Probabilistic modelling of Escherichia coli concentration in raw milk under hot weather conditions

In recent years, the incidence of foodborne diseases caused by shiga toxin-producing Escherichia coli (STEC) has increased globally. For this reason, within the specific regional control plan for the detection of STEC in food products in Italy, the presence of STEC in unpasteurized milk cheeses was investigated. In total 203 samples obtained from March 2011 to December 2013 were analysed, with two standard methods (ISO 16654:2001 and ISO 13136:2012). Two strains of E. coli O157 were isolated (2/161, 1.2%) but did not carry any virulence-associated genes and 22 stx-positive samples (22/146, 15.1%) were detected in enrichment cultures, mostly from ovine cheeses. Only two strains isolated from different ovine cheeses carried stx gene and none of these was eae-positive. This study confirms the presence of stx-positive E. coli and suggests that this type of food cannot be excluded as a potential vehicle of STEC.

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Indoor Air Quality (IAQ): Accuracy of Natural Ventilation for Temperature, Air Flow Rate and Relative Humidity (RH) in School Building Classrooms

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i3.9.15271 ◽

2018 ◽

Vol 7 (3.9) ◽

pp. 42

Author(s):

Norsafiah Norazman ◽

Adi Irfan Che Ani ◽

Nor Haslina Ja’afar ◽

Muhamad Azry Khoiry

Keyword(s):

Air Quality ◽

Relative Humidity ◽

Indoor Air Quality ◽

Indoor Air ◽

Natural Ventilation ◽

Air Flow ◽

Weather Conditions ◽

Potential Health ◽

The Hours ◽

Hot Weather

Indoor Air Quality (IAQ) is an essential matter in achieving students’ satisfaction for the learning process. Building’s orientation is a factor that may encourage sufficient natural ventilation for the classroom occupants. Inadequate ventilation is an issue for most existing classrooms. The purpose of this paper is to analyze the accuracy of natural ventilation in classrooms. Therefore, experimental on 20 classrooms has been conducted by using Multipurpose Meter at secondary school buildings in Malaysia. The findings indicated that the accuracy of natural ventilation testing was below the permissible limits throughout the hours monitored, thus this may cause potential health hazards to the students. Temperature and air flow rates were lower than 23 °C and 0.15 m/s respectively, it fulfilled the basic requirements as a standard learning environment. However, measurements taken showed the overall relative humidity (RH) in the classrooms can be categorized as acceptable with 40% to 70% range. On the basis of these findings, it is evident that naturally ventilated classrooms are important especially due to energy efficiency, whereas mechanical ventilation should only be installed as an alternative under extremely hot weather conditions.

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Characteristics of Shiga Toxin–Producing Escherichia coli Isolated from Swiss Raw Milk Cheese within a 3-Year Monitoring Program

Journal of Food Protection ◽

10.4315/0362-028x-73.1.88 ◽

2010 ◽

Vol 73 (1) ◽

pp. 88-91 ◽

Cited By ~ 36

Author(s):

C. ZWEIFEL ◽

N. GIEZENDANNER ◽

S. CORTI ◽

G. KRAUSE ◽

L. BEUTIN ◽

...

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Monitoring Program ◽

Raw Milk ◽

Health Impact ◽

Toxin Gene ◽

Genes Encoding ◽

Raw Milk Cheese ◽

Human Infections ◽

Hard Cheese

Food is an important vehicle for transmission of Shiga toxin–producing Escherichia coli (STEC). To assess the potential public health impact of STEC in Swiss raw milk cheese produced from cow's, goat's, and ewe's milk, 1,422 samples from semihard or hard cheese and 80 samples from soft cheese were examined for STEC, and isolated strains were further characterized. By PCR, STEC was detected after enrichment in 5.7% of the 1,502 raw milk cheese samples collected at the producer level. STEC-positive samples comprised 76 semihard, 8 soft, and 1 hard cheese. By colony hybridization, 29 STEC strains were isolated from 24 semihard and 5 soft cheeses. Thirteen of the 24 strains typeable with O antisera belonged to the serogroups O2, O22, and O91. More than half (58.6%) of the 29 strains belonged to O:H serotypes previously isolated from humans, and STEC O22:H8, O91:H10, O91:H21, and O174:H21 have also been identified as agents of hemolytic uremic syndrome. Typing of Shiga toxin genes showed that stx1 was only found in 2 strains, whereas 27 strains carried genes encoding for the Stx2 group, mainly stx2 and stx2vh-a/b. Production of Stx2 and Stx2vh-a/b subtypes might be an indicator for a severe outcome in patients. Nine strains harbored hlyA (enterohemorrhagic E. coli hemolysin), whereas none tested positive for eae (intimin). Consequently, semihard and hard raw milk cheese may be a potential source of STEC, and a notable proportion of the isolated non-O157 STEC strains belonged to serotypes or harbored Shiga toxin gene variants associated with human infections.

