scholarly journals Natural Antibiotic Resistance of Bacteria Isolated from Larvae of the Oil Fly, Helaeomyia petrolei

2000 ◽  
Vol 66 (11) ◽  
pp. 4615-4619 ◽  
Author(s):  
Dana R. Kadavy ◽  
Jacob M. Hornby ◽  
Terry Haverkost ◽  
Kenneth W. Nickerson
Keyword(s):  
Antibiotic Resistance ◽  
Los Angeles ◽  
Nalidixic Acid ◽  
Antimicrobial Agents ◽  
Efflux Pump ◽  
Gut Contents ◽  
Solvent Tolerance ◽  
Bacterial Strains ◽  
Active Efflux ◽  
Mutator Strain

ABSTRACT Helaeomyia petrolei (oil fly) larvae inhabit the asphalt seeps of Rancho La Brea in Los Angeles, Calif. The culturable microbial gut contents of larvae collected from the viscous oil were recently examined, and the majority (9 of 14) of the strains were identified as Providencia spp. Subsequently, 12 of the bacterial strains isolated were tested for their resistance or sensitivity to 23 commonly used antibiotics. All nine strains classified as Providencia rettgeri exhibited dramatic resistance to tetracycline, vancomycin, bacitracin, erythromycin, novobiocin, polymyxin, colistin, and nitrofurantoin. Eight of nineProvidencia strains showed resistance to spectinomycin, six of nine showed resistance to chloramphenicol, and five of nine showed resistance to neomycin. All 12 isolates were sensitive to nalidixic acid, streptomycin, norfloxacin, aztreonam, cipericillin, pipericillin, and cefotaxime, and all but OF008 (Morganella morganii) were sensitive to ampicillin and cefoxitin. The oil fly bacteria were not resistant to multiple antibiotics due to an elevated mutation rate. For each bacterium, the number of resistant mutants per 108cells was determined separately on rifampin, nalidixic acid, and spectinomycin. In each case, the average frequencies of resistant colonies were at least 50-fold lower than those established for known mutator strain ECOR 48. In addition, the oil fly bacteria do not appear to excrete antimicrobial agents. When tested, none of the oil fly bacteria produced detectable zones of inhibition on Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, or Candida albicans cultures. Furthermore, the resistance properties of oil fly bacteria extended to organic solvents as well as antibiotics. When pre-exposed to 20 μg of tetracycline per ml, seven of nine oil fly bacteria tolerated overlays of 100% cyclohexane, six of nine tolerated 10% xylene, benzene, or toluene (10:90 in cyclohexane), and three of nine (OF007, OF010, and OF011) tolerated overlays of 50% xylene–50% cyclohexane. The observed correlation between antibiotic resistance and organic solvent tolerance is likely explained by an active efflux pump that is maintained in oil fly bacteria by the constant selective pressure of La Brea's solvent-rich environment. We suggest that the oil fly bacteria and their genes for solvent tolerance may provide a microbial reservoir of antibiotic resistance genes.

The Activity of Alkanna Species in vitro Culture and Intact Plant Extracts Against Antibiotic Resistant Bacteria

2019 ◽  
Vol 25 (16) ◽  
pp. 1861-1865 ◽  
Author(s):  
Naira Sahakyan ◽  
Margarit Petrosyan ◽  
Armen Trchounian
Keyword(s):  
Antibiotic Resistance ◽  
Antibacterial Agents ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Resistant Bacteria ◽  
Plant Origin ◽  
Bacterial Strains ◽  
Biotechnological Production ◽  
Antibiotic Resistant

Overcoming the antibiotic resistance is nowadays a challenge. There is still no clear strategy to combat this problem. Therefore, the urgent need to find new sources of antibacterial agents exists. According to some literature, substances of plant origin are able to overcome bacterial resistance against antibiotics. Alkanna species plants are among the valuable producers of these metabolites. But there is a problem of obtaining the standardized product. So, this review is focused on the discussion of the possibilities of biotechnological production of antimicrobial agents from Alkanna genus species against some microorganisms including antibiotic resistant bacterial strains.

scholarly journals Characterisation of antibiotic resistance ofSalmonellaisolated from dog treats in Japan

2019 ◽  
Vol 147 ◽  
Author(s):  
S. Yukawa ◽  
I. Uchida ◽  
Y. Tamura ◽  
S. Ohshima ◽  
T. Hasegawa
Keyword(s):  
Antibiotic Resistance ◽  
Nalidixic Acid ◽  
Salmonella Enterica ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Surveillance Data ◽  
Potential Source ◽  
Human Salmonellosis ◽  
The Usa

