Bacteriology of the oral cavity of BALB/c mice

1986 ◽  
Vol 32 (8) ◽  
pp. 673-678 ◽  
Author(s):  
L. Trudel ◽  
L. St-Amand ◽  
M. Bareil ◽  
P. Cardinal ◽  
M. C. Lavoie
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Oral Cavity ◽  
Bacterial Flora ◽  
The Other ◽  
Limited Data ◽  
Oral Flora ◽  
Predominant Species ◽  
Oral Microflora ◽  
Lactobacillus Murinus

To be used as a model in dental research, an animal must fulfil experimental needs and information on the composition and variation of its oral flora must be available. Only limited data are available on the indigenous oral bacterial flora of BALB/c mice. In this work, a total of 671 isolates from different sites (saliva, tongue, teeth, and mucosa) of the oral cavity of BALB/c mice were identified. Only 18 different species were isolated, which indicates the relative simplicity of the flora. The predominant species of the total cultivable flora were "Lactobacillus muritius" (38%), Staphylococcus aureus (37%), Streptococcus faecalis (8%), Staphylococcus sciuri (4%), and Escherichia coli (3%). The other species each represent less than 2% of the flora. "Lactobacillus murinus" is found in greater proportion on mucosa than in the other sites, Staph. aureus predominates in saliva, and Strep. faecalis was found in greater proportion in tooth samples. Statistical analyses, using the minimum percentage of similarity, indicate that there is some variation among the microflora of different mice but that this difference is smaller for mice from the same lot. These results set the basis for the study of the variations of the indigenous oral microflora of BALB/c mice under different conditions.

scholarly journals In Vitro Activity of Newer and Conventional Antimicrobial Agents, Including Fosfomycin and Colistin, against Selected Gram-Negative Bacilli in Kuwait

Pathogens ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 75 ◽  
Author(s):  
Wadha Alfouzan ◽  
Rita Dhar ◽  
David Nicolau
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Agents ◽  
The Other ◽  
In Vitro Activity ◽  
Limited Data ◽  
Gram Negative ◽  
E Coli ◽  
Microbroth Dilution

Limited data are available on susceptibilities of these organisms to some of the recently made accessible antimicrobial agents. The in vitro activities of newer antibiotics, such as, ceftolozane/tazobactam (C/T) and ceftazidime/avibactam (CZA) along with some “older” antibiotics, for example fosfomycin (FOS) and colistin (CL) were determined against selected strains (resistant to ≥ 3 antimicrobial agents) of Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Minimum inhibitory concentrations (MIC) were determined by Clinical and Laboratory Standards Institute microbroth dilution. 133 isolates: 46 E. coli, 39 K. pneumoniae, and 48 P. aeruginosa were tested. Results showed that E. coli isolates with MIC50/90, 0.5/1 μ g / mL for CL; 4/32 μ g / mL for FOS; 0.25/32 μ g / mL for C/T; 0.25/8 μ g / mL for CZA, exhibited susceptibility rates of 95.7%, 97.8%, 76.1%, and 89.1%, respectively. On the other hand, K. pneumoniae strains with MIC50/90, 0.5/1 μ g / mL for CL; 256/512 μ g / mL for FOS; 2/128 μ g / mL for C/T; 0.5/128 μ g / mL for CZA showed susceptibility rates of 92.3%, 7.7%, 51.3%, and 64.1%, respectively. P. aeruginosa isolates with MIC50/90, 1/1 μ g / mL for CL; 128/128 μ g / mL for C/T; 32/64 μ g / mL for CZA presented susceptibility rates of 97.9%, 33.3%, and 39.6%, respectively. Higher MICs were demonstrated against most of the antibiotics. However, CL retained efficacy at low MICs against most of the isolates tested.

scholarly journals Evolution of the C30 Carotenoid Synthase CrtM for Function in a C40 Pathway

2002 ◽  
Vol 184 (23) ◽  
pp. 6690-6699 ◽  
Author(s):  
Daisuke Umeno ◽  
Alexander V. Tobias ◽  
Frances H. Arnold
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Substrate Specificity ◽  
Significant Variation ◽  
The Other ◽  
Biosynthetic Pathways ◽  
Product Range

