scholarly journals Occurrence of Multiple Antibiotic Resistant Bacteria in Aquatic Environments in Central Minnesota

2015 ◽  
Vol 12 (3) ◽  
Author(s):  
Megan Bollin ◽  
Ellen Jensen ◽  
David Mitchell
Keyword(s):  
Aquatic Ecosystems ◽  
Resistant Bacteria ◽  
Aquatic Environments ◽  
Gram Negative Bacteria ◽  
Drug Resistant ◽  
Antibiotic Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Gram Negative ◽  
Density Values ◽  
Resistance Coefficients

The purpose of this study was to investigate the possibility that antibiotic resistant bacteria could be isolated and identified in aquatic ecosystems in the lakes on the campus of Saint John’s University and the nearby Sauk and Watab Rivers. A total of 125 isolates were collected. Seventy-nine percent of the isolates were gram negative rods. Twenty-six isolates that were resistant to seven or more antibiotics were selected for further investigation. The 26 isolates were all gram negative and members of seven different genera with Flavobacterium and Acinetobacter being the most common. Resistance coefficients were calculated based on optical density values relative to cells grown without antibiotics. Multi-drug resistant, gram negative bacteria were shown to be common in aquatic environments in central Minnesota.

scholarly journals Synergism between Outer Membrane Proteins and Antimicrobials

2011 ◽  
Vol 55 (5) ◽  
pp. 2206-2211 ◽  
Author(s):  
P. Veiga-Crespo ◽  
E. Fusté ◽  
T. Vinuesa ◽  
M. Viñas ◽  
T. G. Villa
Keyword(s):  
Outer Membrane ◽  
Outer Membrane Proteins ◽  
Bactericidal Effect ◽  
Resistant Bacteria ◽  
Logarithmic Phase ◽  
Permeability Barrier ◽  
Gram Negative Bacteria ◽  
Antibiotic Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Gram Negative

ABSTRACTAntibiotic-resistant bacteria are becoming one of the most important problems in health care because of the number of resistant strains and the paucity of new effective antimicrobials. Since antibiotic-resistant bacteria will continue to increase, it is necessary to look for new alternative strategies to fight against them. It is generally accepted that Gram-negative bacteria are intrinsically less susceptible than Gram-positive bacteria to antimicrobials. The main reason is that Gram-negative bacteria are surrounded by a permeability barrier known as the outer membrane (OM). Hydrophilic solutes most often cross the OM through water-filled channels formed by a particular family of proteins known as porins. This work explores the possibility of using exogenous porins to lower the required amounts of antibiotics (ampicillin, ciprofloxacin, cefotaxime, clindamycin, erythromycin, and tetracycline). Porins had a bactericidal effect onEscherichia colicultures, mainly in the logarithmic phase of growth, when combined with low antibiotic concentrations. The use of different antibiotic-porin mixtures showed a bactericidal effect greater than those of antibiotics and porins when used separately. It was possible to observe different behaviors according to the antibiotic type used.

scholarly journals Lysophosphatidylcholine Potentiates Antibacterial Activity of Polymyxin B

2020 ◽  
Vol 64 (12) ◽  
Author(s):  
Jitender Yadav ◽  
Sana Ismaeel ◽  
Ayub Qadri
Keyword(s):  
Antibacterial Activity ◽  
Polymyxin B ◽  
Resistant Bacteria ◽  
Bacterial Membrane ◽  
Gram Negative Bacteria ◽  
Drug Resistant ◽  
Antibiotic Resistant ◽  
Gram Negative ◽  
Drug Resistant Bacteria

ABSTRACT Polymyxin B, used to treat infections caused by antibiotic-resistant Gram-negative bacteria, produces nephrotoxicity at its current dosage. We show that a combination of nonbactericidal concentration of this drug and lysophosphatidylcholine (LPC) potently inhibits growth of Salmonella and at least two other Gram-negative bacteria in vitro. This combination makes bacterial membrane porous and causes degradation of DnaK, the regulator of protein folding. Polymyxin B-LPC combination may be an effective and safer regimen against drug-resistant bacteria.

scholarly journals Antibiotic Resistance and Virulence Profiles of Gram-Negative Bacteria Isolated from Loggerhead Sea Turtles (Caretta Caretta) of the Island of Maio, Cape Verde

