scholarly journals Prevalence of Resistance Genes to Biocides in Antibiotic-Resistant Pseudomonas Aeruginosa Clinical Isolates

2021 ◽  
Author(s):  
Farzad Khademi ◽  
Shahram Habibzadeh ◽  
Hamid Vaez ◽  
Mohsen Arzanlou ◽  
Somayeh Safarirad ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Resistance Genes ◽  
Benzalkonium Chloride ◽  
Resistance Rate ◽  
Clinical Isolates ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Chlorhexidine Digluconate ◽  
Biocide Resistance

Abstract Background: Biocides are frequently used as preservative, disinfectant and sterilizer against many microorganisms in hospitals, industry and home. However, the resistance rate of Pseudomonas aeruginosa (P. aeruginosa) strains to biocides is increasing. The aim of this study was to evaluate the antimicrobial activity of four frequently used biocides against P. aeruginosa and to determine the prevalence of genes involved in biocide resistance. Methods: A total of 76 clinical isolates of P. aeruginosa strains were used in the present study. The minimum inhibitory concentrations (MICs) of four biocides, i.e. chlorhexidine digluconate, benzalkonium chloride, triclosan and formaldehyde, against P. aeruginosa strains were determined using agar dilution method. In addition, the prevalence of biocide resistance genes was determined using the polymerase chain reaction (PCR) method.Results: In the present study, the highest MIC90 value was observed for benzalkonium chloride (MIC90=1024 μg/mL), followed by formaldehyde (MIC90=512 μg/mL), triclosan (MIC90=512 μg/mL) and chlorhexidine digluconate (MIC90=64 μg/mL). Furthermore, the prevalence of qacEΔ1, qacE, qacG, fabV, cepA and fabI genes were 73.7% (n=56), 26.3% (n=20), 11.8% (n=9), 84.2% (n=64), 81.5% (n=62) and 0% (n=0), respectively. A significant association was observed between the presence of biocide resistance genes and MICs (p<0.05). Furthermore, there was no significant association between the presence of biocide resistance genes and antibiotic resistance (p>0.05), except for levofloxacin and norfloxacin antibiotics and qacE and qacG genes (p<0.05). Conclusion: Our results revealed that chlorhexidine digluconate is the most effective biocide against P. aeruginosa isolates in Ardabil hospitals. However, we recommend continuous monitoring of the antimicrobial activity of biocides and the prevalence of biocide-associated resistance genes for a better prevention of microorganism dissemination and infection control in hospitals.

scholarly journals Characterization of Two Macrolide Resistance-Related Genes in Multidrug-Resistant Pseudomonas aeruginosa Isolates

2020 ◽  
Vol 69 (3) ◽  
pp. 349-356
Author(s):  
QING CHEN ◽  
WEI LU ◽  
DANYING ZHOU ◽  
GUOTONG ZHENG ◽  
HONGMAO LIU ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Resistance Genes ◽  
High Resistance ◽  
Critical Role ◽  
Multidrug Resistant ◽  
Macrolide Resistance ◽  
Macrolide Antibiotics ◽  
Antibiotics Resistance ◽  
Dilution Method ◽  
Agar Dilution Method

In analyzing the drug resistance phenotype and mechanism of resistance to macrolide antibiotics of clinical Pseudomonas aeruginosa isolates, the agar dilution method was used to determine the minimum inhibitory concentrations (MICs), and PCR (polymerase chain reaction) was applied to screen for macrolide antibiotics resistance genes. The macrolide antibiotics resistance genes were cloned, and their functions were identified. Of the 13 antibiotics tested, P. aeruginosa strains showed high resistance rates (ranging from 69.5–82.1%), and MIC levels (MIC90 > 256 μg/ml) to macrolide antibiotics. Of the 131 known macrolide resistance genes, only two genes, mphE and msrE, were identified in 262 clinical P. aeruginosa isolates. Four strains (1.53%, 4/262) carried both the msrE and mphE genes, and an additional three strains (1.15%, 3/262) harbored the mphE gene alone. The cloned msrE and mphE genes conferred higher resistance levels to three second-generation macrolides compared to two first-generation ones. Analysis of MsrE and MphE protein polymorphisms revealed that they are highly conserved, with only 1–3 amino acids differences between the proteins of the same type. It can be concluded that even though the strains showed high resistance levels to macrolides, known macrolide resistance genes are seldom present in clinical P. aeruginosa strains, demonstrating that a mechanism other than this warranted by the mphE and msrE genes may play a more critical role in the bacteria’s resistance to macrolides.

