteurization (8 s steam exposure), 16.4% of carcasses were positive for generic E. coli (level of 0.60 to 1.53 log CFU/cm2), 37.9% were positive for coliforms (level of 0.60 to 2.26 log CFU/cm2), and 46.4% were positive for Enterobacteriaceae (level of 0.60 to 2.25 log CFU/cm2). After pasteurization, 0% of carcasses were positive for E. coli, 1.4% were positive for coliforms (level of 0.60 to 1.53 log CFU/cm2), and 2.9% were positive for Enterobacteriaceae (level of 0.60 to 1.99 log CFU/cm2). Of the 140 carcasses evaluated, one carcass was positive for Salmonella spp. before treatment (0.7% incidence rate); all carcasses were negative after steam treatment. This study indicates that steam pasteurization is very effective in a commercial setting for reducing overall bacterial populations on freshly slaughtered beef carcasses. The system may effectively serve as an important critical control point for HACCP systems at the slaughter phase of beef processing. In conjunction with other antimicrobial interventions (mandated by USDA to achieve zero tolerance standards for visible contamination) and good manufacturing practices, this process can play an important role in reducing the risk of pathogenic bacteria in raw meat and meat products.


2013 ◽  
Vol 5 ◽  
pp. 107
Author(s):  
Luis A. Vega Corrales ◽  
Carolina Marín Vindas ◽  
Oscar Pacheco Prieto ◽  
Gerardo Zúñiga Calero

Bivalve molluscs are sold without any sanitary control in Costa Rica, which represents a public health risk dueto the possible accumulation of pathogenic bacteria. Small scale bacterial depuration treatments were preliminarilyevaluated on Crassostrea gigas and Anadara spp. from the Gulf of Nicoya, Costa Rica, through the useof a recirculating system with UV irradiation. The levels of Escherichia coli in the water were determined usingthe MPN method. The MPN of E. coli and the presence of Salmonella spp., Vibrio parahaemolyticus and V. cholerae were determined in molluscs. Results confirm the effectiveness of the E. coli depuration system designin C. gigas and Anadara spp. The MPN of E. coli in the molluscs was reduced between 79% and 100% after 24h. None of the other types of bacteria were found in the samples analyzed. This is the first C. gigas depurationstudy in Costa Rica and the first report concerning UV depuration for bacterial indicators of fecal contaminationin Anadara spp. This research serves as a basis for the implementation and improvement of mollusc purification conditions in the country. It is recommended to monitor extraction and harvesting areas, as well as to implement the depuration of bivalve molluscs so that traditional producers can offer an innocuous product with added value.Los moluscos bivalvos son comercializados sin ningún control sanitario en Costa Rica; por tanto, representan un riesgo para la salud pública, debido a que pueden acumular bacterias patógenas. Se evaluaron preliminarmente tratamientos para la depuración bacteriana a pequeña escala de Crassostrea gigas y Anadara spp. en el Golfo de Nicoya, Costa Rica, utilizando un sistema recirculado e irradiado con luz UV. Los niveles de Escherichia coli en el agua se determinaron mediante el método del NMP. A los moluscos se les determinó el NMP de E. coli y la presencia de Salmonella spp., Vibrio parahaemolyticus y V. cholerae. Los resultados confirman la efectividad del diseño del sistema para la depuración de E. coli en C. gigas y Anadara spp. A las 24 h, el NMP de E. coli en los moluscos se redujo entre el 79% y el 100%. No se comprobó la presencia de las demás bacterias en las muestras analizadas. Este es el primer estudio sobre depuración de C. gigas en Costa Rica y el primer reporte de depuración con UV de indicadores bacterianos de contaminación fecal en Anadara spp. Este trabajo sirve de base para implementar y mejorar las condiciones de la depuración de moluscos en el país. Se recomienda monitorear las áreas de extracción y cultivo e implementar la depuración de los moluscos bivalvos para que los productores artesanales puedan ofrecer un producto inocuo y con valor agregado.


