Comparison of the effects of three fluorocarbons on certain bacteria

1975 ◽  
Vol 21 (2) ◽  
pp. 221-226 ◽  
Author(s):  
O. W. Van Auken ◽  
J. Healy ◽  
A. J. Kaufmann
Keyword(s):  
Serratia Marcescens ◽  
Bacterial Growth ◽  
Clostridium Botulinum ◽  
Inhibitory Effect ◽  
Similar Response ◽  
Gram Negative ◽  
Anaerobic Microorganisms ◽  
Respiration Rates ◽  
Test Organisms ◽  
Aerobic And Anaerobic

Three fluorocarbons were tested to determine their effect on bacterial growth. Freon 11 and 21 in various concentrations had an inhibitory effect on selected test organisms, but Freon 22 had no effect. Both aerobic and anaerobic microorganisms, as well as gram-positive and gram-negative species, were included among the bacteria tested. Freon 11 and 21 caused a similar response with Freon 11 being more inhibitory to some species and Freon 21 more inhibitory to others. Inhibition was dependent on the concentration of the halocarbon and resulted in decreased respiration rates at all concentrations tested. Results reported here indicate that the action of the fluorocarbons tested is bactericidal rather than bacteriostatic. Serratia marcescens and Clostridium botulinum were the species most sensitive to the halocarbons tested.

scholarly journals Optimization of Agitation Rate in Bioreactor Increases Chitinase Activity of Serratia marcescens PT6

2020 ◽  
Vol 147 ◽  
pp. 03019
Author(s):  
Amara Faiz Wriahusna ◽  
Niswah Umhudloh Dzakiyya ◽  
Indun Dewi Puspita ◽  
Sri Pudjiraharti
Keyword(s):  
Serratia Marcescens ◽  
Bacterial Growth ◽  
Agar Medium ◽  
Chitinase Activity ◽  
Colloidal Chitin ◽  
Gram Negative Bacteria ◽  
Agitation Rate ◽  
Anova Analysis ◽  
Gram Negative ◽  
Shrimp Pond

Serratia marcescens PT6 is a Gram-negative bacteria isolated from shrimp pond sediment that capable of producing chitinase. This study aimed to observe the effect of agitation rate on growth and chitinase activity of S. marcescens PT-6 in a bioreactor. The production of chitinase was done in 1.5 l bioreactor using colloidal chitin broth at the condition of pH 7, the temperature of 30°C, aeration of 0.04 vvm, and variation of agitation rate (200, 350, 500 rpm). Bacterial growth was measured by colonies counting in agar medium, while chitinase activity was measured by means of colorimetric every day for four days incubation. The results of ANOVA analysis show that the agitation rate had no effect on bacterial growth, but a significant effect (P<0.05) was observed on chitinase activity. The highest growth and chitinase activity were obtained at 200 rpm, with the highest chitinase activity of 0.006 ± 0.001 U/ml was at day-2. This study implies that the optimized agitation rate in the bioreactor increased the chitinase activity produced by S. marcescens PT-6.

scholarly journals Quorum sensing modulatory effect of sound stimulation on Serratia marcescens and Pseudomonas aeruginosa

2016 ◽  
Author(s):  
Vijay Kothari ◽  
Pooja Patel ◽  
Chinmayi Joshi ◽  
Brijesh Mishra ◽  
Shashikant Dubey ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Serratia Marcescens ◽  
Bacterial Growth ◽  
Gram Negative Bacteria ◽  
Sound Waves ◽  
Sound Stimulation ◽  
Gram Negative ◽  
Metabolite Production ◽  
Frequency Sound

AbstractEffect of nine different mono-frequency sound stimuli on two gram-negative bacteria (Pseudomonas aeruginosa and Serratia marcescens) was investigated. Frequency of the test sound ranged from 100 Hz to 2,000 Hz. Both the test bacteria responded differently to sonic stimulation. Sound corresponding to 600 HZ caused a notable reduction in quorum sensing (QS) regulated production of the pigment pyoverdine by P. aeruginosa. 400 Hz sound affected prodigiosin production by S. marcescens the most. 500 Hz sound could enhance prodigiosin production without affecting growth of the producing bacterium, suggesting the effect purely to be QS modulatory. This study has demonstrated the capacity of the sound waves of affecting bacterial growth and quorum sensing regulated metabolite production.

