scholarly journals Detection of bacterial samples on the aquatic ecosystems adjacent to Saquarema Lagoon – Rio de Janeiro

2016 ◽  
Vol 14 (2) ◽  
pp. 147
Author(s):  
Barbara Araujo Nogueira ◽  
Julianna Giordano Botelho Olivella ◽  
Adriana Costa Gil ◽  
Frederico Meirelles-Pereira ◽  
Verônica Dias Gonçalves ◽  
...  

Introduction: Saquarema Lagoon (RJ) has a high ecological and economic value owing to its multiple uses. The population’s constant growth increases the amount of sewage containing bacteria and antimicrobial drugs that are discharged to the environment. Objectives: to detect Gram negative bacilli able to colonize or infect humans and animals and determine their antimicrobial resistance profiles. Methodology:samples were collected in the city centre in April 2010 and at Jaconé (Lagoon’s most preserved site) in February 2011. The total and thermo tolerant coliforms were determined and the isolation of samples was made using agar media containing  32cg/ mL of cephalotin. All samples were tested for antimicrobial susceptibility (AST) and on 16 samples, plasmid DNA was extracted. Results: different Gram negative bacteria were detected, such as: Enterobacter spp, Citrobacter freundii, Klebsiella pneumoniae and Pseudomonas aeruginosa. The coliform results showed that the water quality is proper for Human recreation. AST results demonstrated the existence of bacteria resistant to antimicrobial drugs frequently used in the community. It was possible to detected high molecular weight plasmids and nine samples (56,25%) showed at least one plasmid DNA electrophoresis band. Conclusions: there were not detected resistant samples to antimicrobial drugs normally used in hospital settings, which may possibly refute the idea of a contamination by nosocomial and/or veterinary sewage discharge.

2019 ◽  
Vol 10 (3) ◽  
pp. 91-96 ◽  
Author(s):  
O. Yu. Kutsevalova ◽  
I. O. Pokudina ◽  
D. A. Rozenko ◽  
D. V. Martynov ◽  
M. Yu. Kaminsky

Objectives: to analyze the prevalence of strains of gram-negative bacteria - pathogens of infectious complications resistant to carbapenems, including through the production of carbapenemases isolated from various clinical biomaterials in hospitalized patients of hospitals in the city of Rostov-on-Don.Materials and methods: 366 gram-negative bacterial isolates were studied, from patients from 16 wards, 9 treatment-and-prophylactic institutions of the city of Rostov-on-Don and the region. The study was conducted by traditional microbiological method. Species identification of strains and sensitivity to antimicrobial drugs were determined on a Vitek 2 automatic analyzer (BioMerieux, France). The strains insensitive to carbapenems were tested for the presence of carbapenemases using CIM-test. MBL was detected by the effect of suppression of their activity in the presence of EDTA. MBL genes were detected by PCR-RV test kit “AmpliSens MDR MBL-FL”, “AmpliSens MDR KPC/OXA-48-FL”. The conclusion about the production of BLRS was made by the presence of synergism of cephalosporins of III-IV generation with clavulanic acid by the method of double discs.Results: of the 366 isolates tested, gram-negative bacteria accounted for 74.2 %: Klebsiella pneumoniae — 33.0 %, Escherichia coli — 19.0 %, Acinetobacter baumannii — 18.0 %, Pseudomonas aeruginosa — 15.0 %. Resistance to carbapenems was detected in 90.9 % of A.baumannii strains, more than 50 % of P.aeruginosa and K.pneumoniae. LBR production was detected in more than 90 % of K.pneumoniae and about 80 % of E. coli. In A. baumannii and K.pneumoniae isolates, the presence of OXA and NDM genes was found, and in P.aeruginosa, VIM groups.Conclusion: enterobacteria resistant to beta-lactams, producing extended-spectrum beta-lactamases and carbapenemases are one of the leading causative agents of infectious complications in hospitals of Rostov-on-don and the region, almost not inferior in frequency of occurrence of bacteria of the genus Acinetobacter spp. and Paeruginosa. This determines the importance of detection of resistance mechanisms not only for the purpose of optimal etiotropic therapy, but also for epidemiological control of the spread of resistant strains and the development of infection control measures.


