Occurrence of Resistance to Antibiotics and Metals and of Plasmids in Bacterial Strains Isolated from Marine Environments

1993 ◽  
Vol 27 (3-4) ◽  
pp. 475-478 ◽  
Author(s):  
M. Avilés ◽  
J. C. Codina ◽  
A. Pérez-García ◽  
F. Cazorla ◽  
P. Romero ◽  
...  

Tlie resistance patterns to different antibiotics and lieavy metals of bacterial strains isolated firom marine environments (seawater, sediments and shellfishes) were studied. Pseudomonas aeruginosa showed the widest resistance profile, both to antibiotics and metals. In general, the resistance profiles of Gram-negative I microorganisms include the resistance to arsenic, copper, amoxycillin and tetracydine. Some associations of resistance to different antimicrobial agents were frequently observed. An important proportion of the studied strains harboured plasmids; and the association between the occurrence of plasmids and the resistance to arsenic, amoxycillin, carbencillin and streptomycin was observed.

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S858-S858
Author(s):  
Monica Maria Rojas Rojas ◽  
Catalina López ◽  
Jaime Ruiz ◽  
Jacquleine Pavía ◽  
Jose Oñate ◽  
...  

Abstract Background The Study for Monitoring Antimicrobial Resistance Trends (SMART) is a worldwide initiative to monitor in vitro susceptibility of clinical Gram-negative isolates to several antimicrobial agents. Surveillance initiatives are essential to provide real-world evidence to support local guidelines development. Colombia has participated since 2012 with isolates from complicated intrabdominal infections (cIAI), complicated urinary tract infections (cUTI) and respiratory tract infections (RTI). This study describes resistant patterns of Escherichia coli (Eco), Klebsiella pneumoniae (Kpn) and Pseudomonas aeruginosa (Pae) clinical isolates collected in Colombian hospitals in a 2 years period (2017–2018). Methods Isolates from patients with cIAI, cUTI and RTI were collected. Identification confirmation was done in central laboratory. Minimum inhibitory concentrations (MIC) were performed by broth microdilution and interpreted according to 2018 CLSI guidelines, same criteria for Extended-spectrum β-lactamase (ESBL) classification. The antimicrobial activity was evaluated for aztreonam (ATM), ceftolozane/tazobactam (C/T), ceftazidime (CAZ), colistin (COL), ertapenem (ETP), cefepime (FEP), imipenem (IMP), meropenem (MEM) and piperacillin–tazobactam (TZP). Results During 2017–2018, 1492 isolates were collected. The main organism was Eco (51%) followed by Kpn (29%) and Pae (20%). In vitro susceptibility activity is presented in Table 1. COL, C/T, ETP, MEM and IPM exhibited over 95% susceptibility in Eco. ESBL prevalence was 18% for Eco (53/314) and 22% for Kpn (36/165). COL and C/T were the most active agents against Pae isolates. For Kpn, MIC50/90 values were: MEM (0.12 / 8), C/T (0.5 / 8) and for TZP (8 / > 64), meanwhile for Pae were MEM (0.5 / 32), C/T (0.5 / 32) and for TZP (8 / > 64). Conclusion Continued antimicrobial resistance surveillance initiatives are critical to guide the empiric treatments decision in a multidrug resistance era. This study shows that Ceftolozane/Tazobactam, MEM and COL have the best susceptibility profile against Eco, Kpn and Pae of cIAI, cUTI and RTI cases in Colombia. The C/T susceptibility rates and low MIC distribution provide evidence to support its use as a non-carbapenem therapeutic alternative for Gram-negative infections. Disclosures All authors: No reported disclosures.


2019 ◽  
Vol 63 (5) ◽  
Author(s):  
Robert K. Flamm ◽  
Paul R. Rhomberg ◽  
Jill M. Lindley ◽  
Kim Sweeney ◽  
E. J. Ellis-Grosse ◽  
...  