Microbiological Quality and the Inability of Proteolytic Clostridium botulinum To Produce Toxin in Film-Packaged Fresh-Cut Cabbage and Lettuce

1998 ◽  
Vol 61 (9) ◽  
pp. 1148-1153 ◽  
Author(s):  
Y.-Y. HAO ◽  
R. E. BRACKETT ◽  
L. R. BEUCHAT ◽  
M. P. DOYLE
Keyword(s):  
Clostridium Botulinum ◽  
Microbiological Quality ◽  
Microbial Populations ◽  
Mouse Bioassay ◽  
Psychrotrophic Bacteria ◽  
Anaerobic Microorganisms ◽  
Significant Difference ◽  
Yeasts And Molds ◽  
Aerobic And Anaerobic

The production of toxin by a 10-strain mixture of proteolytic Clostridium botulinum in fresh produce packaged in polyethylene films having high (7,000 cc/m2/24 h; HOTR) and low (3,000 cc/m2/24 h; LOTR) relative oxygen permeability was determined. Shredded cabbage and lettuce inoculated with ~102 spores/g were placed in bags composed of the two films (1.4 kg/bag), and the bags were then vacuum sealed. Produce was stored at 4, 13, and 21°C for up to 21 (cabbage) or 28 (lettuce) days and analyzed periodically. At each sampling time, the gas composition within the bags, pH of the produce, and microbial populations (total aerobic and anaerobic microorganisms, lactic acid bacteria, psychrotrophic bacteria, and yeasts and molds) were determined. In addition, the presence of botulinal toxin was determined using the standard U.S. Food and Drug Administration mouse bioassay protocol. Bags made of HOTR film prolonged sensory quality of cabbage and lettuce, especially at 13 and 4°C. Packaging material had an effect on the growth of various groups of microorganisms; however, there was not a general trend. For example, lettuce packaged in HOTR bags had higher aerobic microbial populations than that packed in LOTR, but no significant difference (P ≤ 0.05) was observed with cabbage. Growth of psychrotrophic bacteria was greater in vegetables packaged in HOTR film while growth of yeasts and molds was not affected by either packaging film. Most differences in microbial populations in produce packaged in LOTR and HOTR films were less than 1 log10 CFU/g. Botulinal toxin was not detected in cabbage or lettuce packaged in either film or stored under any test condition.

scholarly journals MICROBIOLOGICAL DIAGNOSTICS OF PYOINFLAMMATORY ABDOMINAL DISEASES

2016 ◽  
Vol 1 (4) ◽  
pp. 95-98
Author(s):  
Аюшинова ◽  
Natalya Ayushinova ◽  
Владимирова ◽  
Lyudmila Vladimirova ◽  
Ветохина ◽  
...  
Keyword(s):  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Anaerobic Microorganisms ◽  
Microbiological Diagnostics ◽  
Wall Specimen ◽  
Clinically Significant ◽  
Optimal Material ◽  
Aerobic And Anaerobic ◽  
Positive Results

The aim of the work was to establish the significance of complex bacteriological research in the diagnostics of acute appendicitis and to determine an optimal material for the research based on the findings. We examined 19patients with acute phlegmonous or acute gangrenous appendicitis (males, aged 18–60years). We performed bacteriological research of abdominal exudate (n=19) and biopsy specimen (n=19) of appendix wall taken before opening the lumen of the intestine. Both abdominal exudate and appendix wall specimen were taken at the same time. Aerobic and anaerobic microorganisms were detected and identified, antimicrobial susceptibility was tested. In total, we detected 25 strains of aerobic and 13 strains of anaerobic microorganisms. It has been established that a bioptate was most informative for testing (68.4 %); the parallel study of an abdominal exudate gave positive results in 21.1 % of cases. In the structure of clinically significant microflora dominated E.coli (43.3%), then went nonfermentative gram-negative bacteria (13.3%) and Bacteroidesspp. (16.7%). We marked growing resistance of detected strains of gram-negative bacteria to some antibiotics. For instance, 62 % of detected E.c oli strains were resistant to ampicillin, 25 % – to ciprofloxacin. 92 % of strains were resistant to cefepime, 93 % – to ceftriaxone, 77 % – to Amoxiclav, 67 % – to gentamicin, 90 % – to tobramycin. From one bioptate a strain of E. coli ESBL was separated. The study of intraoperative bioptate of appendix wall increases effectiveness of microbiological diagnostics in com-parison with the abdominal exudate research.

