Selective Preliminary Incubation for Gram-Negative Psychrotrophic Bacteria in Milk

1989 ◽  
Vol 52 (6) ◽  
pp. 396-398 ◽  
Author(s):  
R. D. BYRNE ◽  
J. R. BISHOP ◽  
M. L. MCGILLIARD
Keyword(s):  
Staphylococcus Aureus ◽  
Bacillus Cereus ◽  
Crystal Violet ◽  
Benzalkonium Chloride ◽  
Inhibitory Effects ◽  
Alkylaryl Sulfonate ◽  
Pseudomonas Fragi ◽  
Psychrotrophic Bacteria ◽  
Milk Samples ◽  
Pseudomonas Species

Milk samples containing crystal violet, benzalkonium chloride, crystal violet: benzalkonium chloride, or alkylaryl sulfonate were inoculated with each of Pseudomonas fluorescens, Pseudomonas fragi, Pseudomonas putida, Pseudomonas aeruginosa, Escherichia coli, Bacillus cereus, Staphylococcus aureus, and Streptococcus sp. Samples were incubated at 21°C for 18 h, and growth of the bacteria monitored to evaluate the inhibitory effects of the added reagents. Benzalkonium chloride proved to be the preferred inhibitor for selective incubation. It inhibited growth of Bacillus cereus, Staphylococcus aureus, and Streptococcus sp. at initial cell concentrations of 101, 102, and 104 per ml, while allowing uninhibited growth of all Pseudomonas species tested with an average increase of 3 logs. This finding is most important for the selective preliminary incubation necessary prior to milk quality assessment by plating and rapid instrumentation methods.

THE ROLE OF BACILLUS CEREUS IN SWEET CURDLING OF FLUID MILK

1974 ◽  
Vol 37 (5) ◽  
pp. 233-236 ◽  
Author(s):  
W. W. Overcast ◽  
Krishnaswamy Atmaram
Keyword(s):  
Bacillus Cereus ◽  
Pseudomonas Fluorescens ◽  
Raw Milk ◽  
Causative Organism ◽  
Refrigerated Storage ◽  
Pseudomonas Fragi ◽  
Milk Samples ◽  
Pseudomonas Species ◽  
Heat Activation

Twenty-eight percent of commercially pasteurized milk samples procured from various plants throughout Tennessee exhibited sweet-curdling within 10 days on refrigerated storage. Psychrotrophic Bacillus cereus was isolated as a causative organism from these milk samples. The isolates differed from the type culture organism only in their ability to grow and bring about sweet curd formation in skimmilk at refrigeration temperature. These isolates exhibited marked differences in their response to heat activation temperatures as well as to the initial excessive growth of Pseudomonas species in raw milk. Spores of three isolates exhibited greater activity after activation at 80 C for 15 sec than at the standard pasteurization temperature of 71.5 C for 15 sec. Excessive growth of Pseudomonas fragi or Pseudomonas fluorescens in raw skimmilk before processing had a stimulatory effect on two of three psychrotrophic Bacillus cereus isolates in combination with heat-activation especially with activation at 80 C for 15 sec.

Inhibitory Effects of Combinations of Chemicals on Escherichia coli, Bacillus cereus, and Staphylococcus aureus Biofilms during the Clean-in-Place Process at an Experimental Dairy Plant

2020 ◽  
Vol 83 (8) ◽  
pp. 1302-1306
Author(s):  
EUN-SEON LEE ◽  
JONG-HUI KIM ◽  
MI-HWA OH
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Citric Acid ◽  
Bacillus Cereus ◽  
Foodborne Pathogens ◽  
Combined Treatment ◽  
Food Additives ◽  
Inhibitory Effects ◽  
E Coli ◽  
And Staphylococcus Aureus

ABSTRACT In dairy plants, clean-in-place (CIP) equipment cannot be disassembled, making it difficult to clean the inner surface of pipes. In this study, the inhibitory effects of chemical agents on biofilms formed by three foodborne pathogens, Bacillus cereus, Escherichia coli, and Staphylococcus aureus, was evaluated in a dairy CIP system. The experiment was conducted on a laboratory scale. Each of the three bacteria (200 μL) was inoculated onto stainless steel (SS) chips (25 by 25 mm), and the effect of single cleaning agents was evaluated. Individual treatments with NaClO (30, 50, 100, and 200 ppm), NaOH (0.005, 0.01, 0.05, and 0.1%), citric acid (1, 3, 5, and 7%), and nisin (5, 10, 25, 50, 100, and 200 ppm) were used to clean the SS chip for 10 min. The most effective concentration of each solution was selected for further testing in a commercial plant. Simultaneous cleaning with 200 ppm of NaClO (10 min) and 7% citric acid (10 min) reduced the biofilms of B. cereus, E. coli, and S. aureus by 6.9, 7.0, and 8.0 log CFU/cm2, respectively. Both 7% citric acid and 0.1% NaOH were optimal treatments for E. coli. NaClO and citric acid are approved for use as food additives in the Republic of Korea. Our results revealed that a combined treatment with NaClO and citric acid is the most effective approach for reducing biofilms formed by common foodborne pathogens on CIP equipment. These findings can contribute to the production of safe dairy products. HIGHLIGHTS

