THE DEVELOPMENT OF BACTERIAL POPULATIONS IN MILK

1957 ◽  
Vol 3 (2) ◽  
pp. 203-213 ◽  
Author(s):  
T. Gibson ◽  
Y. Abd-El-Malek
Keyword(s):  
Heat Treatment ◽  
Bacillus Cereus ◽  
Raw Milk ◽  
Coagulase Negative Staphylococci ◽  
Bacterial Populations ◽  
Gram Negative ◽  
Streptococcus Lactis ◽  
Plate Counts ◽  
Group A ◽  
Dominant Bacteria

The dominant bacteria in different classes of milk have been identified by taking samples of the colonies on quantitatively inoculated plates. Many of the bacteria that occur commonly in milk find it a relatively unfavorable medium. In the temperature range 10°–22 °C. the organisms that multiply actively are the Streptococcus lactis group, a species of Leuconostoc, coagulase-negative staphylococci, and Gram-negative rods (chiefly Alcaligenes viscosus and fluorescent and non-fluorescent pseudomonads). Plate counts of organisms that resist pasteurization for 30 minutes at 63 °C. are unsuitable for demonstrating the multiplication of Leuconostoc or Alcaligenes tolerans, which show variable and frequently low rates of survival in the heat treatment. In laboratory-pasteurized milk incubated without recontamination, the surviving organisms, unlike the populations of raw milk, do not show distinctly the effects of a differential selection. The only thermoduric organism that was found to produce rapid deterioration of milk is Bacillus cereus (including B. mycoides).

Determination of Viable Bacterial Populations in Raw Milk within 20 Minutes by Using a Direct Epifluorescent Filter Technique

1997 ◽  
Vol 60 (7) ◽  
pp. 874-876 ◽  
Author(s):  
CLAUDE P. CHAMPAGNE ◽  
NANCY J. GARDNER ◽  
JULIE FONTAINE ◽  
JACQUES RICHARD
Keyword(s):  
Raw Milk ◽  
Plate Count ◽  
Bacterial Populations ◽  
Filter Technique ◽  
Milk Samples ◽  
Standard Plate ◽  
Plate Counts ◽  
Direct Epifluorescent Filter Technique ◽  
Triton X

The results from a shortened procedure for the direct epifluorescent filter technique (DEFT) determination of viable bacterial populations in raw milk were compared to standard plate counts. Shortening the prefiltration trypsin-Triton X-100 incubation period from 10 to 3 min enabled the completion of the analysis within 20 min. The short DEFT method results had a correlation coefficient (r) of 0.81 with plate counts. With respect to precision, the average difference between values of duplicate plate count analyses was 0.16 log units; that of the short DEFT was 0.14 log units. The slopes of the regressions equations were less than 1, indicating that a direct correlation is not achieved. Short DEFT values were 0.17 log units higher than those of plate counts on milk samples containing less than 10,000 CFU/ml. For milk samples containing counts over 10,000 CFU/ml, short DEFT values averaged only 0.05 log units above plate count readings. Daily preparation of the stain appears unnecessary since acridine orange solutions stored for up to 2 days at 4°C did not produce results significantly (P > 0.05) different from those obtained with fresh solutions. The short DEFT method has potential for the assessment of the bacteriological quality of raw milk in tanker deliveries.

scholarly journals Major Mammary Pathogens as Contributors to Total Bacterial Counts in Raw Milk

2009 ◽  
Vol 78 (3) ◽  
pp. 455-461 ◽  
Author(s):  
Dušan Ryšánek ◽  
Monika Zouharová ◽  
Vladimír Babák
Keyword(s):  
Geometric Mean ◽  
Raw Milk ◽  
Coliform Bacteria ◽  
Geometric Means ◽  
Gram Negative ◽  
Bacterial Counts ◽  
Standard Plate ◽  
Plate Counts ◽  
Positive Correlations ◽  
Environmental Pathogens