ABSTRACT The effects of combining fosfomycin with various antimicrobial agents were evaluated in vitro by broth microdilution checkerboard and time-kill kinetic studies. Checkerboard analyses were used to evaluate the following 30 Gram-negative isolates: 5 Pseudomonas aeruginosa, 5 Acinetobacter baumannii-Acinetobacter calcoaceticus species complex, and 20 Enterobacteriaceae isolates. No isolate exhibited antagonism when fosfomycin was tested in combination, and synergy was observed in more than 25% of the drug combinations tested. The most frequent instances of synergy occurred when testing fosfomycin with β-lactams. Two isolates of Pseudomonas aeruginosa, 2 of Klebsiella pneumoniae, and 1 of the A. baumannii-A. calcoaceticus species complex that exhibited synergy when fosfomycin was tested in combination were subjected to time-kill kinetic analyses for confirmation. Time-kill assays confirmed synergistic activity. These data indicated that combination therapy with fosfomycin may be beneficial.


Author(s):  
Singh Gurvinder ◽  
Singh Prabhsimran ◽  
Dhawan R. K.

In order to develop new antimicrobial agents, a series of 3-formyl indole based Schiff bases were synthesized by reacting 3-formyl indole(indole-3-carboxaldehyde) with substituted aniline taking ethanol as solvent. The reaction was carried in the presence of small amount of p-toluene sulphonic acid as catalyst.All the synthesized compounds were characterized by IR, 1H-NMR spectral analysis. All the synthesized compounds were evaluated for antimicrobial activity against two gram positive bacterial strains (B. subtilisand S. aureus) and two gram negative bacterial strains (P. aeruginosaand E. coli) and one fungal strain (C. albicans). All the synthesized compounds were found to have moderate to good antimicrobial activity. The  standard drug amoxicillin, fluconazole were used for antimicrobial activity. Among the synthesized compounds, the maximum antimicrobial activity was shown by compounds GS04, GS07, GS08 and GS10.


2011 ◽  
Vol 8 (1) ◽  
pp. 305-311 ◽  
Author(s):  
Priyanka Kamaria ◽  
N. Kawathekar ◽  
Prerna Chaturvedi

In order to develop new antimicrobial agents, a series of Schiff bases of indole-3-aldehyde were synthesized by microwave assisted synthesis by takingDMFas solvent and evaluated for their antimicrobial activity. All the synthesized compounds were characterized byIR,1HNMRand mass spectral analysis. All compounds were tested against five gram positive and five gram negative bacterial strains and one fungal strain. All compounds exhibited better activity against gram positive strains than against gram negative strains and the compounds were found more active againstS.aureusandB.subtilis.


2006 ◽  
Vol 50 (2) ◽  
pp. 806-809 ◽  
Author(s):  
Giuseppantonio Maisetta ◽  
Giovanna Batoni ◽  
Semih Esin ◽  
Walter Florio ◽  
Daria Bottai ◽  
...  

ABSTRACT The antimicrobial activity of human β-defensin 3 (hBD-3) against multidrug-resistant clinical isolates of Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Acinetobacter baumannii was evaluated. A fast bactericidal effect (within 20 min) against all bacterial strains tested was observed. The presence of 20% human serum abolished the bactericidal activity of hBD-3 against gram-negative strains and reduced the activity of the peptide against gram-positive strains.


Pathogens ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 75 ◽  
Author(s):  
Wadha Alfouzan ◽  
Rita Dhar ◽  
David Nicolau

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.


Thorax ◽  
2018 ◽  
Vol 74 (1) ◽  
pp. 87-90 ◽  
Author(s):  
Michelle E Wood ◽  
Rebecca E Stockwell ◽  
Graham R Johnson ◽  
Kay A Ramsay ◽  
Laura J Sherrard ◽  
...  

The airborne route is a potential pathway in the person-to-person transmission of bacterial strains among cystic fibrosis (CF) populations. In this cross-sectional study, we investigate the physical properties and survival of common non-Pseudomonas aeruginosa CF pathogens generated during coughing. We conclude that Gram-negative bacteria and Staphylococcus aureus are aerosolised during coughing, can travel up to 4 m and remain viable within droplet nuclei for up to 45 min. These results suggest that airborne person-to-person transmission is plausible for the CF pathogens we measured.