AbstractDog treats might be contaminated withSalmonella. In Canada and the USA, outbreaks of human salmonellosis related to exposure to animal-derived dog treats were reported. Consequently, surveillance data onSalmonellacontamination of dog treats have been gathered in many countries, but not in Japan. In the current study, we investigated whether dog treats in Japan were contaminated withSalmonella. Overall, 303 dog treats (of which 255 were domestically produced) were randomly collected and the presence ofSalmonellainvestigated. Seven samples were positive forSalmonella entericasubsp.enterica. Among these isolates, three were identified as serovar 4,5,12:i:–; two were serovar Rissen; and two were serovar Thompson. All serovar 4,5,12:i:– and Thompson isolates were resistant to one or more drugs. Two serovar Rissen isolates were fully susceptible to all tested antimicrobial agents. AllSalmonellaisolates were susceptible to cefotaxime, ciprofloxacin and nalidixic acid. The geneblaTEMwas detected in two serovar 4,5,12:i:– isolates. TheblaCTX−MandblaCMYgenes were not detected in any isolates. This study demonstrated that dog treats in Japan could constitute a potential source of dog and humanSalmonellainfections, including multidrug-resistantSalmonellaisolates.

Characterization of the Serratia marcescens SdeCDE multidrug efflux pump studied via gene knockout mutagenesis

2008 ◽  
Vol 54 (5) ◽  
pp. 411-416 ◽  
Author(s):  
Sanela Begic ◽  
Elizabeth A. Worobec
Keyword(s):  
Antibiotic Resistance ◽  
Substrate Specificity ◽  
Serratia Marcescens ◽  
Efflux Pump ◽  
Gene Knockout ◽  
Multidrug Efflux ◽  
Multidrug Efflux Pump ◽  
Active Efflux ◽  
Major Mechanism

Serratia marcescens is an important nosocomial agent having high antibiotic resistance. A major mechanism for S. marcescens antibiotic resistance is active efflux. To ascertain the substrate specificity of the S. marcescens SdeCDE efflux pump, we constructed pump gene deletion mutants. sdeCDE knockout strains showed no change in antibiotic susceptibility in comparison with the parental strains for any of the substrates, with the exception of novobiocin. In addition, novobiocin was the only antibiotic to be accumulated by sdeCDE-deficient strains. Based on the substrates used in our study, we conclude that SdeCDE is a Resistance–Nodulation–Cell Division family pump with limited substrate specificity.

Antimicrobials: Modes of Action and Mechanisms of Resistance

2003 ◽  
Vol 22 (2) ◽  
pp. 135-143 ◽  
Author(s):  
Patrick F. Mc Dermott ◽  
Robert D. Walker ◽  
David G. White
Keyword(s):  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Antimicrobial Agents ◽  
Bacterial Pathogens ◽  
Animal Health ◽  
Animal Origin ◽  
Mobile Dna ◽  
Genetic Event ◽  
Active Efflux ◽  
Dna Elements

After six decades of widespread antibiotic use, bacterial pathogens of human and animal origin are becoming increasingly resistant to many antimicrobial agents. Antimicrobial resistance develops through a limited number of mechanisms: (a) permeability changes in the bacterial cell wall/membrane, which restrict antimicrobial access to target sites; (b) active efflux of the antimicrobial from the cell; (c) mutation in the target site; (d) enzymatic modification or degradation of the antimicrobial; and (e) acquisition of alternative metabolic pathways to those inhibited by the drug. Numerous bacterial antimicrobial resistance phenotypes result from the acquisition of external genes that may provide resistance to an entire class of antimicrobials. These genes are frequently associated with large transferable extrachromosomal DNA elements called plasmids, on which may be other mobile DNA elements such as transposons and integrons. An array of different resistance genes may accumulate on a single mobile element, presenting a situation in which multiple antibiotic resistance can be acquired via a single genetic event. The versatility of bacterial populations in adapting to toxic environments, along with their facility in exchanging DNA, signifies that antibiotic resistance is an inevitable biological phenomenon that will likely continue to be a chronic medical problem. Successful management of current antimicrobials, and the continued development of new ones, is vital to protecting human and animal health against bacterial pathogens.

scholarly journals Antimicrobial Susceptibility and Mechanisms of Resistance in Shigella and Salmonella Isolates from Children under Five Years of Age with Diarrhea in Rural Mozambique