The purpose of this study was to assess the contribution of major mammary pathogens, as well as of coliform and Gram-negative non-coliform bacteria to standard plate counts (SPCs) of bulk tank milk samples (BTMSs). Randomly selected anonymous BTMSs were collected from 268 dairy herds (with approximately 29,000 cows) in the Czech Republic during 2007. The most frequently detected pathogens were found to be E. faecalis (16.1%; geometric mean 9.8 × 102 CFU/ml) and S. uberis (13.6%; 9.0 × 102 CFU/ml). Highly significant positive correlations (P < 0.01) between the bacterial counts of the dominant pathogens and the relevant SPC were found for E. faecalis and S. dysgalactiae, as were significant correlations (P < 0.05) for S. uberis, E. faecium, and S. aureus. Highly significant positive correlations (P < 0.01) were found between SPC and coliform count and between SPC and Gram-negative non-coliform bacteria count. The results suggest, therefore, a recent dominance of environmental pathogens especially streptococci and enterococci, over contagious mammary pathogens in BTMSs. The geometric means of SPC in BTMSs with mammary pathogen (7.7 × 104 CFU/ml for environmental; 7.4 × 104 CFU/ml for contagious pathogens) exceed significantly (P < 0.05) the geometric means of SPC of pathogen free BTMSs (4.4 × 104 CFU/ml). This study revealed that the major mammary pathogens contribute significantly to SPCs of BTMSs.

scholarly journals Effects of topical erythromycin on ecology of aerobic cutaneous bacterial flora.

1996 ◽  
Vol 40 (11) ◽  
pp. 2598-2604 ◽  
Author(s):  
B R Vowels ◽  
D S Feingold ◽  
C Sloughfy ◽  
A N Foglia ◽  
N Konnikov ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Resistance Gene ◽  
Bacterial Flora ◽  
Vehicle Group ◽  
Erythromycin Resistance ◽  
Coagulase Negative Staphylococci ◽  
Gram Negative ◽  
Group A ◽  
Baseline Values ◽  
Study Sites

We have demonstrated previously that application of topical erythromycin, an antibiotic commonly used for the treatment of acne, results in an increased density of cutaneous erythromycin-resistant (Emr) coagulase-negative staphylococci; however, it is unknown if this increase results in an overall higher density of total cutaneous staphylococci or if upon cessation of erythromycin use, Emr coagulase-negative staphylococci remain at an increased density compared with the pretreatment density. To investigate this, 2% erythromycin or vehicle was applied to each subject's forehead (n = 225) twice a day by laboratory personnel for a period of 6 weeks. Samples were obtained for culture from the forehead, anterior nares, and back of the subjects at baseline and at weeks 6, 9, and 12 of the study. Cultures were performed on differential media. Plates into which erythromycin was incorporated (8 micrograms/ml) were used to identify Emr coagulase-negative staphylococci. The species of all Emr coagulase-negative staphylococci were determined, and an antibiogram for 16 antibiotics was obtained. The baseline prevalence of Emr coagulase-negative staphylococci on the forehead and nose was about 80% at the two study sites, whereas that on the back was 50%. The baseline density of Emr coagulase-negative staphylococci on the forehead, nose, and back was approximately 20% of the total flora. Following 6 weeks of erythromycin treatment, the prevalence of Emr coagulase-negative staphylococci on the forehead and nose was nearly 100% and the densities were 73 and 62%, respectively; the prevalence and density for the back were 78 and 42%, respectively. The most prevalent erythromycin resistance gene expressed by the Emr coagulase-negative staphylococci was ermC. There was no increase in the numbers of Staphylococcus aureus, gram-negative rods, or yeasts, nor was there increased resistance to any other antibiotic except clindamycin. The density of total aerobic organisms also remained static. There were no changes in the prevalence or density of Emr coagulase-negative staphylococci in the vehicle group. A statistically significant decrease in the prevalence and density of Emr coagulase-negative staphylococci in the erythromycin group was observed within 3 weeks posttreatment and by 6 weeks posttreatment, the prevalence and density returned to baseline values. These data demonstrate that the increased prevalence and density of Emr coagulase-negative staphylococci as a result of topical 2% erythromycin use are transient on both population and individual levels.