2018 ◽  
Vol 13 (4) ◽  
pp. 1934578X1801300
Author(s):  
Daniyar Sadyrbekov ◽  
Timur Saliev ◽  
Yuri Gatilov ◽  
Ivan Kulakov ◽  
Roza Seidakhmetova ◽  
...  

A cyclopropane derivative of limonene, (1 S, 4 S, 6 R)-7,7-dichloro-4-[(1 S)-2,2-dichloro-1-methylcyclopropyl]-1-methylbicyclo [4.1.0] heptane (compound 2), was synthesized and its structure was determined by NMR and X-ray crystallographic methods. In addition, an antimicrobial activity of the compound against Gram-positive ( Staphylococcus aureus, Bacillus subtilis) and Gram-negative ( Escherichia coli, Pseudomonas aeruginosa) bacterial strains was also scrutinized.


Author(s):  
Mohammad Hassan Moshafi ◽  
Ali Peymani ◽  
Alireza Foroumadi ◽  
Mohammad Reza Zabihi ◽  
Farzad Doostishoar

Introduction: Nitrofurans and nitroimidazoles are broad-spectrum antimicrobial agents, which affect the microbial DNA. The aim of the present study was to evaluate the new derivatives of these two groups of antimicrobials against certain Gram-positive and Gram-negative bacterial strains. Materials and Methods: Seven new derivatives of nitrofurans and nitroimidazoles were synthesized, and 6.4 mg of each derivative was dissolved in dimethyl sulfoxide. Then, 8 serial dilutions (0.5, 1, 2, 4, 8, 16, 32, and 64 μg/ml) of each derivative was prepared using Muller-Hinton broth, and the minimum inhibitory concentration for each derivative was measured and compared to ciprofloxacin (standard). Results: All the derivatives had no antibacterial effects against Gram-negative bacteria (minimum inhibitory concentration > 64 μg/ml); only 2-(5-nitro-2-furyl)-5-(n-pentylsulfunyl)-1,3,4-thiadiazole exhibited mild antibacterial effects against Klebsiella pneumonia (minimum inhibitory concentration of 16-32 μg/ml). The antibacterial effects of the derivatives against Gram-positive bacteria also showed variations from complete inhibition of the growth of Staphylococcus epidermidis and Bacillus subtilis (minimum inhibitory concentration < 0.5 μg/ml) by 2-(5-nitro-2-furyl)-5-(n-buthylthio)-1,3,4-thiadiazole to no inhibition of S. epidermidis and streptococcus pyogenes. Conclusion: These compounds have weak antibacterial effects; only two derivatives showed antibacterial effects similar to that of the positive control.


It is a great concern that extended-spectrum β-lactamase (ESBL) and non-ESBL uropathogenic micro-organisms have been worldwide illustrated to increase multidrug resistance. To study the prevalence and patterns of uropathogens, and antimicrobial susceptibilities profiles of ESBL and non-ESBL producing bacterial infection in a tertiary level health service center of Bangladesh. The prevalence of ESBL producing uropathogens and their antimicrobial resistance patterns were identified in 176 isolates from patients with UTI. ESBL and non-ESBL producing bacterial isolates and their antibiotic sensitivity and resistance patterns were distinguished from the 176 patients of suspected urinary tract infection. The Double-disc diffusion test was done to determine the presence of ESBL-producing bacterial strains. The most widely ESBL positive uropathogen was Escherichia coli (87%), followed by Pseudomonas aeruginosa, (6.8%), Enterococcus spp. (3.4%), Acinetobacter spp. (2.5%) and non-ESBL positive E. coli (41.4), Staphylococcus saprophyticus (25.9%), Pseudomonas aeruginosa (17.2%), Staphylococcus aureus (10.3%), and Klebsiella pneumoniae (5.2%). The current investigation found most frequently Escherichia coli in both ESBL and non-ESBL uropathogenic groups as 87% and 41.4% respectively. Generally, a large number of antibiotic resistance patterns and ESBL producing common bacterial isolates were found in this study which increases the public health problem. Therefore, for safe human life, we ought to be taking appropriate action against the threat.


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