scholarly journals The synergistic effects of Lactobacillus acidophillus ROO52 and Lactobacillus bulgaricus LB-12 bacteriocins against E.coli O157 :H7 in milk

2014 ◽  
Vol 38 (2) ◽  
pp. 35-40
Author(s):  
Zina Saab Khudhir
Keyword(s):  
Lactobacillus Acidophilus ◽  
Synergistic Effects ◽  
Antimicrobial Effect ◽  
Average Diameter ◽  
Raw Milk ◽  
Inhibition Zone ◽  
Latex Agglutination ◽  
Lactobacillus Bulgaricus ◽  
Milk Samples ◽  
Test Kit

        The aims of this study to evaluate the antibacterial potential of standard strains (Lactobacillus acidophilus ROO52 and Lactobacillus bulgaricus LB-12) that produce bacteriocins against E.coli O157:H7 in raw milk.  Thirty raw milk samples randomly were collected weekly different markets of Baghdad city in order to investigate the prevalence of E.coli O157:H7 in milk. The prevalence of  E.coli O157:H7 in raw milk samples was  6 out 30 (20%) by using the modern chromogenic media with serological latex agglutination test kit. The average diameter of the inhibition zone of crude bacteriocin against  E .coli O157:H7 by using combination of 1:1 (v/v) of the Lactobacillus acidophillus ROO52 and  Lactobacillus bulgaricus LB-12was (14mm) ,while that produced by bacteriocins of Lactobacillus acidophillus ROO52 and  Lactobacillus bulgaricus LB-12  independently were 16 and 12mm respectively .L. delbrucekii ssp bulgaricus showed significantly (P<0.05) low antimicrobial effect against E.coli O157 :H7 .While the strongest antimicrobial effect was shown by Lactobacillus acidophilus ROO52. The bacteriocins of the reference strains used in this study did not result in an increase in inhibition when used in combination of 1:1 (v/v).

scholarly journals The synergistic bactericidal effects of bacteriocin and pressurization against E.coli O157:H7 in raw milk

2014 ◽  
Vol 38 (1) ◽  
pp. 15-23
Author(s):  
Najim Hadi Najim
Keyword(s):  
Antimicrobial Activity ◽  
Raw Milk ◽  
Inhibition Zone ◽  
Latex Agglutination ◽  
Pressure Level ◽  
Nutrient Broth ◽  
Whole Milk ◽  
Test Kit ◽  
Bactericidal Effects ◽  
Antimicrobial Effectiveness

Colonies of E.coli O157:H7 were isolated from 35 raw milk sample and their identification were confirmed based on biochemical reactions and both cultural and serological characteristics. Presumptive E.coli O157:H7 isolates obtained by selective plating on both CT-SMAC and Chromogenic agars were further tested serologically for the presence of both O157 and H7 antigenes using the commercial available latex agglutination test kit. The unhygienic practices in the production of milk in Al-Thahab Al- Abiedh , Abu-Graib, Al-Zedan and Khan Dharie were reflected on the highest significant (p<0.01)prevalence level of contamination with E.coli O157:H7 that appeared to be 80%, 80%, 60% and60% respectively. Homogenization pressure of 1000 psi and 2000 psi for five passes had significantly (p<0.05) influenced the inactivation degree of E.coli O157:H7 in both whole milk and nutrient broth. Milk homogenized at a pressure level of 3000 psi for three passes and 4000 psi for two passes resulted in a further increase of the antimicrobial effectiveness and produced an additional significant (p<0.05) reduction of E.coli O157:H7. Complete elimination (inactivation) of viable E.coli O157:H7 was achieved when cultured whole milk was homogenized at pressure level of 5000 psi for a single pass. Agar well diffusion bioassay was used for the evaluation of antimicrobial activity of the crude bacteriocin produced by L.acidophilus LA-K against E.coli O157:H7. Enterohaemorrhagic E.coli O157:H7 expressed its resistance to the crude bacteriocin since it did not show any inhibition zone around each well treated with bacteriocin. The average diameters of the inhibition zones of crude bacteriocin against stressed E.coli O157:H7 by pressurization at 4000 psi, 3000 psi, 2000 psi and 1000 psi were 14 mm, 12mm, 10mm and 8mm respectively. The homogenization pressure level (moderate or high) had significantly (p<0.05) influenced the inactivation degree of the crude bacteriocin against the stressed E.coli O157:H7 by pressurization. Quantitative measurement of crude bacteriocin antimicrobial activity was determined by using photometric or turbidometric method. The results revealed that no growth of stressed E.coli O157:H7 with no visible turbidity in the nutrient broth with bacteriocin that diluted to 1/2, 1/4 and 1/8 were observed. Bacteriocin that diluted to 1/8 which resulted in no visible turbidity after overnight of incubation at 37C° and gave an optical density reading of 1.448.