The effect of thyroxine and triiodothyronine on bacterial growth

1973 ◽  
Vol 19 (11) ◽  
pp. 1401-1405
Author(s):  
Nachman Garber ◽  
Batia Lupowitz-Donenfeld
Keyword(s):  
Bacterial Growth ◽  
Divalent Cations ◽  
Inhibitory Effect ◽  
Gram Negative Bacteria ◽  
Weak Effect ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Similar Inhibitory Effect ◽  
Free Iodine

The effects of L-thyroxine, D-thyroxine, and 3,5,3′-triiodothyronine on the growth of several Gram-positive and Gram-negative bacteria were examined. The first two compounds, at a concentration of 7.7 × 10−5 M, were found to have a considerable inhibitory effect while 3,5,3′-triiodothyronine had a very weak effect on the growth of the Gram-positive bacteria examined. The growth of the Gram-negative bacteria was not inhibited under the same conditions.Potassium iodide, at the same concentration, was not inhibitory. Release of free iodine from the thyroxine preparation was also excluded as contributing to the thyroxine effect because it was shown to be less toxic than thyroxine for Bacillus cereus 569 and to exhibit a similar inhibitory effect on Gram-positive and Gram-negative bacteria.The inhibition of Gram-positive bacteria by L-thyroxine was reduced by cations such as Mn2+, Fe2+, and Ca2+. However, the hormones were more potent in their effect compared to EDTA in the same molar concentration and the inhibition exerted by them was not so easily abolished by the divalent cations as it was in the case of EDTA. Although chelation could contribute to the inhibition of the bacteria by the iodinated hormones, it seems that it is not the only factor involved.

scholarly journals Regulation of Swarming Motility and flhDCSm Expression by RssAB Signaling in Serratia marcescens

2008 ◽  
Vol 190 (7) ◽  
pp. 2496-2504 ◽  
Author(s):  
Po-Chi Soo ◽  
Yu-Tze Horng ◽  
Jun-Rong Wei ◽  
Jwu-Ching Shu ◽  
Chia-Chen Lu ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
Binding Site ◽  
Promoter Region ◽  
Transcriptional Start Site ◽  
Direct Interaction ◽  
Underlying Mechanism ◽  
Inhibitory Effect ◽  
Start Codon ◽  
Mobility Shift

ABSTRACT Serratia marcescens cells swarm at 30°C but not at 37°C, and the underlying mechanism is not characterized. Our previous studies had shown that a temperature upshift from 30 to 37°C reduced the expression levels of flhDCSm and hagSm in S. marcescens CH-1. Mutation in rssA or rssB, cognate genes that comprise a two-component system, also resulted in precocious swarming phenotypes at 37°C. To further characterize the underlying mechanism, in the present study, we report that expression of flhDCSm and synthesis of flagella are significantly increased in the rssA mutant strain at 37°C. Primer extension analysis for determination of the transcriptional start site(s) of flhDCSm revealed two transcriptional start sites, P1 and P2, in S. marcescens CH-1. Characterization of the phosphorylated RssB (RssB∼P) binding site by an electrophoretic mobility shift assay showed direct interaction of RssB∼P, but not unphosphorylated RssB [RssB(D51E)], with the P2 promoter region. A DNase I footprinting assay using a capillary electrophoresis approach further determined that the RssB∼P binding site is located between base pair positions −341 and −364 from the translation start codon ATG in the flhDCSm promoter region. The binding site overlaps with the P2 “−35” promoter region. A modified chromatin immunoprecipitation assay was subsequently performed to confirm that RssB∼P binds to the flhDCSm promoter region in vivo. In conclusion, our results indicated that activated RssA-RssB signaling directly inhibits flhDCSm promoter activity at 37°C. This inhibitory effect was comparatively alleviated at 30°C. This finding might explain, at least in part, the phenomenon of inhibition of S. marcescens swarming at 37°C.