scholarly journals The hygienic quality of raw reindeer milk

Rangifer ◽  
2004 ◽  
Vol 24 (2) ◽  
pp. 67-70 ◽  
Author(s):  
Joanna Kurki ◽  
Anna Pitkälä ◽  
Mauri Nieminen
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Bacillus Cereus ◽  
Raw Milk ◽  
Total Bacterial Count ◽  
Coagulase Negative Staphylococci ◽  
Bulk Milk ◽  
Hygienic Quality

The somatic cell count (SCC) and total bacterial count (TBC) as well as the presence of major food-borne pathogens and udder pathogens in reindeer raw milk were studied. Two groups of 4 female reindeer were milked on alternate days for six weeks. A milk sample from each quarter was taken before milking and of the bulk milk at the end of milking. Micrococcus sp. was observed in one, Staphylococcus aureus in one and coagulase-negative staphylococci in five of the quarter samples (n=318). In the bulk milk (n=19) TBC varied between 700 and 1 700 000 cfu (colony forming units)/ml and SCC between 52 000 and 183 000 cells/ml. No Bacillus cereus, S. aureus or Listeria monocytogenes were detected in the bulk milk, but Escherichia coli and Enterobacteriaceae were found in 5 bulk milk samples. According to the bacteriological examination the udder health of the reindeer was good. Indicative information on the SCC of healthy reindeer was obtained. None of the common potential food-poisoning bacteria were found in raw milk. There was great variation in the bulk milk TBC and the average TBC was rather high (ca. 300 000 cfu/ml). The hygienic quality of raw reindeer milk makes it well suited for food manufacture. However, the results indicate that the milking conditions may be crucial for the quality of raw milk.Abstract in Finnish / Yhteenveto:Tutkimuksen kohteena oli poron raakamaidon solupitoisuus ja kokonaispesäkeluku sekä tärkeimpien elintarvike- ja utarepatogeenien esiintyminen raakamaidossa. Kaksi 4 vaatimen ryhmää lypsettiin vuoropäivinä 6 viikon ajan. Ennen lypsyä vaatimista otettiin vedinkohtaiset näytteet ja lypsyn päätyttyä näyte yhteismaidosta. Micrococcus sp. todettiin yhdessä, Staphylococcus aureus yhdessä ja koagulaasinegatiivisia stafylokokkeja viidessä vedinkohtaisessa näytteessä (n=318). Yhteismaitonäytteiden (n=19) kokonaispesäkeluvut vaihtelivat välillä 700-1 700 000 pmy (pesäkkeitä muodostava yksikkö)/ml ja somaattisten solujen määrät välillä 52 000-183 000 kpl/ml. Yhteismaitonäytteissä ei todettu Bacillus cereus-, S. aureus- eikä Listeria monocytogenes -bakteereita, mutta viidessä näytteessä todettiin Enterobacteriaceae-heimon bakteereita ja Escherichia coli -bakteereita. Bakteeriviljelyjen perusteella vaadinten utareterveys oli hyvä. Terveiden vaadinten maidon solupitoisuudesta saatiin suunta-antavaa tietoa. Raakamaidossa ei todettu yleisimpiä potentiaalisia ruokamyrkytysten aiheuttajia. Yhteismaidon kokonaispesäkeluvuissa esiintyi suurta vaihtelua ja niiden keskiarvo oli melko korkea (n. 300 000 pmy/ml). Poron raakamaito on hygieeniseltä laadultaan hyvää elintarvikkeiden raakaainetta. Tulokset antavat kuitenkin viitteitä, että itse lypsytapahtuma on porollakin avainasemassa raakamaidon laatuun vaikuttavana tekijänä.

scholarly journals National Temporal Trend Analysis of Infective Endocarditis among Patients Infected with HIV in Spain (1997–2014): A Retrospective Study

2019 ◽  
Vol 8 (8) ◽  
pp. 1167 ◽  
Author(s):  
Maria Fe Muñoz-Moreno ◽  
Pablo Ryan ◽  
Alejandro Alvaro-Meca ◽  
Jorge Valencia ◽  
Eduardo Tamayo ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Infective Endocarditis ◽  
Hospital Admissions ◽  
Downward Trend ◽  
Coagulase Negative Staphylococci ◽  
Data Set ◽  
Gram Negative ◽  
Epidemiological Trend ◽  
Incidence And Mortality ◽  
Significant Downward Trend