Antibacterial Activity of Coumarins

2005 ◽  
Vol 60 (9-10) ◽  
pp. 693-700 ◽  
Author(s):  
Simone M. de Souza ◽  
Franco Delle Monache ◽  
Artur Smânia
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Bacillus Cereus ◽  
Coumarin Derivatives ◽  
Inhibitory Effects ◽  
Gram Positive Bacteria ◽  
Per Se ◽  
And Staphylococcus Aureus

Abstract The antibacterial activity of coumarin per se and other 45 coumarin derivatives was tested against strains of Bacillus cereus MIP 96016, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and Staphylococcus aureus ATCC 25923. The inhibitory effects of coumarins were affected by their substitution patterns. Osthenol (44) showed the most effective antibacterial activity against Gram-positive bacteria with MIC values ranging between 125 and 62.5 μg/ml. These results suggested that the prenyl chain of 44 at position 8 and the presence of OH at position 7 of the benzenic ring are required for the antibacterial activity against these strains.

Effect of pH on the antimicrobial activity of some triphenylmethane dyes

1978 ◽  
Vol 24 (6) ◽  
pp. 658-661 ◽  
Author(s):  
W. A. Moats ◽  
S. E. Maddox Jr.
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Bacillus Cereus ◽  
Crystal Violet ◽  
Brilliant Green ◽  
Enterobacter Aerogenes ◽  
Triphenylmethane Dyes ◽  
Gram Negative ◽  
Ethyl Violet ◽  
Ph Range

Four common dyes were tested as inhibitors of four types of bacteria over the pH range 5.0–9.0. Inhibition of the gram-negative types, Salmonella anatum and Enterobacter aerogenes, was markedly affected by the pH of the medium. These organisms tolerated concentrations of crystal violet and ethyl violet about 100-fold higher at pH 5.0 than at pH 9.0. Above pH 7.0 brilliant green (BG) and malachite green (MG) were precipitated as their respective carbinols and lost their inhibitory properties with these two organisms. Two gram-positive types, Staphylococcus aureus and Bacillus cereus, were more sensitive to dyes and results were less affected by pH. The carbinol forms of MG and BG were nearly as inhibitory to these organisms as the ionized forms.

The Effectiveness of Amoxicillin and Cefalexin in Two Species from Staphylococcus and Bacillus Isolated from Bovine Mastitis in Sudan

2019 ◽  
Author(s):  
Reem Rabie Mohammed Salih
Keyword(s):  
Bacillus Cereus ◽  
Bovine Mastitis ◽  
Bacillus Coagulans ◽  
Staph Aureus ◽  
Milk Samples ◽  
Sensitivity Tests ◽  
Bacillus Spp ◽  
Staphylococcus Spp

In this study 60 milk samples collected from mastitic cows to isolates and identify bacterial agents. The percentage of isolates was as follows: Staphylococcus spp 52%, Bacillus spp 26%, Enteroccocispp 3%; microccus 3%, Nesseria 2%, Branhamella 3%, Clostridium 1%, Bordetella 2%, Enterobacteria 3%, Aeromonas 4%, Fusobacterium 1%. In sensitivity tests used two antibiotics Amoxicillin and Cephalexin against two highest isolates in this study (Staph spp and Bacillus spp and found: Staph. aureus and Staph. hyicus were resistant to Amoxicllin and cephlaxin relatively, Bacillus coagulans and Bacillus cereus were susceptible to Amoxicllin and cephlaxin.

Effect of organic amendments on the decontamination potential of heavy metals by Staphylococcus aureus and Bacillus cereus in soil contaminated with spent engine oil

2019 ◽  
Vol 3 (5) ◽  
pp. 471-484
Author(s):  
Adeniyi Adeleye ◽  
Mohammed B. Yerima ◽  
Michael E. Nkereuwem ◽  
Victor O. Onokebhagbe ◽  
Peter G. Shiaka ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Staphylococcus Aureus ◽  
Bacillus Cereus ◽  
Organic Amendments ◽  
Engine Oil ◽  
Spent Engine Oil

scholarly journals Prevalence of methicillin-resistant Staphylococcus aureus and pattern of antimicrobial resistance in mastitis milk of cattle in Chitwan, Nepal