2000 ◽  
Vol 44 (4) ◽  
pp. 848-852 ◽  
Author(s):  
C. M. Kunin ◽  
W. Y. Ellis

ABSTRACT Mefloquine was found to have bactericidal activity against methicillin- and fluoroquinolone-susceptible and -resistant strains ofStaphylococcus aureus and Staphylococcus epidermidis and gentamicin- and vancomycin-resistant strains ofEnterococcus faecalis and Enterococcus faecium. The MICs were 16 μg/ml, and the minimal bactericidal concentrations (MBCs) were 16 to 32 μg/ml. These concentrations cannot be achieved in serum. Mefloquine was active at a more achievable concentration against penicillin-susceptible and -resistant Streptococcus pneumoniae, with MICs of 0.2 to 1.5 μg/ml. Mefloquine was not active against gram-negative bacteria and yeasts. In an attempt to find more active derivatives, 400 mefloquine-related compounds were selected from the chemical inventory of The Walter Reed Army Institute of Research. We identified a series of compounds containing a piperidine methanol group attached to pyridine, quinoline, and benzylquinoline ring systems. These had activities similar to that of mefloquine against S. pneumoniae but were far more active against other gram-positive bacteria (MICs for staphylococci, 0.8 to 6.3 μg/ml). They had activities similar to that of amphotericin B againstCandida spp. and Cryptococcus neoformans. Combinations of the compounds with gentamicin and vancomycin were additive against staphylococci and pneumococci. The MIC and MBC of gentamicin were decreased by four- to eightfold when this drug was combined with limiting dilutions of the compounds. There was no antagonism with other antimicrobial drugs. The compounds were rapidly bactericidal. They appear to act by disrupting cell membranes. Combinations of the compounds with aminoglycoside antibiotics may have potential for therapeutic use.


2019 ◽  
Vol 32 (12) ◽  
pp. 1577-1580
Author(s):  
Frederico Schmitt Kremer ◽  
Amanda Munari Guimarães ◽  
Christian Domingues Sanchez ◽  
Luciano da Silva Pinto

The Xanthomonas genus, comprises more than 30 species of gram-negative bacteria, most of which are pathogens of plants with high economic value, such as rice, common bean, and maize. Transcription activator-like effectors (TALEs), which act by regulating the host gene expression, are some of the major virulence factors of these bacteria. We present a novel tool to identify TALE genes in the genome of Xanthomonas strains and their respective targets. The analysis of the results obtained by TargeTALE in a proof-of-concept validation demonstrate that, at optimum setting, approximately 93% of the predicted target genes with available expression data were confirmed as upregulated during the infection, indicating that the tool might be useful for researchers in the field.


2004 ◽  
Vol 67 (5) ◽  
pp. 999-1004 ◽  
Author(s):  
DIKE O. UKUKU ◽  
WILLIAM F. FETT

Standardized methods for applying sanitizer treatments to cantaloupes and for recovering surviving native microflora or Salmonella on inoculated cantaloupe after sanitizing are lacking. Accordingly, the objectives of this study were to compare four methods for applying sanitizers (dipping, dipping with rotation, dipping with agitation, and dipping with rubbing) using 200 ppm of chlorine or 5% H2O2, two recovery methods (homogenization of rind plugs in a stomacher or blender), and five selective recovery media for Salmonella. Whole cantaloupes were submerged in a cocktail of five strains of Salmonella (each at approximately 2 × 108 CFU/ml) for 10 min and allowed to dry for 1 h inside a biosafety cabinet and stored at 20° C for approximately 23 h before sanitizing. The recovery of Salmonella from whole cantaloupe without sanitizing averaged 5.09 log CFU/cm2 by blending and 4.30 log CFU/cm2 by homogenization in a stomacher for the five selective agar media. Microbial populations ( Salmonella or the indigenous aerobic mesophilic bacteria, gram-negative bacteria, lactic acid bacteria, Pseudomonas spp., and yeast and mold) were not significantly (P > 0.05) reduced by treating with water regardless of the treatment method used. Sanitizing with chlorine or H2O2 by dipping, with or without rotation for 2 min, also did not reduce microbial populations. However, populations of all classes of native microflora and Salmonella were significantly (P < 0.05) reduced by sanitizer treatments (2 min) applied with agitation or by rubbing. In general, sanitizer treatments applied by rubbing resulted in greater log reductions (by up to 1.7 log unit) than for treatments applied with agitation. Populations of native microflora and Salmonella recovered from cantaloupe were higher (by up to 1.8 log unit) by blending compared to homogenization in a stomacher. In most instances, selective media used did not differ significantly (P > 0.05) for recovery of Salmonella after washing treatments.