Background: People living with human immunodeficiency virus (HIV) (PLWH) form a vulnerable population for the onset of infective endocarditis (IE). We aimed to analyze the epidemiological trend of IE, as well as its microbiological characteristics, in PLWH during the combined antiretroviral therapy era in Spain. Methods: We performed a retrospective study (1997–2014) in PLWH with data obtained from the Spanish Minimum Basic Data Set. We selected 1800 hospital admissions with an IE diagnosis, which corresponded to 1439 patients. Results: We found significant downward trends in the periods 1997–1999 and 2008–2014 in the rate of hospital admissions with an IE diagnosis (from 21.8 to 3.8 events per 10,000 patients/year; p < 0.001), IE incidence (from 18.2 to 2.9 events per 10,000 patients/year; p < 0.001), and IE mortality (from 23.9 to 5.5 deaths per 100,000 patient-years; p < 0.001). The most frequent microorganisms involved were staphylococci (50%; 42.7% Staphylococcus aureus and 7.3% coagulase-negative staphylococci (CoNS)), followed by streptococci (9.3%), Gram-negative bacilli (8.3%), enterococci (3%), and fungus (1.4%). During the study period, we found a downward trend in the rates of CoNS (p < 0.001) and an upward trends in streptococci (p = 0.001), Gram-negative bacilli (p < 0.001), enterococci (p = 0.003), and fungus (p < 0.001) related to IE, mainly in 2008–2014. The rate of community-acquired IE showed a significant upward trend (p = 0.001), while the rate of health care-associated IE showed a significant downward trend (p < 0.001). Conclusions: The rates of hospital admissions, incidence, and mortality related to IE diagnosis in PLWH in Spain decreased from 1997 to 2014, while other changes in clinical characteristics, mode of acquisition, and pathogens occurred over this time.

scholarly journals Healthcare-Associated Laboratory-Confirmed Bloodstream Infections—Species Diversity and Resistance Mechanisms, a Four-Year Retrospective Laboratory-Based Study in the South of Poland

2021 ◽  
Vol 18 (5) ◽  
pp. 2785
Author(s):  
Agnieszka Chmielarczyk ◽  
Monika Pomorska-Wesołowska ◽  
Dorota Romaniszyn ◽  
Jadwiga Wójkowska-Mach
Keyword(s):  
Bloodstream Infections ◽  
Diagnostic Techniques ◽  
Resistance Mechanisms ◽  
Infection Prevention And Control ◽  
The South ◽  
Coagulase Negative Staphylococci ◽  
Aminoglycoside Resistance ◽  
Gram Negative ◽  
Maldi Tof ◽  
Carbapenem Resistant

Introduction: Regardless of the country, advancements in medical care and infection prevention and control of bloodstream infections (BSIs) are an enormous burden of modern medicine. Objectives: The aim of our study was to describe the epidemiology and drug-resistance of laboratory-confirmed BSI (LC-BSIs) among adult patients of 16 hospitals in the south of Poland. Patients and methods: Data on 4218 LC-BSIs were collected between 2016–2019. The identification of the strains was performed using MALDI-TOF. Resistance mechanisms were investigated according to European Committee on Antimicrobial Susceptibility Testing, EUCAST recommendations. Results: Blood cultures were collected from 8899 patients, and LC-BSIs were confirmed in 47.4%. The prevalence of Gram-positive bacteria was 70.9%, Gram-negative 27.8% and yeast 1.4%. The most frequently isolated genus was Staphylococcus (50% of all LC-BSIs), with a domination of coagulase-negative staphylococci, while Escherichia coli (13.7%) was the most frequent Gram-negative bacterium. Over 4 years, 108 (2.6%) bacteria were isolated only once, including species from the human microbiota as well as environmental and zoonotic microorganisms. The highest methicillin resistant Staphylococcus aureus (MRSA) prevalence was in intensive care units (ICUs) (55.6%) but S. aureus with resistance to macrolides, lincosamides and streptogramins B (MLSB) in surgery was 66.7%. The highest prevalence of E. faecalis with a high-level aminoglycoside resistance (HLAR) mechanism was in ICUs, (84.6%), while E. faecium-HLAR in surgery was 83.3%. All cocci were fully glycopeptide-sensitive. Carbapenem-resistant Gram-negative bacilli were detected only in non-fermentative bacilli group, with prevalence 70% and more. Conclusions: The BSI microbiology in Polish hospitals was similar to those reported in other studies, but the prevalence of MRSA and enterococci-HLAR was higher than expected, as was the prevalence of carbapenem-resistant non-fermentative bacilli. Modern diagnostic techniques, such as MALDI-TOF, guarantee reliable diagnosis.