2021 ◽  
Author(s):  
Matilde Costa Fernandes ◽  
Miguel L. Grilo ◽  
Eva Cunha ◽  
Carla Carneiro ◽  
Luís Tavares ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Pathogenic Bacteria ◽  
Sea Turtles ◽  
Caretta Caretta ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Antibiotic Resistant Bacteria ◽  
Loggerhead Sea Turtles ◽  
Antibiotic Resistant ◽  
Gram Negative

Abstract Background: Several studies detected high levels of antibiotic-resistance in loggerhead sea turtles (Caretta caretta) and pointed this species as prime reservoirs of antibiotic-resistant bacteria and carriers of potentially pathogenic bacteria. This study aimed to characterize, for the first time, the Gram-negative aerobic microbiota of the Cape Verdean loggerhead subpopulation. Cloacal, oral and egg content swab samples from 33 nesting loggerheads (n = 99) of the Island of Maio were analysed regarding the presence of Gram-negative bacteria and their antibiotic resistance and virulence profiles. Results: Shewanella putrefaciens (27.78%), Morganella morganii (22.22%) and Vibrio alginolyticus (22.22%) were the most prevalent species isolated from the animals under study. A low incidence of antibiotic-resistant bacteria (26%) was detected, and no multidrug-resistant isolates were identified. Non-Enterobacteriaceae isolates presented the most complex virulence profiles, revealing the ability to produce hemolysins (100%), DNases (89%), lipases (79%), proteases (53%), lecithinases (21%), gelatinases (16%), and also biofilms (74%). Moreover, higher virulence indices were obtained for turtles with high parasite intensities compared with apparently healthy animals, and a positive correlation between antibiotic resistance and virulence was observed. Conclusions: Results suggest that this loggerhead population may be less exposed to antimicrobial compounds, probably due to the low anthropogenic impact observed in both their nesting (the Island of Maio) and foraging sites. Nevertheless, the presence of potentially pathogenic bacteria expressing virulence factors may threat both sea turtles’ and humans’ health.

scholarly journals Battacin (Octapeptin B5), a New Cyclic Lipopeptide Antibiotic from Paenibacillus tianmuensis Active against Multidrug-Resistant Gram-Negative Bacteria

2011 ◽  
Vol 56 (3) ◽  
pp. 1458-1465 ◽  
Author(s):  
Chao-Dong Qian ◽  
Xue-Chang Wu ◽  
Yi Teng ◽  
Wen-Peng Zhao ◽  
Ou Li ◽  
...  
Keyword(s):  
Polymyxin B ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Drug Resistant ◽  
Antibiotic Resistant ◽  
Gram Negative ◽  
Content Type ◽  
Lipopeptide Antibiotic

ABSTRACTHospital-acquired infections caused by drug-resistant bacteria are a significant challenge to patient safety. Numerous clinical isolates resistant to almost all commercially available antibiotics have emerged. Thus, novel antimicrobial agents, specifically those for multidrug-resistant Gram-negative bacteria, are urgently needed. In the current study, we report the isolation, structure elucidation, and preliminary biological characterization of a new cationic lipopeptide antibiotic, battacin or octapeptin B5, produced from aPaenibacillus tianmuensissoil isolate. Battacin kills bacteriain vitroand has potent activity against Gram-negative bacteria, including multidrug-resistant and extremely drug-resistant clinical isolates. Hospital strains ofEscherichia coliandPseudomonas aeruginosaare the pathogens most sensitive to battacin, with MICs of 2 to 4 μg/ml. The ability of battacin to disrupt the outer membrane of Gram-negative bacteria is comparable to that of polymyxin B, the last-line therapy for infections caused by antibiotic-resistant Gram-negative bacteria. However, the capacity of battacin to permeate bacterial plasma membranes is less extensive than that of polymyxin B. The bactericidal kinetics of battacin correlate with the depolarization of the cell membrane, suggesting that battacin kills bacteria by disrupting the cytoplasmic membrane. Other studies indicate that battacin is less acutely toxic than polymyxin B and has potentin vivobiological activity againstE. coli. Based on the findings of the current study, battacin may be considered a potential therapeutic agent for the treatment of infections caused by antibiotic-resistant Gram-negative bacteria.