ABSTRACT The C30 carotene synthase CrtM from Staphylococcus aureus and the C40 carotene synthase CrtB from Erwinia uredovora were swapped into their respective foreign C40 and C30 biosynthetic pathways (heterologously expressed in Escherichia coli) and evaluated for function. Each displayed negligible ability to synthesize the natural carotenoid product of the other. After one round of mutagenesis and screening, we isolated 116 variants of CrtM able to synthesize C40 carotenoids. In contrast, we failed to find a single variant of CrtB with detectable C30 activity. Subsequent analysis revealed that the best CrtM mutants performed comparably to CrtB in an in vivo C40 pathway. These mutants showed significant variation in performance in their original C30 pathway, indicating the emergence of enzymes with broadened substrate specificity as well as those with shifted specificity. We discovered that Phe 26 alone determines the specificity of CrtM. The plasticity of CrtM with respect to its substrate and product range highlights the potential for creating further new carotenoid backbone structures.

Growth and Death of Selected Microorganisms in Ultrafiltered Milk

1986 ◽  
Vol 49 (3) ◽  
pp. 233-235 ◽  
Author(s):  
PATRICIA HAGGERTY ◽  
NORMAN N. POTTER
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Skim Milk ◽  
Laboratory Scale ◽  
The Other ◽  
Streptococcus Faecalis ◽  
E Coli ◽  
Milk Samples ◽  
D Values ◽  
D Value

Studies were made to compare the growth and death of Staphylococcus aureus, Streptococcus faecalis and Escherichia coli in skim milk concentrated by ultrafiltration to that in unconcentrated skim milk. Skim milk was volume concentrated to 2× in laboratory-scale stirred UF cells. Behavior of the organisms was analyzed in four inoculated milk samples: 2× retentate, 1× water-diluted retentate, milk equivalent (retentate plus permeate) and unconcentrated skim milk. Growth of each organism and of total aerobes did not vary in the four milk samples at either 7 or 13°C. For S. faecalis and E. coli, D-values for samples heated to 62.7°C did not significantly differ in the four milk samples (p>0.01). The D-value of S. aureus in water-diluted retentate was slightly but significantly lower than those in the other three milk samples (p<0.01), possibly due to the lowered lactose level in this sample.

scholarly journals Bacterial phagocytosis by macrophages from lipopolysaccharide responder and nonresponder mouse strains

1980 ◽  
Vol 28 (3) ◽  
pp. 762-765
Author(s):  
A Cuffini ◽  
N A Carlone ◽  
G Forni
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
The Other ◽  
Mouse Strains ◽  
Bacterial Strains ◽  
Phagocytic Capacity ◽  
Tumoricidal Activity ◽  
E Coli ◽  
Proteose Peptone ◽  
Lipopolysaccharide Endotoxin

The phagocytic capacity of macrophages from C3H/H3J mice was assessed against lipopolysaccharide-producing (Escherichia coli) and -nonproducing (Staphylococcus aureus) bacteria. Despite their gene-coded unresponsiveness to lipopolysaccharide endotoxin and lymphokines and their defective tumoricidal activity, proteose peptone-induced C3H/HeJ macrophages did not display a defective phagocytic capacity, but rather displayed an enhanced phagocytosis of both bacterial strains compared with macrophages from closely related C3H/HeN mice. Unstimulated peritoneal resident C3H/HeJ macrophages, on the other hand, displayed a normal phagocytic activity toward E. coli and enhanced phagocytosis toward S. aureus.

scholarly journals COMPARISON OF ANTIBACTERIAL ACTIVITY OF HONEY AGAINST AEROBIC AND ANAEROBIC BACTERIA

2021 ◽  
pp. 41-43
Author(s):  
S. DHANARAJ ◽  
S. S. M. UMAMAGESWARI ◽  
M. MALAVIKA ◽  
G. BHUVANESHWARI
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Clostridium Perfringens ◽  
Anaerobic Bacteria ◽  
The Other ◽  
E Coli ◽  
Diffusion Technique ◽  
Aerobic And Anaerobic

Objective: To compare the antibacterial activity of honey against aerobic and anaerobic bacteria. Methods: Honey is extracted from the honey comb by trained persons. Antimicrobial activity of honey is performed by Agar Cup Diffusion technique for 3 bacteria Staphylococcus aureus, E. coli and Clostridium perfringens. Results: By performing the technique with proper guidance, it is observed that the Staphylococcus aureus specimen shows sensitivity to honey whereas the other two specimens Escherichia coli and clostridium perfringens doesn’t show any sensitivity to honey. Conclusion: Due to its vast antibacterial activity of honey, it can be used along with other antibiotics to increase its efficiency.