Inoculation of Citric Acid-Fermenting Bacteria into Raw Milk in Farm Bulk Tanks

1979 ◽  
Vol 42 (1) ◽  
pp. 51-54 ◽  
Author(s):  
C. H. WHITE ◽  
S. G. SHILOTRI
Keyword(s):  
Hydrogen Peroxide ◽  
Raw Milk ◽  
Federal Agencies ◽  
Health Departments ◽  
State Health ◽  
Toxic Agent ◽  
Streptococcus Lactis ◽  
Fermenting Bacteria ◽  
Viable Bacteria ◽  
Bulk Tank

Cultures of Streptococcus lactis subsp. diacetylactis and Leuconostoc cremoris were added together in the amount of 0.5% to raw milk in a farm bulk tank. This treatment did not significantly reduce the psychrotrophic or coliform population as hypothesized; however, the shelf-life was extended on products made from this raw milk by an average of 1 day. Also, the legal question of adding viable bacteria to the raw milk needs to be considered by state health departments and appropriate federal agencies. Since hydrogen peroxide is reported to be the toxic agent (to the psychrotrophs) released by the citrate fermenters, the obvious fact is noted that this agent can already be added to milk designed for cheese manufacture.

Keeping quality of milk in relation to the copper content and temperature of pasteurization

1986 ◽  
Vol 53 (3) ◽  
pp. 391-406 ◽  
Author(s):  
John E. Ford ◽  
Monika J. A. Schröder ◽  
Michael A. Bland ◽  
Kim S. Blease ◽  
K. John Scott
Keyword(s):  
Heat Treatment ◽  
Raw Milk ◽  
High Heat ◽  
Cu Content ◽  
Storage Losses ◽  
C Storage ◽  
B Complex Vitamins ◽  
Highly Correlated ◽  
Quality Of Milk ◽  
The Stability

SUMMARYFor milk from four herds of cows, maintained under different conditions of feeding and management, the natural Cu content and the stability of the ascorbate were highly correlated. Low Cu levels in milk from cows at pasture at farms A and B during the summer were associated with low storage losses of ascorbate. During this period, the milk of cows at farms C and D (on forage and Cu-supplemented concentrate) was richer in Cu, and losses of ascorbate were high. Heat treatment of the milk stabilized the ascorbate. Thus, in ‘high Cu’ milk (60 µg Cu/l), loss of ascorbate in the raw milk was 58% at 2 d, as against 17% after pasteurization at 72 °C and no loss after treatment at 82 °C. Storage of milk in light caused rapid destruction of ascorbate, equally with 72 and 82 °C heat treatments. The effects were examined of milk pasteurization temperature (72–82 °C) on flavour stability, bacteriological quality and vitamins of the B-complex. Heat treatment at 82 °C increased the susceptibility of vitamin B12 to destruction by light, but otherwise caused no greater losses of B-complex vitamins than did treatment at 72 °C. Taste panel ratings showed an initial preference for milk heated at 72 °C, but on storage of this milk in darkness the flavour score fell progressively and at 5 d it was judged ‘stale’. Treatment at 82 °C gave a faint ‘cooked’ flavour although, unlike that of the 72 °C-treated milk, the flavour remained stable throughout 14-d storage and after d 8 was increasingly preferred. On exposure to light after treatment at 72 °C milks rapidly acquired an unpleasant‘oxidized’ flavour, but after treatment at 82 °C, exposure to light had no such adverse effect on flavour during the early days of storage. Pasteurization at ∼ 80 °C offers a potential for improvement in the oxidative stability of milk and its contribution of vitamin C to the diet.