Detection of Bacillus cereus Diarrheal Enterotoxin in Raw and Pasteurized Milk

1997 ◽  
Vol 60 (11) ◽  
pp. 1391-1394 ◽  
Author(s):  
JOSEPH A. ODUMERU ◽  
ANN K. TONER ◽  
C. ANNE MUCKLE ◽  
MANSEL W. GRIFFITHS ◽  
JOHN A. LYNCH
Keyword(s):  
Bacillus Cereus ◽  
Raw Milk ◽  
Latex Agglutination ◽  
Moderate Temperature ◽  
Quality Analysis ◽  
Pasteurized Milk ◽  
Milk Samples ◽  
Enterotoxin B ◽  
Culture Supernatants

Raw and pasteurized milk samples submitted for routine quality analysis were screened for the presence of Bacillus cereus diarrheal enterotoxin (BDE) using the TECRA BDE Visual Immunoassay (VIA) kit. BDE was not detected in 298 raw milk samples tested by the TECRA VIA. B. cereus was isolated from 2 of 298 (0.7%) raw milk samples cultured. Culture supernatants from these isolates were positive for BDE in the TECRA VIA but negative in the Reverse Passive Latex Agglutination (RPLA) test for BDE. Forty-three of 112 (38.4%) pasteurized milk samples incubated at 10°C until their expiry dates were positive for BDE by the TECRA VIA. The same number of samples incubated at 4°C had no detectable levels of enterotoxin. B. cereus in the range of 103 to 106 CFU/ml was isolated from all BDE-positive pasteurized milk samples. BDE was detected in the culture supernatants of all the 43 isolates by TECRA VIA and in 30 of these isolates by RPLA. These results demonstrate that moderate temperature abuse of pasteurized milk may allow the growth of B. cereus and BDE production.

scholarly journals Carbohydrate Fermentation Profile and Physiological Studies of Lactic Acid Bacteria from Native Raw Cow Milk

2020 ◽  
pp. 83-93
Author(s):  
A. B. Adediran ◽  
S. Aforijiku
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Genomic Analysis ◽  
Proximate Analysis ◽  
Lactobacillus Bulgaricus ◽  
Cow Milk ◽  
Milk Samples ◽  
Probiotic Potential ◽  
Test Kit ◽  
Physiological Studies

The aim of this study was to identify and evaluate the physiological studies of lactic acid bacteria from native raw cow milk. Cow milk samples were collected purposively from four different locations in Ibadan. The proximate analysis, pH and acidity of the milk samples were examined using standard procedures. Lactic acid bacteria (LAB) were isolated, characterized, and identified using both morphological, biochemical test, and Analytical profile index (API) system. The identified LAB were subjected to various physiological conditions such as growth at different temperature (15, 30, 45°C), pH (4, 6, 8) and NaCl concerntrations (4, 6, and 8%).The heterotrophic counts ranged between 3.1 ×107to 4.2 ×107CFU/mL and lactic acid bacteria counts ranged from 2.2× 107 to 3.8 × 107 CFU/mL. Thirty-five LAB isolates were randomly picked and identified as Lactobacillus (57.15%), Streptococcus (14.29%), Leuconostoc (8.57%), Pediococcus (8.57%), Lactococcus (5.71%) and Enterococcus (5.71%). The LAB isolates were further identified as Lactobacillus plantarum, Leuconostoc mesenteriodes, Lactococcus lactis, Lactobacillus acidiophilus and Lactobacillus bulgaricus based on API 50 test kit, and were able to grow at different physiological paramaters. This study shows that Lactobacillus strains isolated from raw cow milk had better physiological attributes. These LAB could be recommended for further assessment such as evaluation of probiotic potential properties and genomic analysis.