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Asmita Shrestha ◽  
Rebanta Kumar Bhattarai ◽  
Himal Luitel ◽  
Surendra Karki ◽  
Hom Bahadur Basnet
Keyword(s):  
Public Health ◽  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Subclinical Mastitis ◽  
World Health ◽  
Dairy Herds ◽  
Microbiological Analysis ◽  
Biochemical Tests ◽  
Methicillin Resistant ◽  
Milk Samples

Abstract Background The threat of methicillin-resistant Staphylococcus aureus (MRSA) exists globally and has been listed as a priority pathogen by the World Health Organization. One of the sources of MRSA emergence is livestock and its products, often raised in poor husbandry conditions. There are limited studies in Nepal to understand the prevalence of MRSA in dairy animals and its antimicrobial resistance (AMR) profile. A cross-sectional study was conducted in Chitwan, one of the major milk-producing districts of Nepal, from February 2018 to September 2019 to estimate the prevalence of MRSA in milk samples and its AMR profile. The collected milk samples (n = 460) were screened using the California Mastitis Test (CMT) and positive samples were subjected to microbiological analysis to isolate and identify S. aureus. Polymerase Chain Reaction (PCR) was used to identify the presence of the mecA gene and screen for MRSA. Results In total, 41.5% (191/460) of milk samples were positive in the CMT test. Out of 191 CMT positive milk samples, the biochemical tests showed that the prevalence of S. aureus was 15.2% (29/191). Among the 29 S. aureus isolates, 6.9% (2/29) were identified as MRSA based on the detection of a mecA gene. This indicates that that 1.05% (2/191) of mastitis milk samples had MRSA. The antibiotic sensitivity test showed that 75.9% (22/29) and 48.3% (14/29) S. aureus isolates were found to be sensitive to Cefazolin and Tetracycline respectively (48.3%), whereas 100% of the isolates were resistant to Ampicillin. In total 96.6% (28/29) of S. aureus isolates were multidrug-resistant (MDR). Conclusions This study revealed a high prevalence of S. aureus-mediated subclinical mastitis in dairy herds in Chitwan, Nepal, with a small proportion of it being MRSA carrying a mecA gene. This S. aureus, CoNS, and MRSA contaminated milk poses a public health risk due to the presence of a phenotype that is resistant to very commonly used antibiotics. It is suggested that dairy herds be screened for subclinical mastitis and treatments for the animals be based on antibiotic susceptibility tests to reduce the prevalence of AMR. Furthermore, future studies should focus on the Staphylococcus spp. to explore the antibiotic resistance genes in addition to the mecA gene to ensure public health.

Detection of virulence-associated genes in Staphylococcus aureus isolated from bovine clinical mastitis milk samples in Guangxi

2012 ◽  
Vol 44 (8) ◽  
pp. 1821-1826 ◽  
Author(s):  
Feng Li Yang ◽  
Xiao Shan Li ◽  
Xian Wei Liang ◽  
Xiu Fang Zhang ◽  
Guang Sheng Qin ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Clinical Mastitis ◽  
Milk Samples

scholarly journals Effects of Pre-Parturient Iodine Teat Dip Applications on Modulating Aversive Behaviors and Mastitis in Primiparous Cows

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1623
Author(s):  
Hannah N. Phillips ◽  
Ulrike S. Sorge ◽  
Bradley J. Heins
Keyword(s):  
Staphylococcus Aureus ◽  
Clinical Mastitis ◽  
Lactation Period ◽  
Early Lactation ◽  
Treatment Control ◽  
Intramammary Infections ◽  
Aureus Infection ◽  
Milk Samples ◽  
To Receive ◽  
Teat Dipping

Heifers and their human handlers are at risk for decreased welfare during the early lactation period. This experiment investigated pre-parturient teat dipping and parlor acclimation to reduce mastitis and aversive behaviors in early lactation heifers. Three weeks prior to calving, heifers were randomly assigned to receive either: (1) a weekly 1.0% iodine-based teat dip in the parlor (trained; n = 37) or (2) no treatment (control; n = 30). For the first 3 days of lactation, heifers were milked twice daily, and treatment-blinded handlers assessed behaviors and clinical mastitis. Aseptic quarter milk samples were collected within 36 h of calving and analyzed for pathogens. Control heifers had (OR ± SE) 2.2 ± 0.6 times greater (p < 0.01) odds of kicking during milking. Trained heifers had (OR ± SE) 1.7 ± 0.4 times greater (p = 0.02) odds of being very calm during milking, while control heifers had 2.2 ± 0.8 and 3.8 ± 2.1 times greater (p < 0.04) odds of being restless and very restless or hostile during milking, respectively. Quarters of control heifers had (OR ± SE) 5.4 ± 3.4 greater (p < 0.01) odds of intramammary Staphylococcus aureus infection, yet clinical mastitis was similar among treatments. The results indicate that teat dipping in the parlor weekly for 3 weeks before calving may alleviate some aversive milking behaviors and protect against early lactation S. aureus intramammary infections.

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