2009 ◽  
Vol 53 (6) ◽  
pp. 2450-2454 ◽  
Author(s):  
Inácio Mandomando ◽  
Dinis Jaintilal ◽  
Maria J. Pons ◽  
Xavier Vallès ◽  
Mateu Espasa ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Nalidixic Acid ◽  
Antimicrobial Susceptibility ◽  
Molecular Mechanisms ◽  
Antimicrobial Agents ◽  
Shigella Flexneri ◽  
Colorimetric Method ◽  
Multidrug Resistant ◽  
Mechanisms Of Resistance ◽  
First Line

ABSTRACT The antimicrobial susceptibility and mechanisms of resistance of 109 Shigella and 40 Salmonella isolates from children with diarrhea in southern Mozambique were assessed. The susceptibility to seven antimicrobial agents was tested by disk diffusion, and mechanisms of resistance were searched by PCR or colorimetric method. A high proportion of Shigella isolates were resistant to chloramphenicol (Chl) (52%), ampicillin (Amp) (56%), tetracycline (Tet) (66%), and trimethoprim-sulfamethoxazole (Sxt) (84%). Sixty-five percent of the isolates were multidrug resistant. Shigella flexneri isolates were more resistant than those of Shigella sonnei to Amp (66% versus 0.0%, P < 0.001) and Chl (61% versus 0.0%, P < 0.001), whereas S. sonnei isolates presented higher resistance to Tet than S. flexneri isolates (93% versus 64%, P = 0.02). Resistance among Salmonella isolates was as follows: Tet and Chl, 15% each; Sxt, 18%; and Amp, 25%. Only 3% of Salmonella isolates were resistant to nalidixic acid (Nal), and none to ciprofloxacin or ceftriaxone (Cro). Among Salmonella isolates, multiresistance was found in 23%. Among Shigella isolates, antibiotic resistance was related mainly to the presence of oxa-1-like β-lactamases for Amp, dfrA1 genes for Sxt, tetB genes for Tet, and Chl acetyltransferase (CAT) activity for Chl. Among Salmonella isolates, resistance was conferred by tem-like β-lactamases for Amp, floR genes and CAT activity for Chl, tetA genes for Tet, and dfrA1 genes for Sxt. Our data show that Shigella isolates are resistant mostly to the most available, inexpensive antibiotics by various molecular mechanisms but remain susceptible to ciprofloxacin, Cro, and Nal, which is the first line for empirical treatment of shigellosis in the country.

scholarly journals Expanding multiple antibiotic resistance among clinical strains of Vibrio cholerae isolated from 1992–7 in Calcutta, India

2000 ◽  
Vol 124 (3) ◽  
pp. 393-399 ◽  
Author(s):  
P. GARG ◽  
S. CHAKRABORTY ◽  
I. BASU ◽  
S. DATTA ◽  
K. RAJENDRAN ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Infectious Diseases ◽  
Nalidixic Acid ◽  
Vibrio Cholerae ◽  
Antimicrobial Agents ◽  
Gradual Increase ◽  
Initial Increase ◽  
Multiple Antibiotic Resistance ◽  
Ampicillin Resistance ◽  
Changing Trends

Antimicrobial susceptibilities of Vibrio cholerae strains isolated from cholera patients admitted to the Infectious Diseases Hospital, Calcutta, India for 6 years were analysed to determine the changing trends; 840 V. cholerae strains isolated in 1992–1997 were included in this study. Among V. cholerae serogoup O1 and O139, ampicillin resistance increased from 1992 (35 and 70%, respectively) to 1997 (both serogroups 100%). Resistance to furazolidone and streptomycin was constantly high among V. cholerae O1 strains with gradual increase in resistance to other drugs such as ciprofloxacin, co-trimoxazole, neomycin and nalidixic acid. V. cholerae O139 strains exhibited susceptibilities to furazolidone and streptomycin comparable with those of O1 strains. However, after initial increase in resistance to chloramphenicol and co-trimoxazole, all the V. cholerae O139 strains became susceptible to these two drugs from 1995 onwards. Both V. cholerae O1 and O139 remained largely susceptible to gentamicin and tetracycline. V. cholerae non-O1, non-O139 strains, in contrast, exhibited high levels of resistance to virtually every class of antimicrobial agents tested in this study especially from 1995. Kruskal–Wallis one-way analysis showed that V. cholerae O1 Ogawa serogroup exhibited significant yearly increase in resistance to nine antibiotics followed by non-O1 non-O139 and O139 strains to six antibiotics and two antibiotics respectively. Interesting observation encountered in this study was the dissipation of some of the resistant patterns commonly found among V. cholerae non-O1 non-O139 or O1 serogroups to the O139 serogroup and vice versa during the succeeding years.