Occurrence of Enterotoxic Staphylococcus aureus in Raw Milk from Yaks and Cattle in Mongolia

2007 ◽  
Vol 70 (7) ◽  
pp. 1726-1729 ◽  
Author(s):  
URANCHIMEG TSEGMED ◽  
GIOVANNI NORMANNO ◽  
MARIT PRINGLE ◽  
KAREL KROVACEK
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Products ◽  
Food Poisoning ◽  
Raw Milk ◽  
Latex Agglutination ◽  
Animal Origin ◽  
Foodborne Illnesses ◽  
First Report ◽  
Milk Samples ◽  
Milk And Dairy Products

Staphylococcal food poisoning is considered one of the leading foodborne illnesses in humans worldwide and is associated with contaminated foods of animal origin, such as milk and dairy products. In this study, we investigated the occurrence of staphylococci and the enterotoxigenic properties of Staphylococcus aureus isolated from raw milk from yaks (Bos mutus) and cattle in Mongolia. Staphylococci were isolated from 72 (74%) of the 97 raw milk samples. Of the samples containing staphylococci, 69% (50 of 72) were from yaks and 30.5% (22 of 72) were from cattle. S. aureus was detected in 10% of yak (7 of 72) and 21% of cattle (15 of 72) milk samples. Staphylococcal enterotoxin C was detected in 23% (5 of 22) of the S. aureus strains investigated, based on the reverse passive latex agglutination technique. Three of the five enterotoxigenic strains were from yaks and two were from cattle. None of the S. aureus strains tested produced staphylococcal enterotoxins A, B, or D. To our knowledge, this is the first report of the occurrence of staphylococci and enterotoxigenic S. aureus in milk from yaks and cattle in Mongolia.

scholarly journals The Difference of Antibacterial Power Between Cocoa Peel (Theobroma cacao) Extract 6% Compared to NaOCL 5% Againts Lactobacillus acidophilus

2021 ◽  
Vol 11 (2) ◽  
pp. 67
Author(s):  
Tamara Yuanita ◽  
Dian Agustin Wahjuningrum ◽  
Mega Selvia
Keyword(s):  
Lactobacillus Acidophilus ◽  
Average Diameter ◽  
Inhibition Zone ◽  
Diffusion Method ◽  
Control Group ◽  
Control Group Design ◽  
Post Test ◽  
The Difference ◽  
Peel Extract

Background: Lactobacillus acidophilus is a gram-positive rod-shaped bacteria which mostly causes chronic caries lesions. In the process of cavity preparation it is reported that it is not possible to remove all microorganisms and even bacteria can survive even after removal of the necrotic tissue. Efforts to stop the growth of these bacteria are by chemical cavity cleanser using a 5% NaOCl, but this material have disadvantages including irritating periradicular tissue, unpleasant odor, and toxicity. Due to its disadvantages, it is hoped that natural ingredients can be used as alternatives. Cocoa peel extract has active compounds of tannins, flavonoids, alkaloids, terpenoids, and saponins which have antibacterial ability with a concentration of 6% according to the non-toxic minimum kill concentration of Lactobacillus acidophilus. Purpose: To analyze the difference in antibacterial power between the extract of cocoa bark with a concentration of 6% compared to 5% NaOCl against Lactobacillus acidophilus. Methods: This study was a laboratory experimental in vitro with a post test-only control group design. Using diffusion method against Lactobacillus acidophilus grown in tubes containing BHIB, then cultured in a petridish which contains a nutrient agar and is divided into 2 parts extract cocoa peel extract 6% and NaOCl 5%, then each petridish given a paper disc that has been poured 10μl by each material, then incubated inthe incubator for 2x24 hours at 37oC and observe the diameter of the inhibition zone formed using a caliper. Results: The average diameter of the inhibition zone formed in the 6% cocoa peel extract was 11.8375 mm and NaOCl 5% was 26.0344 mm against Lactobacillus acidophilus. Conclusion: There is a difference in antibacterial power between 6% cocoa peel extract and 5% NaOCl against Lactobacillus acidophilus.

scholarly journals Bioassay activity of crude bacteriocin produced by Lactobacillus acidophilus isolate against cold stressed E.coli O157:H7

2012 ◽  
Vol 36 (0E) ◽  
pp. 268-273
Author(s):  
Najim Hadi Najim
Keyword(s):  
Lactobacillus Acidophilus ◽  
Inhibitory Concentration ◽  
Storage Temperature ◽  
Raw Milk ◽  
Latex Agglutination ◽  
Pathogenic Organism ◽  
Selective Enrichment ◽  
Cultural Isolation ◽  
Soft Cheese ◽  
Refrigeration Storage