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Occurrence of toxigenic Escherichia coli in raw milk cheese in Brazil

Arquivo Brasileiro de Medicina Veterinária e Zootecnia ◽

10.1590/s0102-09352007000200035 ◽

2007 ◽

Vol 59 (2) ◽

pp. 508-512 ◽

Cited By ~ 27

Author(s):

B.R. Paneto ◽

R.P. Schocken-Iturrino ◽

C. Macedo ◽

E. Santo ◽

J.M. Marin

Keyword(s):

Escherichia Coli ◽

Polymerase Chain Reaction ◽

Antimicrobial Agents ◽

Raw Milk ◽

Diffusion Method ◽

Chain Reaction ◽

Disk Diffusion Method ◽

E Coli ◽

Polymerase Chain ◽

Raw Milk Cheese

The occurrence of toxigenic Escherichia coli in raw milk cheese was surveyed in Middle Western Brazil. Fifty samples of cheese from different supermarkets were analyzed for E.coli. The isolates were serotyped and screened for the presence of verotoxigenic E. coli (VTEC) and enterotoxigenic E. coli (ETEC) by Polymerase Chain Reaction (PCR). The susceptibility to thirteen antimicrobial agents was evaluated by the disk diffusion method. E.coli were recovered from 48 (96.0%) of the samples. The serogroups identified were O125 (6.0%), O111 (4.0%), O55 (2.0%) and O119 (2.0%). Three (6.0%) and 1(2.0%) of the E.coli isolates were VTEC and ETEC, respectively. Most frequent resistance was observed to the following antimicrobials: cephalothin (60.0%), nalidixic acid (40.0%), doxycyclin (33.0%), tetracycline (31.0%) and ampicillin (29.0%).

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Incidence of Escherichia coli O157 in raw milk and white pickled cheese manufactured from raw milk in Turkey

Food Control ◽

10.1016/s0956-7135(03)00121-x ◽

2004 ◽

Vol 15 (6) ◽

pp. 453-456 ◽

Cited By ~ 18

Author(s):

Ö Öksüz ◽

M Arici ◽

S Kurultay ◽

T Gümüs

Keyword(s):

Escherichia Coli ◽

Raw Milk ◽

Escherichia Coli O157

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The influence of the climatology of the semi-arid from Alagoas-Brazil on the raw milk microbiota

International Journal of Food and Allied Sciences ◽

10.21620/ijfaas.2017127-35 ◽

2017 ◽

Vol 3 (1) ◽

pp. 27

Author(s):

Ticiano Gomes do Nascimento ◽

Euridice Farias Falcão ◽

Maria Cristina Delgado da Silva ◽

Josicleide Nascimento Oliveira Silvino ◽

Pierre Barnabé Escodro ◽

...

Keyword(s):

Escherichia Coli ◽

Thermal Comfort ◽

Vegetation Index ◽

Raw Milk ◽

Climatic Conditions ◽

The State ◽

Maximum Temperature ◽

Climatic Data ◽

Microbiological Analysis ◽

Semi Arid

This study aimed to evaluate the influence of the climatology of the semi-arid from Alagoas-Brazil on the raw milk microbiota in semi-arid area of the 07 micro-regions of the State of Alagoas of Alagoas, Brazil. The climatic data were extracted from National Institute of Meteorology from the Brazilian government. The raw milk was collected after the dairy cow milking process in 12 small rural associations of the semi-arid from the State of Alagoas, during the 4 seasons and the raw milk was carried out procedures of sampling, transportation and microbiological analysis. A total of 58 samples were counted coliforms at 45°C, Escherichia coli and coagulase-positive Staphylococcus. Only 02 rural associations presented low levels of microbiological contamination, which were located in areas of climatic conditions and parameters of thermal comfort index and vegetation index favorable, but 10 rural associations presented high counting of coliforms at 45°C, Escherichia coli. The climatologic parameters (maximum temperature, atmospheric pressure), bovine comfort thermal index and vegetation index have showed to influence the growth of the coliforms at 45°C and Escherichia coli with high incidence during the summer weather. The precipitation parameter, bovine thermal comfort and vegetation index have displayed to influence coagulase-positive Staphylococcus counting especially during the period between the summer end and the autumn beginning seasons. New Actions, and Rural Education and Health Programs should be implemented as politics of Food Safety. New strategies and programs for dissemination more effective on the risks of transmission of pathogens and Foodborne Diseases are necessary as the part of emergence politics of the health and education areas. Regulatory Actions should be encouraged within the processes that improve the quality control of raw milk as well its bioproducts, with professional assistance relevant in agriculture area.

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