2018 ◽  
pp. 1-10

Dental caries is the most contagious disease throughout the world. In the present study, a total of 100 dental caries patients were selected and samples from these patients were collected through sterile pincers for microbiological examination. A total of 9 different pathogenic bacterial isolates were identified through conventional culturing technique and among them maximum number of occurrence was by Salmonella spp (26.13%), followed by E. coli (17.39%), Proteus spp (17.39%), Shigella spp (8.69%), Pseudomonas spp (8.69%), Vibrio spp (8.69%), Enterobacter spp (4.34%), Yersinia spp (4.34%) and S. mutans (4.34%). Furthermore, antibiotic susceptibility tests were performed by 9 different commercially available antibiotics i.e. vancomycin, erythromycin, clindamycin, amoxicillin, tetracycline, rifampicin, ampicillin, ticarcillin and metronidazole/silver sulphadizine. Kirby Bauer disc diffusion method was used against test organisms and it was observed that all these antibiotics expressed significant activity against greater part of test organisms but few of them showed resistance to metronidazole/silver sulphadizine. In addition to this, different toothpastes encoded as TP-1, TP-2, TP-3, TP-4 and TP-5 were used at a concentration of 20 mg/mL in order to evaluate their activity against test organisms and it was observed that all these toothpastes showed significant activity against isolated bacteria. It was concluded that all these toothpastes contained fluoride which supports to avoid tooth decay and promote minty fresh breath. Furthermore, it was recommended that avoid usage of too much sweets, chocolates, candies especially in children/adults, and there must be a proper use of toothpastes twice a day at every stage of life. Keywords: Dental Caries, Pathogenic Bacteria, Antibiotics, Fluoride Toothpastes


Dairy ◽  
2020 ◽  
Vol 1 (3) ◽  
pp. 297-312
Author(s):  
Giacomo Lai ◽  
Rita Melillo ◽  
Massimo Pes ◽  
Margherita Addis ◽  
Antonio Fadda ◽  
...  

This study was conducted to assess, for the first time, the survival of the pathogenic bacteria Listeria monocytogenes, Salmonella spp., Escherichia coli O157:H7, and Staphylococcus aureus during the ripening of protected designation of origin (PDO) Pecorino Romano cheese. A total of twenty-four cheese-making trials (twelve from raw milk and twelve from thermized milk) were performed under the protocol specified by PDO requirements. Sheep cheese milk was first inoculated before processing with approximately 106 colony-forming unit (CFU) mL−1 of each considered pathogen and the experiment was repeated six times for each selected pathogen. Cheese composition and pathogens count were then evaluated in inoculated raw milk, thermized milk, and cheese after 1, 90, and 150 days of ripening. pH, moisture, water activity, and salt content of cheese were within the range of the commercial PDO Pecorino Romano cheese. All the cheeses made from raw and thermized milk were microbiologically safe after 90 days and 1 day from their production, respectively. In conclusion, when Pecorino Romano cheese is produced under PDO specifications, from raw or thermized milk, a combination of factors including the speed and extent of curd acidification in the first phase of the production, together with an intense salting and a long ripening time, preclude the possibility of growth and survival of L. monocytogenes, Salmonella spp., and E. coli O157:H7. Only S. aureus can be still detectable at such low levels that it does not pose a risk to consumers.


Author(s):  
Courage Kosi Setsoafia Saba ◽  
Akosua Bonsu Karikar ◽  
Enoch Yeleliere ◽  
Patrick Takyi ◽  
Stephen Wilson Kpordze

Microbial contamination of vended foods are of public health importance due to the potential of becoming a reservoir of foodborne pathogens and resistant strains of bacteria. This study looked at the presence of pathogenic bacteria in a popular Ready-To-Eat (RTE) traditional food, Fufu in Ghana. Sixty (60) Fufu samples were obtained from various food joints categorized as Opened, Semi-closed and Closed or Restaurants. Samples were processed and analyzed using standard bacteriological methods. The susceptibility profiles of the isolates were obtained by using the Kirby-Bauer disk diffusion method with the EUCAST guidelines with the five antibiotics. Prevalence of E. coli was 85% and Salmonella species was 68%. Microbial count of isolated E. coli ranged from 0 to 3×106 cfu/ml. There were no significant differences (p>0.05) among the different modes of operations. Fufu samples from Opened, Semi-closed and Closed joints were respectively contaminated with E. coli and Salmonella species as follows: 92%, 76%; 80%, 60% and 80%, 65%. The Salmonella species showed highest resistance to erythromycin (58.5%) and E. coli species were commonly resistant to Ceftazidime (88.2%) and Ceftriaxone (94.1%). All isolates were susceptible to nitrofurantoin. Multidrug resistance was detected among 27.5% of E. coli strains and 14.6% of Salmonella species. Fufu from the different eating joints in the Tamale Metropolis were substantially contaminated with multidrug resistant pathogens. The study recommends surveillance studies of resistant pathogens in foods, increased education and training of food vendors on sanitation, food handling and safety practices in the region.