scholarly journals A Degradation Product from Hydrolysate of Imipenem with Imis Broad-Spectrum Inhibits Metallo-β-Lactamases

2020 ◽  
Vol 13 (10) ◽  
Author(s):  
Ying Ge ◽  
Li-Wei Xu ◽  
Jian-Bin Zhen ◽  
Cheng Chen ◽  
Miao Lv ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Degradation Product ◽  
Substrate Inhibition ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Antibiotic Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Leaving Group ◽  
Ic50 Values ◽  
Hydrolysis Of

Background: Infections caused by metallo-β-lactamases (MβLs)-producing antibiotic-resistant bacteria pose a severe threat to public health. The synergistic use of current antibiotics in combination with MβL inhibitors is a promising therapeutic mode against these antibiotic-resistant bacteria. Objectives: The study aimed to probe the inhibition of MβLs and obtain the active component, P1, in the degradation product after imipenem was hydrolyzed by ImiS. Methods: The hydrolysis of two carbapenems with MβL ImiS was monitored by UV-Vis in real-time, and the degradation product from the leaving group produced after imipenem was hydrolyzed (but not for faropenem) was purified by HPLC to give one component, P1. Results: Kinetic assays revealed that P1 exhibited a broad-spectrum inhibition against VIM-2, NDM-1, ImiS, and L1, from three sub-classes of MβLs, with IC50 values of 8 - 32, 13.8 - 29.3, and 14.2 - 19.2 µM, using imipenem, cefazolin, and nitrocefin as substrates, respectively. Also, P1 showed synergistic antibacterial efficacy against drug-resistant Escherichia coli producing VIM-2, NDM-1, ImiS, and L1, in combination with antibiotics, restoring 16 to 32-fold and 32 to 128-fold efficacies of imipenem and cefazolin, respectively. Spectroscopic and Ellman's reagent analyses suggested that P1, a mercaptoethyl-form imidamide, is a mechanism-based inhibitor, while faropenem has no substrate inhibition, due to the lack of a leaving group. Conclusions: This work reveals that the hydrolysate of imipenem, a carbapenem with a good leaving group, can be used in screening for broad-spectrum inhibitors of MβLs.

scholarly journals Antibiotic Resistance of Gram-Negative Bacteria from Wild Captured Loggerhead Sea Turtles

Antibiotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 162 ◽  
Author(s):  
Monica Francesca Blasi ◽  
Luciana Migliore ◽  
Daniela Mattei ◽  
Alice Rotini ◽  
Maria Cristina Thaller ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Sea Turtles ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Marine Animals ◽  
Loggerhead Sea Turtles ◽  
Antibiotic Resistant ◽  
Gram Negative ◽  
Marine Habitats ◽  
Resistant Strains

Sea turtles have been proposed as health indicators of marine habitats and carriers of antibiotic-resistant bacterial strains, for their longevity and migratory lifestyle. Up to now, a few studies evaluated the antibacterial resistant flora of Mediterranean loggerhead sea turtles (Caretta caretta) and most of them were carried out on stranded or recovered animals. In this study, the isolation and the antibiotic resistance profile of 90 Gram negative bacteria from cloacal swabs of 33 Mediterranean wild captured loggerhead sea turtles are described. Among sea turtles found in their foraging sites, 23 were in good health and 10 needed recovery for different health problems (hereafter named weak). Isolated cloacal bacteria belonged mainly to Enterobacteriaceae (59%), Shewanellaceae (31%) and Vibrionaceae families (5%). Although slight differences in the bacterial composition, healthy and weak sea turtles shared antibiotic-resistant strains. In total, 74 strains were endowed with one or multi resistance (up to five different drugs) phenotypes, mainly towards ampicillin (~70%) or sulfamethoxazole/trimethoprim (more than 30%). Hence, our results confirmed the presence of antibiotic-resistant strains also in healthy marine animals and the role of the loggerhead sea turtles in spreading antibiotic-resistant bacteria.

scholarly journals Antibiotic-Resistant Gram-Negative Bacteria in Birds From the Brazilian Atlantic Forest

The Condor ◽  
2003 ◽  
Vol 105 (2) ◽  
pp. 358-361 ◽  
Author(s):  
Andréa M. A. Nascimento ◽  
Luciana Cursino ◽  
Higgor Gonçalves-Dornelas ◽  
Andrea Reis ◽  
Edmar Chartone-Souza ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Kanamycin Resistance ◽  
Minas Gerais ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Brazilian Atlantic Forest ◽  
Antibiotic Resistant ◽  
Gram Negative ◽  
Resistant Phenotype ◽  
Animal Farms