The laboratory studies of the cultural isolation revealed that two isolates of Lactobacillus acidophilus were isolated from five soft cheese samples that were manufactured locally according to the farmers production procedure .Colonies of E.coli O157:H7 were isolated from raw milk samples by a conventional direct plating on selective enrichment CT-SMAC agar and tested serologically for the presence of O157 and H7 antigens using the commercial available latex agglutination kits .The results revealed that E.coli O157:H7 was resist to the crude bacteriocin that was extracted from L .acidophilus isolate NO.1 due to the nature of their cell wall, while when the outer membrane of E.coli O157:H7 was injured by cooling at 4°C for 6 hours , the permeation of bacteriocin to the cytoplasmic membrane was facilitated and caused inactivation and death of such pathogenic organism .The results revealed that no growth of E.coli O157:H7 with no visible turbidity in the nutrient broth with bacteriocin that diluted to 1\2 ,1\4 ,1\8 were observed .Bacteriocin that diluted to 1\8 had been recognized as the minimum inhibitory concentration of the bacteriocin.Both the dilution factor of bacteriocin and time exposure to bacteriocin at refrigeration storage temperature of milk had a significant (P˂0.05) influence on its antimicrobial potency against the viability of stressed E.coli O157:H7 from minutes 30 to 120 .The viability of E.coli O157:H7 subjected to bacteriocin that diluted 10 times(1:10) in both raw and sterile milk was efficiently eliminated after 90 minutes and 60 minutes of exposure at refrigeration temperature respectively.

scholarly journals Prevalence of Mastitis and Antibiotic Resistance of Bacterial Isolates from CMT Positive Milk Samples Obtained from Dairy Cows, Camels, and Goats in Two Pastoral Districts in Southern Ethiopia

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1530
Author(s):  
Amanuel Balemi ◽  
Balako Gumi ◽  
Kebede Amenu ◽  
Sisay Girma ◽  
Muuz Gebru ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Dairy Cows ◽  
Raw Milk ◽  
Multidrug Resistant ◽  
Southern Ethiopia ◽  
Resistant Bacteria ◽  
Coagulase Negative Staphylococcus ◽  
Bacterial Isolates ◽  
E Coli ◽  
Milk Samples

A study was carried out from August 2017 to February 2018 on lactating dairy cows, one-humped dromedary camels, and goats to determine mastitis in the Bule Hora and Dugda Dawa districts of in Southern Ethiopia. Milk samples from 564 udder quarters and udder halves from 171 animals consisting of 60 dairy cows, 51 camels, and 60 goats were tested for mastitis. Sixty-four positive udder milk samples were cultured, and bacterial mastitis pathogens were isolated and identified. The antibiotic resistance of bacterial isolates from milk with mastitis was tested against nine antimicrobials commonly used in the study area. Cow- and quarter-level prevalence of mastitis in dairy cows, camels, and goats was 33.3%, 26.3%, and 25% and 17.6%, 14.5%, and 20%, respectively. In cattle, the prevalence was significantly higher in Dugda Dawa than in Bule Hora. Major bacterial isolates were coagulase-negative Staphylococcus species (39.1%), S. aureus (17.2%), S. hyicus (14.1%), and S. intermedius and Escherichia coli (9.4% each). In camels, udder abnormality and mastitis were significantly higher in late lactation than in early lactation. Mastitis tends to increase with parity in camels. E. coli isolates were highly resistant to spectinomycin, vancomycin, and doxycycline, whereas most S. aureus isolates were multidrug-resistant. Most of the rural and periurban communities in this area consume raw milk, which indicates a high risk of infection with multidrug-resistant bacteria. We recommend a community-focused training program to improve community awareness of the need to boil milk and the risk of raw milk consumption.

scholarly journals Aceitação sensorial e caracterização de frozen yogurt de leite de cabra com adição de cultura probiótica e prebiótico

2009 ◽  
Vol 39 (9) ◽  
pp. 2595-2600 ◽  
Author(s):  
Larissa de Lima Alves ◽  
Neila Silvia Pereira dos Santos Richards ◽  
Larissa Vargas Becker ◽  
Diego Fontana de Andrade ◽  
Liana Inês Guidolin Milani ◽  
...  
Keyword(s):  
Lactobacillus Acidophilus ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Bulgaricus ◽  
Bifidobacterium Animalis ◽  
Frozen Yogurt