2018 ◽  
Vol 39 (4) ◽  
pp. 1533
Author(s):  
Paola Bianca Barbosa Cavalin ◽  
Juan Josue Puño Sarmiento ◽  
Renata Katsuko Takayama Kobayashi ◽  
Gerson Nakazato ◽  
Armando Navarro Ocaña ◽  
...  

The presence of pathogenic microorganisms in meat products may result in foodborne diseases and economic losses to their producers. Small industries in the region of Londrina, Paraná, produce sausages that are commercialized in free fairs, small markets, bars, and restaurants in the city. Although these industries are inspected by the Municipal Inspection Service of Londrina, there are no data about the pathogenic microorganisms present in these products. The objective of this study was to investigate the presence of Salmonella spp. in sausages produced and sold in the region of Londrina, Paraná, and identify eae, bfp, stx1, stx2, hlyA, ipaH, elt, est, aggR, aap, and AA probe genes in Escherichia coli strains isolated from these samples. Forty-six samples of three types of sausages (fresh pork, Tuscan, and Calabresa) produced by four different producers (brands A, B, C, and D) were analyzed. Salmonella spp. was isolated from 13 (28.3%) and E. coli from 33 (71.3%) of the analyzed samples. Seven (53.8%) of 13 samples contaminated with Salmonella spp. were from brand A. Salmonella spp. contamination was the highest in the Tuscan sausage samples (8/17, 41.7%) when compared with the fresh pork sausage samples of all brands analyzed. E. coli was isolated from 12 of 13 samples contaminated with Salmonella spp. One sample of Calabresa sausage was contaminated with atypical enteropathogenic E. coli serotype O108:H9 that has the eae and hlyA genes. The results suggest contamination of the processing plant and/or raw meat used in the manufacture of sausages. A better inspection of the industries is required to ensure that Good Manufacturing Practices are followed by which the contamination of products by pathogenic bacteria can be prevented.


2019 ◽  
Vol 24 (1) ◽  
pp. 277-294
Author(s):  
Rocio Esperanza Patiño-Burbano ◽  
Ana Karina Carrascal ◽  
Jorge Luis Parra-Arango ◽  
José Luis Rodríguez-Bautista

Raw cow milk is considered one of the most important vehicles for pathogenic bacteria like Salmonella spp., Escherichia coli O157:H7, and Listeria monocytogenes. These three bacteria are responsible for foodborne diseases. Routine microbiological methods to detect these microorganisms in cow milk can be complicated and time consuming. The aim of this work was to evaluate a method to simultaneously detect Salmonella spp., Escherichia coli O157:H7, and Listeria monocytogenes in experimentally contaminated cow milk. The assessed method combined a standard microbiological culture step, using a pre-enrichment medium that favors the growth of the three focal microorganisms: SEL broth, followed by a single PCR assay. A total of 43 interference bacterial strains were used to evaluate the method’s specificity. The detection rate for the microbiological method with standard culture media was 10 UFC/mL, and that of the PCR detection, following pre-enrichment in SEL broth, was 10 UFC/mL for S. enterica and L. monocytogenes and between 1 and 5 UFC/mL for E. coli O157:H7. The PCR method showed specificity for the reference strains. Simultaneous detection by multiple PCR using SEL broth was successful for the detection of S. enterica, E. coli O157:H7, and L. monocytogenes in samples of experimentally contaminated cow milk, featuring both a high detection rate and a high specificity. This approach promises to be a feasible routine procedure when testing milk samples in industry and public health control setups.


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