Characterization of Serratia species and qualitative detection of Serratia marcescens in raw and pasteurized milk by an analytical method based on polymerase chain reaction

2021 ◽  
Vol 67 (2) ◽  
pp. 3453-3464
Author(s):  
Evelin Korcz ◽  
László Varga ◽  
Zoltán Kerényi
Keyword(s):  
Serratia Marcescens ◽  
Bacterial Species ◽  
Relevant Literature ◽  
Inhibitory Effect ◽  
Test Methods ◽  
In Vitro Assays ◽  
Pasteurized Milk ◽  
Milk Samples ◽  
Microbiological Methods

Serratia species are opportunistic pathogenic microorganisms primarily known as nosocomial infectious agents, which can also cause food quality problems. The appearance of the extracellular pigment-producing Serratia marcescens in cow’s milk causes its red discoloration, posing a challenge to the dairy industry and food certification laboratories. The detection of the bacterium by conventional procedures based on microbiological methods is time-consuming and labor-intensive, and in many cases does not lead to satisfactory results due to the competitive inhibitory effect of the accompanying microflora. Following the analysis of the relevant literature, the published endpoint PCR methods and the primers used for the detection of S. marcescens were evaluated in in silico and in vitro assays, and then the procedure was tested on farm milk samples. Using the method, a total of 60 raw and pasteurized milk samples were analyzed, more than half of which (i.e., 32) were identified as S. marcescens positive. The significance of our work is mainly represented by the application of the published test methods in food industry practice. Our results highlight to the importance of detecting this bacterial species.

scholarly journals In Vitro and In Vivo Antibacterial Activities of a Novel Glycylcycline, the 9-t-Butylglycylamido Derivative of Minocycline (GAR-936)

1999 ◽  
Vol 43 (4) ◽  
pp. 738-744 ◽  
Author(s):  
P. J. Petersen ◽  
N. V. Jacobus ◽  
W. J. Weiss ◽  
P. E. Sum ◽  
R. T. Testa
Keyword(s):  
Anaerobic Bacteria ◽  
Tetracycline Resistance ◽  
Protective Effects ◽  
Gram Negative ◽  
E Coli ◽  
Resistance Determinants ◽  
Aerobic And Anaerobic ◽  
Ribosomal Protection

ABSTRACT The 9-t-butylglycylamido derivative of minocycline (TBG-MINO) is a recently synthesized member of a novel group of antibiotics, the glycylcyclines. This new derivative, like the first glycylcyclines, theN,N-dimethylglycylamido derivative of minocycline and 6-demethyl-6-deoxytetracycline, possesses activity against bacterial isolates containing the two major determinants responsible for tetracycline resistance: ribosomal protection and active efflux. The in vitro activities of TBG-MINO and the comparative agents were evaluated against strains with characterized tetracycline resistance as well as a spectrum of recent clinical aerobic and anaerobic gram-positive and gram-negative bacteria. TBG-MINO, with an MIC range of 0.25 to 0.5 μg/ml, showed good activity against strains expressing tet(M) (ribosomal protection), tet(A), tet(B),tet(C), tet(D), and tet(K) (efflux resistance determinants). TBG-MINO exhibited similar activity against methicillin-resistant Staphylococcus aureus (MRSA), penicillin-resistant streptococci, and vancomycin-resistant enterococci (MICs at which 90% of strains are inhibited, ≤0.5 μg/ml). TBG-MINO exhibited activity against a wide diversity of gram-negative aerobic and anaerobic bacteria, most of which were less susceptible to tetracycline and minocycline. The in vivo protective effects of TBG-MINO were examined against acute lethal infections in mice caused by Escherichia coli, S. aureus, andStreptococcus pneumoniae isolates. TBG-MINO, administered intravenously, demonstrated efficacy against infections caused byS. aureus including MRSA strains and strains containingtet(K) or tet(M) resistance determinants (median effective doses [ED50s], 0.79 to 2.3 mg/kg of body weight). TBG-MINO demonstrated efficacy against infections caused by tetracycline-sensitive E. coli strains as well asE. coli strains containing either tet(M) or the efflux determinant tet(A), tet(B), ortet(C) (ED50s, 1.5 to 3.5 mg/kg). Overall, TBG-MINO shows antibacterial activity against a wide spectrum of gram-positive and gram-negative aerobic and anaerobic bacteria including strains resistant to other chemotherapeutic agents. The in vivo protective effects, especially against infections caused by resistant bacteria, corresponded with the in vitro activity of TBG-MINO.

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