scholarly journals COMPARISON OF ANTIBACTERIAL ACTIVITY OF GARLIC AGAINST AEROBIC AND ANAEROBIC BACTERIA

2021 ◽  
pp. 44-46
Author(s):  
K. G. DHANUSH ◽  
S. S. M. UMAMAGESWARI ◽  
M. MALAVIKA ◽  
G. BHUVANESHWARI
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Clostridium Perfringens ◽  
Anaerobic Bacteria ◽  
The Other ◽  
E Coli ◽  
Diffusion Technique ◽  
Aerobic And Anaerobic

Objective: To compare the antibacterial activity of garlic against aerobic and anaerobic bacteria. Methods: Antimicrobial activity of garlic is performed by Agar cup diffusion technique for 3 bacteria Staphylococcus aureus, E. coli and clostridium perfringens. Results: By performing the technique with proper guidance, it is observed that the Staphylococcus aureus specimen shows sensitivity to garlic whereas the other two specimens Escherichia coli and clostridium perfringens doesn’t show any sensitivity to garlic. Conclusion: Due to its vast antibacterial activity of garlic, it can be used along with other antibiotics to increase its efficiency.

scholarly journals ANALYSIS OF PNEUMONIAASSOCIATED MORTALITY OF MONKEYS IN CAPTIVITY AND THE ROLE OF METHICILLIN-SENSITIVE STAPHYLOCOCCUS AUREUS (MRSA) IN THE RECOVERED MICROFLORA SPECTRUM

2018 ◽  
pp. 58-62
Author(s):  
V. A. Kalashnikova ◽  
A. V. Demerchyan
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacterial Flora ◽  
Autopsy Material ◽  
Tissue Samples ◽  
E Coli ◽  
Monkey Species ◽  
In Captivity ◽  
Polymicrobial Communities

Pneumonia-associated mortality of different monkey species in captivity in 2017 has been analyzed. The animal death frequency and seasonality was demonstrated. Pneumonia-associated mortality in baby monkeys and old monkeys exceeds the mortality of infants and mature animals. The maximum pneumonia-mortality rate in monkeys was observed in February, April and May. The spectrum of microorganisms recovered from lungs of dead animals was identified. The prevailing bacterial flora detected in case of pneumonia was Staphylococcus aureus (43.1%) and Escherichia coli (34.9%), which were detected both in monoculture and communities. One of the peculiarities of pneumonia in monkeys is high occurrence of polymicrobial communities. Most frequently S. aureus is observed in combinations with E. coli (52.5%). All recovered S. aureus cultures were methicillin-sensitive and did not have gene mecA in their genome. During performance of bacteriological tests of autopsy material the lung tissue samples can get contaminated with the foreign flora that’s why it’s quite difficult to speak about the role of these and those microorganisms as major disease agents.

Efficiency of Sodium Hypochlorite, Fumaric Acid, and Mild Heat in Killing Native Microflora and Escherichia coli O157:H7, Salmonella Typhimurium DT104, and Staphylococcus aureus Attached to Fresh-Cut Lettuce

2006 ◽  
Vol 69 (2) ◽  
pp. 323-329 ◽  
Author(s):  
NOZOMI KONDO ◽  
MASATSUNE MURATA ◽  
KENJI ISSHIKI
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Salmonella Typhimurium ◽  
Sodium Hypochlorite ◽  
Fumaric Acid ◽  
Bacterial Flora ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Mild Heat ◽  
Log Reduction

The effect of the disinfectant sodium hypochlorite (NaClO), with or without mild heat (50°C) and fumaric acid, on native bacteria and the foodborne pathogens Staphylococcus aureus, Escherichia coli O157:H7, and Salmonella Typhimurium DT104 attached to iceberg lettuce leaves was examined. The retail lettuce examined consistently harbored 6 to 7 log CFU/g of native bacteria throughout the study period. Inner leaves supported 1 to 2 log CFU/g fewer bacteria than outer leaves. About 70% of the native bacterial flora was removed by washing five times with 0.85% NaCl. S. aureus, E. coli, and Salmonella allowed to attach to lettuce leaves for 5 min were more easily removed by washing than when allowed to attach for 1 h or 2 days, with more S. aureus being removed than E. coli or Salmonella Typhimurium. An increase of time for attachment of pathogens from 5 min to 2 days leads to decreased efficiency of the washing and sanitizing treatment. Treatment with fumaric acid (50 mM for 10 min at room temperature) was the most effective, although it caused browning of the lettuce, with up to a 2-log reduction observed. The combination of 200 ppm of sodium hypochlorite and mild heat treatment at 50°C for 1 min reduced the pathogen populations by 94 to 98% (1.2- to 1.7-log reduction) without increasing browning.