scholarly journals Evaluation of the Antimicrobial Activity of Some Components of the Essential Oils of Plants Used in the Traditional Medicine of the Tehuacán-Cuicatlán Valley, Puebla, México

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 295
Author(s):  
Sebastián Candelaria-Dueñas ◽  
Rocío Serrano-Parrales ◽  
Marisol Ávila-Romero ◽  
Samuel Meraz-Martínez ◽  
Julieta Orozco-Martínez ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oils ◽  
Qualitative Evaluation ◽  
Bactericidal Effect ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Diffusion Technique ◽  
Agar Dilution

In Tehuacán-Cuicatlán valley (Mexico), studies have been carried out on the essential oils of medicinal plants with antimicrobial activity and it was found that they present compounds in common such as: α-pinene, β-pinene, carvacrol, eugenol, limonene, myrcene, ocimene, cineole, methyl salicylate, farnesene, and thymol. The goal of this study was to assess the antimicrobial activity of essential oils’ compounds. The qualitative evaluation was carried out by the Kirby Baüer agar diffusion technique in Gram-positive bacteria (11 strains), Gram-negative bacteria (18 strains), and yeasts (8 strains). For the determination of the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), the agar dilution method was used. All the evaluated compounds presented antimicrobial activity. The compounds eugenol and carvacrol showed the largest inhibition zones. Regarding yeasts, the compounds ocimene, cineole, and farnesene did not show any activity. The compounds eugenol, carvacrol, and thymol presented the lowest MIC; bactericidal effect was observed at MIC level for S. aureus 75MR, E. coli 128 MR, and C albicans CUSI, for different compounds, eugenol, carvacrol, and thymol. Finally, this study shows that the essential oils of plants used by the population of Tehuacán-Cuicatlán valley share compounds and some of them have antibacterial and fungicidal activity.

scholarly journals Antimicrobial activity of honeys from two stingless honeybee species and Apis mellifera (Hymenoptera: Apidae) against pathogenic microorganisms

2014 ◽  
Vol 44 (2) ◽  
pp. 287-290 ◽  
Author(s):  
Carolinie Batista Nobre da Cruz ◽  
Fabio Alessandro Pieri ◽  
Gislene Almeida Carvalho-Zilse ◽  
Patrícia Puccinelli Orlandi ◽  
Carlos Gustavo Nunes-Silva ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Apis Mellifera ◽  
Antimicrobial Agents ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Therapeutic Approaches ◽  
E Coli ◽  
Agar Dilution ◽  
Amazonas State

Honeys are described possessing different properties including antimicrobial. Many studies have presented this activity of honeys produced by Apis mellifera bees, however studies including activities of stingless bees honeys are scarce. The aim of this study was to compare the antimicrobial activity of honeys collected in the Amazonas State from Melipona compressipes, Melipona seminigra and Apis mellifera against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Chromobacterium violaceum, and Candida albicans. Minimum inhibitory concentrations were determined using the agar dilution method with Müller-Hinton agar (for bacteria) or Saboraud agar (for yeast). Staphylococcus aureus and E. faecalis were inhibited by all honeys at concentrations below 12%, while E. coli and C. violaceum were inhibited by stingless bee honeys at concentrations between 10 and 20%. A. mellifera honey inhibited E. coli at a concentration of 7% and Candida violaceum at 0.7%. C. albicans were inhibited only with honey concentrations between 30 and 40%. All examined honey had antimicrobial activity against the tested pathogens, thus serving as potential antimicrobial agents for several therapeutic approaches.