2019 ◽  
Vol 4 (4) ◽  
pp. 240-243
Author(s):  
P.M. Akbari ◽  
V.R. Shah

A series of new substituted cyclohexenone derivatives have been synthesized by the reaction of various substituted chalcones with ethylacetoacetate. Some new N-(4-(3-aryl-acryloyl)phenyl)cyclopropane carboxamide were prepared by Claisen-Schmidt condensation method in presence of sodium hydroxide in ethanol solvent under stirring. The synthesized compounds were characterized by their spectral (IR, NMR, Mass) data and screened for their antimicrobial activities against Gram-positive and Gram-negative bacteria by using standard antimicrobial drugs.


2018 ◽  
Vol 4 (2) ◽  
pp. 63-68
Author(s):  
Daniel Lantang ◽  
Desi Paiman

The research on identification of aerobic bacteria causing nosocomial infection in the surgery room of General Hospital (RSU) Abepura, Jayapura had been done from August–December 2008. Samples were taken from room air (30 minutes) using blood agar media and from certain tools at some points using brain heart infusion media (BHI). The colony appearance was observed after 24 hours of incubation period of bacterial growth. Further analysis to identify the aerobic bacteria causing nosocomial infections was done by several tests in Jayapura Health Laboratory. The result showed that there were 15 aerobic bacteria consisted of: the coccid gram–positive bacteria: Staphylococus epidermidis, S. aureus, S. saprophyticus, Streptcoccus sp; the rod gram-positive bacteria: Listeria monocytogenes, Diptheroid sp, Lactobacillus sp and gram-negative bacteria: Providence rettgeri, Pseudomonas puttrefaciens, Klebsiela ozaena, P. malthophyla, Morganela morganii, Serattia sp, K. oxytoca, and K. pneumonia. Key words: Aerobic bacteria, identification of bacteria, nosocomial infection, surgical room, Jayapura.


2018 ◽  
Vol 22 (2) ◽  
pp. 267-271
Author(s):  
V.G. Paliy ◽  
I.G. Paliy ◽  
A.O. Dudar ◽  
D.V. Paliy ◽  
A. V. Kulyk