O leite de cabra é recomendado para pessoas intolerantes ao leite de vaca e/ou portadoras de desordens gastrintestinais. frozen yogurt elaborado a partir de iogurte de leite de cabra foi acrescido de 1% de prebiótico (inulina), 0,25% de cultura starter (Streptococcus thermophilus e Lactobacillus bulgaricus) e 0,25% de cultura probiótica (Bifidobacterium animalis e Lactobacillus acidophilus) para verificar seu potencial probiótico (após sete e 120 dias de armazenamento), sua qualidade físico-química e sua aceitação sensorial. Durante a estocagem, houve redução de células viáveis da flora microbiana, principalmente dos probióticos. Ainda assim, o produto apresenta potencialidade probiótica pela soma de B. animalis e L. acidophilus atingir o mínimo desejável até o fim do armazenamento. Os valores de extrato seco total (26,6±0,2%), proteína (3,0±0,2), gordura (2,6±0,1%), pH (5,5±0,01) e ácido láctico (0,2±0,01%) encontram-se semelhantes aos relatados em outros trabalhos para o mesmo produto. A avaliação sensorial foi realizada por 50 provadores não treinados em teste com escala hedônica de sete níveis e intenção de compra. O produto recebeu bons escores para aparência global, cor, aroma e sabor; já textura e sabor residual obtiveram menores índices de aceitação. Na intenção de compra, 61% dos avaliadores declararam que comprariam o produto, contra 39% que não comprariam. Nessas condições, demonstra-se a viabilidade de elaboração de frozen yogurt de leite caprino acrescido de pre- e probióticos.

scholarly journals MOLECULAR DETECTION AND CHARACTERIZATION OF STAPHYLOCOCCUS AUREUS ISOLATED FROM RAW MILK SOLD IN DIFFERENT MARKETS OF BANGLADESH

2017 ◽  
Vol 14 (2) ◽  
pp. 277-282 ◽  
Author(s):  
M. A. Islam ◽  
S. M. L. Kabir ◽  
M. T. Rahman
Keyword(s):  
Molecular Detection ◽  
Culture Media ◽  
Raw Milk ◽  
Rrna Gene ◽  
Biochemical Tests ◽  
Selective Media ◽  
Milk Samples ◽  
Antimicrobial Sensitivity ◽  
Antimicrobial Sensitivity Test

The study was intended for molecular detection of S. aureus isolated from raw cow’s milk. A total of 20 milk samples were collected from different upazila markets of Jamalpur, Tangail, Kishoreganj and Netrokona districts of Bangladesh. Milk samples were cultured onto various culture media for the isolation of bacteria. The isolated bacteria were identified by studying cultural properties on different selective media, biochemical tests, and finally by PCR. Out of 20 samples, 15 (75%) milk samples were found to be positive for S. aureus. S. aureus specific 16S rRNA gene was amplified from all isolates and identified as S. aureus. Antimicrobial sensitivity test was carried out to ascertain the susceptibility of the organism to various antibiotics. Its results showed that the S. aureus isolates were resistant to amoxicillin (100%), erythromycin (73.33%) and tetracycline (73.33%) but sensitive to azithromycin (93.33%), ciprofloxacin (93.33%), gentamicin (100%), norfloxacin (86.67%) and streptomycin (86.67%).

scholarly journals Bulk tank somatic cell count and associated microbial quality of milk from selected dairy cattle herds in Oyo State, Nigeria

2018 ◽  
Vol 7 (2) ◽  
Author(s):  
Olufemi Olatoye ◽  
Adesola Amosun ◽  
Uzo Ogbu ◽  
Yemi Okunlade
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Health Management ◽  
Development Program ◽  
Raw Milk ◽  
Human Consumption ◽  
Quality And Safety ◽  
Milk Samples ◽  
California Mastitis Test

Improvement of traditional and nomadic milk production through dairy development program in Nigeria requires routine quality and safety monitoring of milk both at herd level and milk collection centers. A total of 411 bulk raw milk samples aseptically obtained from Ibarapa, Oyo and Oke-Ogun industrial milk collection centers were subjected to California Mastitis Test (CMT), Bulk Somatic Cell Count (BSCC) and bacteriological analysis for assessment of quality and safety of milk from the herds. One hundred and seven (26.0%) of the samples were CMT positive, while 74.0% were negative to CMT. The overall mean BSCC, TAC and TCC were 1.27×103 ± cells/mL, 1.12×103± 34 cfu/mL, 97.8±9.8 cfu/mL in the CMT negative milk samples while for the strong positive samples the mean BSCC, TAC and TCC were 4.33×106 ± cells/mL, 2.35×106 ± 453 cfu/mL, 189.3±41.1 cfu/mL respectively; these were higher than the Pasteurized Milk Ordinance acceptable limits. Positive correlation was found between CMT scores and bacterial contamination and between CMT scores and SCC was recorded. About 26.0% of the samples with positive CMT could be considered unsafe due to strong correlation with microbial contamination that could result in milk borne zoonoses and public health hazards. However, a greater proportion (76.9%) of the milk with negative CMT scores could be safe for human consumption after post-harvest pasteurization. Consequently, there is need to improve handling, environmental and milking hygiene; as well as proper herd and udder health management to improve quality and safety of Nigeria dairy products.

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