scholarly journals Detection of Salmonella spp. in Retail Raw Food Samples from Vietnam and Characterization of Their Antibiotic Resistance

2007 ◽  
Vol 73 (21) ◽  
pp. 6885-6890 ◽  
Author(s):  
Thi Thu Hao Van ◽  
George Moutafis ◽  
Taghrid Istivan ◽  
Linh Thuoc Tran ◽  
Peter J. Coloe
Keyword(s):  
Antibiotic Resistance ◽  
Nalidixic Acid ◽  
Gene Cluster ◽  
Resistance Gene ◽  
Antimicrobial Agents ◽  
Genomic Island ◽  
Antibiotic Resistance Gene ◽  
Food Samples ◽  
Salmonella Spp

ABSTRACT A study was conducted to examine the levels of Salmonella spp. contamination in raw food samples, including chicken, beef, pork, and shellfish, from Vietnam and to determine their antibiotic resistance characteristics. A total of 180 samples were collected and examined for the presence of Salmonella spp., yielding 91 Salmonella isolates. Sixty-one percent of meat and 18% of shellfish samples were contaminated with Salmonella spp. Susceptibility of all isolates to a variety of antimicrobial agents was tested, and resistance to tetracycline, ampicillin/amoxicillin, nalidixic acid, sulfafurazole, and streptomycin was found in 40.7%, 22.0%, 18.7%, 16.5%, and 14.3% of the isolates, respectively. Resistance to enrofloxacin, trimethoprim, chloramphenicol, kanamycin, and gentamicin was also detected (8.8 to 2.2%). About half (50.5%) of the isolates were resistant to at least one antibiotic, and multiresistant Salmonella isolates, resistant to at least three different classes of antibiotics, were isolated from all food types. One isolate from chicken (serovar Albany) contained a variant of the Salmonella genomic island 1 antibiotic resistance gene cluster. The results show that antibiotic resistance in Salmonella spp. in raw food samples from Vietnam is significant.

scholarly journals Induction of Multidrug Resistance Mechanism in Escherichia coli Biofilms by Interplay between Tetracycline and Ampicillin Resistance Genes

2009 ◽  
Vol 53 (11) ◽  
pp. 4628-4639 ◽  
Author(s):  
Thithiwat May ◽  
Akinobu Ito ◽  
Satoshi Okabe
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antimicrobial Agents ◽  
Efflux Pump ◽  
Marker Genes ◽  
Ampicillin Resistance ◽  
High Level ◽  
Biofilm Development ◽  
Level Resistance

ABSTRACT Biofilms gain resistance to various antimicrobial agents, and the presence of antibiotic resistance genes is thought to contribute to a biofilm-mediated antibiotic resistance. Here we showed the interplay between the tetracycline resistance efflux pump TetA(C) and the ampicillin resistance gene (bla TEM-1) in biofilms of Escherichia coli harboring pBR322 in the presence of the mixture of ampicillin and tetracycline. E. coli in the biofilms could obtain the high-level resistance to ampicillin, tetracycline, penicillin, erythromycin, and chloramphenicol during biofilm development and maturation as a result of the interplay between the marker genes on the plasmids, the increase of plasmid copy number, and consequently the induction of the efflux systems on the bacterial chromosome, especially the EmrY/K and EvgA/S pumps. In addition, we characterized the overexpression of the TetA(C) pump that contributed to osmotic stress response and was involved in the induction of capsular colanic acid production, promoting formation of mature biofilms. However, this investigated phenomenon was highly dependent on the addition of the subinhibitory concentrations of antibiotic mixture, and the biofilm resistance behavior was limited to aminoglycoside antibiotics. Thus, marker genes on plasmids played an important role in both resistance of biofilm cells to antibiotics and in formation of mature biofilms, as they could trigger specific chromosomal resistance mechanisms to confer a high-level resistance during biofilm formation.

scholarly journals Serratia marcescens RamA expression is under PhoP-dependent control and modulates lipid A-related genes transcription and antibiotic resistance phenotypes

2021 ◽  
Author(s):  
Javier F. Mariscotti ◽  
Eleonora García Véscovi
Keyword(s):  
Antibiotic Resistance ◽  
Serratia Marcescens ◽  
Nalidixic Acid ◽  
Lipid A ◽  
Efflux Pump ◽  
Transcriptional Regulator ◽  
Opportunistic Pathogen ◽  
Binding Motif ◽  
Promoter Regions ◽  
Wide Range