Successful research by scientists of new synthetic substances of various chemical groups contributes to the broadening of the arsenal of antimicrobial drugs for the prevention and treatment of purulent-inflammatory diseases. Antimicrobial drugs, as a rule, suppress pathogenic, invasive, adhesive properties and reduce the resistance of microorganisms to antibiotics in pathogens of supportive inflammatory diseases; significantly increase the effectiveness of treatment of diseases of infectious origin. The purpose of the study was to study the physicochemical, antimicrobial properties of derivatives of menthol, phenol and quinoline. The results of the study of physicochemical, antimicrobial properties of six chemical compounds of menthol, quinoline, and phenol derivatives using the principle of complex research, in which physicochemical, microbiological methods were used, are presented. There was shown that quaternary ammonium compounds of the menthol derivatives were alike white powders with a molecular weight of 581–693, a melting point of 990 to 1850° C. The chemicals are soluble in water, ethanol. Quinoline preparations have a molecular weight of 687; 756, melting point 178–2000°C; dissolved in ethanol. Compounds of phenol had a molecular weight of 111, 112, a melting point of 1020, 1100°C was soluble in ethanol. It has been established that synthesized substances possess a wide spectrum of antimicrobial action on Gram-positive, Gram-negative bacteria, Candida albicans. In antibiotic resistant strains of Staphylococci no markers of resistance to drugs containing in the molecule menthol, phenol, quinoline were found. In complex physical and chemical systems, it was important to study the coefficient of surface tension of solutions of drugs, which was an important objective physical indicator of the molecular state of various drugs. Distilled water was used as a control. Experiments were performed according to a well-known technique. According to the results of the study, in the control the surface tension of water was it was found to be 55,70 dn/cm2. In an experiment with 0,1% solution of decamethoxin; the drug number 2 was 40,80 dn/cm2 and 38,20 dn/cm2. In derivatives of quinoline (DN, drug № 4), was 39,60 dn/cm2 and 34,50 dn/cm2. Solutions of phenol (preparations №5; №6) were characterized by surface tension 32,40–43,50 dn/cm2. Surface tension of solutions of preparations depended on their chemical structure. The antimicrobial properties of the preparations were determined on the museum and clinical strains of microorganisms, which had typical tynctorial, morphological, and cultural characteristics. For a complete biological characterization in strains of Staphylococci, the formation of coagulase enzymes, lecithovitellase, hemolysins, and mannitol fermentation in anaerobic conditions were studied. At 12 museum and clinical strains of bacteria, bacteriostatic and bactericidal effects of six drugs, which are derivatives of menthol (DK, №2), quinoline (DN, №4), phenol (preparations №5, №6), have been detected. Derivatives of menthol acted bactericidal to Staphylococci at doses of 0,48-3,9 μg/ml; Quinoline derivatives in the range of 7,8–15,6 μg/ml; derivatives of phenol 31,25–62,5 μg/ml, respectively. Staphylococci were highly resistant to phenol derivatives (31,25–62,5 μg/ml). Gram-negative bacteria exhibited high resistance to quinoline and phenol derivatives (250–500 μg/ml). Summing up the results of determining the antimicrobial action of antiseptics derivatives of menthol, quinoline, it should be emphasized that the drugs have high activity in relation to Staphylococci (0,24–7,8 μg/ml). Phenol derivatives have low bacteriostatic and bactericidal effects on Gram-negative bacteria (125–500 μg/ml), which limits their use in medicine.


2017 ◽  
Vol 61 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Mohsen Arzanlou ◽  
Wern Chern Chai ◽  
Henrietta Venter

Gram-negative bacteria are responsible for a large proportion of antimicrobial-resistant infections in humans and animals. Among this class of bacteria are also some of the most successful environmental organisms. Part of this success is their adaptability to a variety of different niches, their intrinsic resistance to antimicrobial drugs and their ability to rapidly acquire resistance mechanisms. These mechanisms of resistance are not exclusive and the interplay of several mechanisms causes high levels of resistance. In this review, we explore the molecular mechanisms underlying resistance in Gram-negative organisms and how these different mechanisms enable them to survive many different stress conditions.


1992 ◽  
Vol 30 (11) ◽  
pp. 2859-2863 ◽  
Author(s):  
P Domenico ◽  
J L Marx ◽  
P E Schoch ◽  
B A Cunha

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Clarence M. Ongkudon ◽  
Jia Han Chew ◽  
Boyin Liu ◽  
Michael K. Danquah

Gram-negative bacteria are widely used for the production of gene-based products such as DNA vaccines and bio-drugs, where endotoxin contamination can occur at any point within the process and its removal is of great concern. In this article, we review the structures of endotoxin and the effects that it causes in vivo. The endotoxin removal strategies are also discussed in the light of the different interaction mechanisms involved between endotoxins and bioproducts particularly plasmid DNA and proteins. For most cases, endotoxin removal is favoured at a highly ionic or acidic condition. Various removal methods particularly chromatography-based techniques are covered in this article according to the relevant applications.


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