Abstract We evaluated the antibiotic resistance of bacteria isolated from cloacal swabs of wild birds collected with mist nets in the Jequitinhonha river valley, in the state of Minas Gerais, Brazil. A total of 191 isolates from 19 individuals of 16 species was obtained and tested for resistance to five antibiotics. At Salto da Divisa 97% of the isolates exhibited a resistant phenotype, and resistance to more than one antibiotic was frequent (71%). At Jequitinhonha 36% of isolates were resistant, but 94% showed resistance to only one antibiotic. Of the five antibiotics tested, resistance to ampicillin was most frequent (in both areas), whereas kanamycin resistance was found in only one isolate. The data here obtained and other data reported in the literature show that the general premise that antibiotic-resistant bacteria arise primarily in hospitals or animal farms should be reconsidered. Bactérias Gram-Negativas Resistentes a Antibióticos em Aves da Mata Atlântica Brasileira Resumo. Avaliamos a resistência a antibióticos de bactérias isoladas por swab cloacal em aves selvagens capturadas com redes de neblina em duas regiões do Vale do Rio Jequitinhonha, Minas Gerais, Brasil. Foram obtidos 191 isolados de 19 indivíduos de 16 espécies e foi testada a resistência desses isolados a cinco antibióticos. Em Salto da Divisa, 97% dos isolados exibiram fenótipo resistente e foi freqüente (71%) a resistência a mais de um antibiótico. Em Jequitinhonha, 36% dos isolados exibiram fenótipo resistente, dos quais 94% apresentaram resistência a apenas um antibiótico. Em ambas as áreas, a maioria dos isolados apresentou resistência à ampicilina, enquanto somente um único isolado foi resistente à canamicina. Os dados aqui obtidos e outros relatados na literatura mostram que a premissa geral de que bactérias resistentes a antibióticos surgem principalmente em hospitais ou fazendas de animais deve ser reconsiderada.

Antibiotic contamination and occurrence of antibiotic-resistant bacteria in aquatic environments of northern Vietnam

2011 ◽  
Vol 409 (15) ◽  
pp. 2894-2901 ◽  
Author(s):  
Phan Thi Phuong Hoa ◽  
Satoshi Managaki ◽  
Norihide Nakada ◽  
Hideshige Takada ◽  
Akiko Shimizu ◽  
...  
Keyword(s):  
Resistant Bacteria ◽  
Aquatic Environments ◽  
Antibiotic Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Northern Vietnam

scholarly journals Nosocomial klebsiellas: I. Colonization of hospitalized patients

1979 ◽  
Vol 82 (2) ◽  
pp. 177-193 ◽  
Author(s):  
Michael L. Haverkorn ◽  
M. F. Michel
Keyword(s):  
Gram Negative Bacteria ◽  
Drug Resistant ◽  
Biochemical Tests ◽  
Survey Period ◽  
Antibiotic Resistant ◽  
Gram Negative ◽  
Epidemiological Tool ◽  
Resistant Strains ◽  
Drug Resistant Strains ◽  
Systemic Antibiotics

SUMMARYThe colonization of patients byKlebsiellaand several other gram-negative bacteria was studied in a hospital urological ward over a period of six months. Before and during the survey there was no evidence of an outbreak of nosocomial infection and multi-drug resistant strains ofKlebsiellawere not isolated.Klebsiellawere biotyped by nine biochemical tests, which led to the detection of 66 biotypes spread uniformly throughout the survey period. This method of biotyping proved a useful epidemiological tool. The colonization rate of throats, hands, and faeces of patients increased after admission to the ward, especially when antibiotics were used. The effect of systemic antibiotics was greater than that of urinary antibiotics especially on throat and faeces carrier rates. Carrier rates forKlebsiellaincreased also after catheterization and operation – relationships which could well be multifactorial.During the first two weeks after admission the proportion of antibiotic resistant strains ofKlebsiellain carriers increased. The proportion of resistant strains amongst isolations from clinical infections was always greater than among strains isolated routinely from sites of carriage.

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