Serratia marcescens is an enteric bacterium that can function as an opportunistic pathogen with with increasing incidence in clinical settings. This is mainly due to the ability of express a wide range of virulence factors and the acquisition of antibiotic resistance mechanisms. For these reasons, S. marcescens has been declared by the WHO as a research priority to develop alternative antimicrobial strategies. In this work, we found a PhoP-binding motif in the promoter region of transcriptional regulator RamA of the S. marcescens RM66262. We demonstrated that the expression of ramA is autoregulated and that ramA is also part of the PhoP/PhoQ regulon. We have also shown that PhoP binds directly and specifically to ramA, mgtE1, mgtE2, lpxO1 and lpxO2 promoter regions and that RamA binds to ramA and lpxO1 but not to mgtE1 and lpxO2, suggesting an indirect control for these latter genes. Finally, we have demonstrated that, in S. marcescens, the RamA overexpression induces the AcrAB-TolC efflux pump required to reduce the susceptibility of the bacteria to tetracycline and nalidixic acid. In sum, we herein show the first report describing the regulation of ramA under the PhoP/PhoQ regulon, and the regulatory role of RamA in S. marcescens. Importance We demonstrate that, in S. marcescens, the transcriptional regulator RamA is autoregulated and also controlled by the PhoP/PhoQ signal transduction system. We have shown that PhoP is able to directly and specifically bind to ramA, mgtE1, mgtE2, lpxO1 and lpxO2 promoter regions. In addition, RamA is able to directly interact with the promoter regions of ramA, lpxO1 but indirectly regulates mgtE1 and lpxO2. Finally, we found that, in S. marcescens, RamA overexpression induces the AcrAB-TolC efflux pump required to reduce susceptibility to tetracycline and nalidixic acid. Collectively, these results further our understanding of PhoP/PhoQ regulon in S. marcescens and demonstrate the involvement of RamA in the protection against antibiotic challenges.

scholarly journals Antistaphylococcal and Antibiotic Resistance Modulatory Activities of Thirteen Cameroonian Edible Plants against Resistant Phenotypes

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Brice E. N. Wamba ◽  
Armelle T. Mbaveng ◽  
Paul Nayim ◽  
Joachim K. Dzotam ◽  
Ornella J. T. Ngalani ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Edible Plants ◽  
Bacterial Strains ◽  
Efflux Pump Inhibitor ◽  
Dacryodes Edulis

Background. In this study, 18 methanol extracts from Cameroonian edible plants were tested for their antibacterial activities against 26 strains ofS. aureus; the role of efflux pumps in the resistance of tested bacteria and the antibiotic resistance-modulating activities against selected multidrug-resistant (MDR) phenotypes were also investigated.Methods. Broth microdilution assay was used to evaluate the antibacterial activity, the role of efflux pumps, and the antibiotic resistance-modulating effects of plant extracts.Results. Extracts fromDacryodes edulisseeds (DES) andDacryodes edulisbark (DEB) were active against all 26 tested bacterial strains, within the minimal inhibitory concentration (MIC) range of 256–1024 µg/mL. MIC values varied from 64 to 1024 µg/mL against 96.2% of the 26 tested bacteria forPhaseolus vulgarisleaves (PVL), 92.3% forAzadirachta indicabark (AIB),Dacryodes edulisleaves (DEL), andRicinodendron heudelotiileaves (RHL). The lowest MIC value of 64 µg/mL was obtained with the extract fromCucurbita maximabeans (CMB) against MRSA4 strain and fromUapaca guineensisbark (UGB) against MRSA9 strain. Bacterial efflux pump inhibitor (EPI), carbonyl cyanidem-chlorophenyl hydrazone (CCCP), improved the activity of DES and UGB as well as that of extracts fromHibiscus esculentusleaves (HEL) andUapaca guineensisleaves (UGL) against resistantS. aureusstrains. Antibiotic-modulating effects against more than 70% of theS. aureusstrains tested were obtained when RHL (at MIC/2) was combined with CIP, ERY, and KAN (88.89%), CHL (88.89%), TET (77.78%), and STR (88.89%).Conclusion. The present study demonstrated that the 13 tested plants had antistaphylococcal effects and that DES, HEL, UGL, and UGB could be used in combination with EPI to combat resistance toStaphylococcus aureus. Also, it demonstrated that some studied extracts and mostly RHL could be used as antibiotic resistance modulators to fight against resistant strains ofS. aureus.

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