scholarly journals EFFECTIVENESS OF HAND HYGIENE IN REDUCING BACTERIAL FLORA IN HEALTH CARE WORKERS-A STUDY OF IMPACT

2020 ◽  
pp. 1-3
Author(s):  
Prashant Singh ◽  
Pratibha Mane ◽  
Jyoti Sangwan
Keyword(s):  
Escherichia Coli ◽  
Health Care ◽  
Staphylococcus Aureus ◽  
Hand Hygiene ◽  
Health Care Workers ◽  
Bacterial Flora ◽  
Bacterial Load ◽  
Bacterial Colony ◽  
Care Workers ◽  
Two Samples

Introduction: Hand hygiene is simplest, most effective and least expensive tool to prevent health care worker associated infection. The compliance among HCW is low due to various reasons leading to increased morbidity and mortality in Healthcare associated infection (HAI). Proper hand hygiene significantly reduces bacterial flora and HAI. The study was planned with the aim to know the pattern of microbial flora and its drug resistance and effectiveness of hand hygiene in reducing bacterial load on hands of health care workers. Material and Methods: Both hand finger imprints of 50 participants were taken on Blood agar before and after hand hygiene. The plates were incubated 24-48 hours at 37°C.Colony count was done. Bacteria were identified by their colony characteristics and biochemical reactions. AST was performed as per CLSI 2019 guidelines. Results: 90-99% reduction in bacterial colony count after hand hygiene was seen in majority of participants Mixed growth was seen in ten samples. Micrococcus was most common organism isolated in twenty-four samples, followed by diptheroids in sixteen samples, Coagulase negative staphylococcus (CoNS) in fourteen samples and Staphylococcus aureus in six samples .Three CoNS and four Staphylococcus aureus were Methicillin resistant. Gram negative bacilli isolated were Klebsiella species, Pseudomonas species and Escherichia Coli each in two samples respectively One Escherichia Coli was ESBL producer. All the GNB were sensitive to carbapenem. After performing hand hygiene micrococcus was isolated from four sample, diptheroids from three and CONS from one sample. Staphylococcus aureus and GNB were not found after hand hygiene Conclusion: HCW hands are colonized with bacteria. Proper hand hygiene technique awareness and its compliance significantly reduce bacterial load and decrease HAI.

scholarly journals Distinct stress responses to pyocyanin by planktonic and sessile Staphylococcus aureus UFPEDA 02 and Escherichia coli UFPEDA 224 / Respostas distintas ao estresse causado pela piocianina em células planctônicas e sésseis de Staphylococcus aureus UFPEDA 02 e Escherichia coli UFPEDA 224

2021 ◽  
Vol 7 (10) ◽  
pp. 98074-98088
Author(s):  
Bianca Teixeira Morais De Oliveira ◽  
Kaíque Yago Gervazio De Lima ◽  
Ray Ravilly Alves Arruda ◽  
Ulrich Vasconcelos
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Stress Responses ◽  
Cell Concentration ◽  
The Other ◽  
Planktonic Cells ◽  
E Coli ◽  
Highly Sensitive ◽  
A Cell

Antimicrobial activity of pyocyanin against competing organisms of Pseudomonas aeruginosa is related to the oxidative stress that the compound promotes in susceptible cells. The objective of this work was to produce, extract and verify the activity of pyocyanin in planktonic and sessile forms from clinical strains, Staphylococcus aureus UFPEDA 02 and Escherichia coli UFPEDA 224. About 600 µg/mL of pyocyanin were obtained. The planktonic cells were highly sensitive. The MIC determined for S. aureus UFPEDA 02 and E. coli UFPEDA 224 were 18.75 and 37.5 µg/mL, respectively. The pyocyanin demonstrated biocidal effect against S. aureus UFPEDA 02. On the other hand, pyocyanin was not active in either sessile strain. The presence of the pigment allowed a greater adherence of the strains, forming more robust biofilms compared to the control. S. aureus UFPEDA 02 and E. coli UFPEDA 224 presented moderate and high hydrophobicity, respectively. Glass and dolomite surfaces were tested in the in vitro biofilm test. Both strains formed the biofilm better on the dolomite surface, obtaining a cell concentration (MPN/cm2) in the order of 3 log units after 48h of incubation.

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