scholarly journals Effect of a 0.5% chlorhexidine gel on dental plaque superinfecting microorganisms in mentally handicapped patients

2003 ◽  
Vol 17 (3) ◽  
pp. 228-233 ◽  
Author(s):  
Cláudio Mendes Pannuti ◽  
Roberto Fraga Moreira Lotufo ◽  
Silvana Cai ◽  
Maria da Conceição Saraiva ◽  
Nívea Maria de Freitas ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Placebo Group ◽  
Dental Plaque ◽  
Test Group ◽  
Control Group ◽  
Mentally Handicapped ◽  
Bacterial Populations ◽  
Gram Negative ◽  
Supragingival Plaque ◽  
Chlorhexidine Gel

A randomized clinical trial was conducted to investigate the effect of a 0.5% chlorhexidine (CHX) gel on dental plaque superinfecting microorganisms in mentally handicapped patients. Thirty inmates from the institution "Casas André Luiz" were assigned to either test group (CHX gel, n = 15) or control group (placebo gel, n = 15). The gel was administered over a period of 8 weeks. Supragingival plaque samples were collected at baseline, after gel use (8 weeks) and 16 weeks after baseline. The presence of Gram-negative Enterobacteriaceae, Staphylococcus and yeasts was evaluated. No significant growth of any superinfecting microorganism was observed in the CHX group, when compared to the placebo group. The results indicated that the 0.5% chlorhexidine gel did not produce an undesirable shift in these bacterial populations.

scholarly journals Multidrug-resistant bacteria isolated from surgical site of dogs, surgeon's hands and operating room in a veterinary teaching hospital in Brazil

2021 ◽  
Author(s):  
Mareliza Possa de Menezes ◽  
Mariana Borzi ◽  
Mayara Ruaro ◽  
Marita Cardozo ◽  
Fernando Ávila ◽  
...  
Keyword(s):  
Multidrug Resistant ◽  
High Rate ◽  
Resistant Bacteria ◽  
Coagulase Negative Staphylococci ◽  
Gram Negative ◽  
Source Of Infection ◽  
The One ◽  
Clean Contaminated ◽  
In The Beginning ◽  
Coagulase Positive Staphylococci

Abstract The aim of this study was to evaluate the prevalence and antimicrobial resistance profile of Gram-positive cocci and Gram-negative bacilli isolated from the surgical environment. All samples were collected during the intraoperative period of clean/clean-contaminated (G1) and contaminated (G2) surgery. A total of 150 samples were collected from the surgical wound in the beginning (n = 30) and end (n = 30) of the procedure, surgeon’s hands before (n = 30) and after (n = 30) antisepsis and the surgical environment (n = 30). Forty-three isolates with morphological and biochemical characteristics of Staphylococcus spp. and 13 of Gram-negative bacilli were obtained. Coagulase-negative staphylococci (85.71% [18/21]), coagulase-positive staphylococci (9.52% [2/21]) and Pseudomonas spp. (47.52% [1/21]) in G1, and coagulase-negative staphylococci (40% [14/35]), coagulase-positive staphylococci (20% [7/35]), Proteus spp. (17.14% [6/35]), E. coli (8.57% [3/35]), Pseudomonas spp. (2.86% [1/35]) and Salmonella spp. (2.86 [1/35]) in G2 were more frequently isolated, and a high incidence of multidrug resistance was observed in coagulase-negative staphylococci (87.5% [28/32]), coagulase-positive staphylococci (100% [11/11]) and Gram-negative bacilli (76.92% [10/13]). Methicillin-resistant Staphylococcus spp. accounted for 83.72% (36/43) of the Staphylococcus strains. Gram-negative bacilli cefotaxime-resistance constituted 81.82% (9/11) and imipenem resistance constituted 53.85% (7/13). The high rate of resistance of commensal bacteria found in our study is worrying. Coagulase-negative staphylococci are community pathogens related to nosocomial infections in human and veterinary hospitals, their presence in healthy patients and in veterinary professionals represent an important source of infection in the one health context. Continuous surveillance and application of antimicrobial stewardship programs are essential in the fight against this threat.

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