Ginseng aqueous extract attenuates the production of virulence factors, stimulates twitching and adhesion, and eradicates biofilms of Pseudomonas aeruginosa

2011 ◽  
Vol 89 (6) ◽  
pp. 419-427 ◽  
Author(s):  
Misagh Alipour ◽  
Abdelwahab Omri ◽  
Zacharias E. Suntres
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Aqueous Extract ◽  
North American ◽  
American Ginseng ◽  
Antimicrobial Activities ◽  
Live Cells ◽  
Dilution Method ◽  
Agar Dilution Method

This study was carried out to examine the antimicrobial activity of the aqueous extract of Panax quinquefolius from North American ginseng (NAGE) root against Pseudomonas aeruginosa . The minimum inhibitory concentrations of reference and clinical isolates of Pseudomonas aeruginosa were measured by a standard agar-dilution method. At subinhibitory NAGE concentrations, the secretion of virulence factors, motility on agar, and adhesion to 96-well microplates were studied on the nonmucoid Pseudomonas aeruginosa O1 strain. At suprainhibitory concentrations, the activity of NAGE against mature biofilm complexes formed in the Calgary Biofilm Device and the Stovall flow cell were assessed. NAGE possessed an antibacterial activity against all the Pseudomonas aeruginosa strains at 1.25%–2.5% w/v. NAGE also significantly attenuated pyocyanin, pyoverdine, and lipase concentrations, stimulated twitching, and attenuated swarming and swimming motility. At 1.25% w/v, NAGE augmented adhesion, and at 5% w/v detached 1-day-old biofilms in microplates. The extract also eradicated 6-day-old mature biofilms (5% w/v), and fluorescence microscopy displayed a reduction of live cells and biofilm complexes compared with nontreated biofilms. These data suggest that the aqueous extract from North American ginseng possesses antimicrobial activities in vitro.

scholarly journals Increasing antibiotic resistance in clinical isolates of Aeromonas strains in Taiwan.

1996 ◽  
Vol 40 (5) ◽  
pp. 1260-1262 ◽  
Author(s):  
W C Ko ◽  
K W Yu ◽  
C Y Liu ◽  
C T Huang ◽  
H S Leu ◽  
...  
Keyword(s):  
United States ◽  
Antibiotic Resistance ◽  
The United States ◽  
Clinical Isolates ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Extended Spectrum ◽  
Agar Dilution

A total of 234 clinical isolates of Aeromonas, primarily A. hydrophila, were collected for the present study. Most were isolates from blood. By the agar dilution method, more than 90% of the Aeromonas strains were found to be susceptible to moxalactam, ceftazidime, cefepime, aztreonam, imipenem, amikacin, and fluoroquinolones, but they were more resistant to tetracycline, trimethoprim-sulfamethoxazole, some extended-spectrum cephalosporins, and aminoglycosides than strains from the United States and Australia.

scholarly journals Molecular and phenotypic characterization of clinical isolates belonging to a KPC-2-producing strain of ST15 Klebsiella pneumoniae from a Vietnamese pediatric hospital

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Björn Berglund ◽  
Ngoc Thi Bich Hoang ◽  
Maria Tärnberg ◽  
Ngai Kien Le ◽  
Maud Nilsson ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Klebsiella Pneumoniae ◽  
Resistance Genes ◽  
Resistance Rate ◽  
Clinical Isolates ◽  
Phenotypic Characterization ◽  
Polymorphism Analysis ◽  
Pediatric Hospital ◽  
Carbapenem Resistant ◽  
Global Epidemiology

Abstract Background Carbapenem-resistant Klebsiella pneumoniae are becoming increasingly common in hospital settings worldwide and are a source of increased morbidity, mortality and health care costs. The global epidemiology of carbapenem-resistant K. pneumoniae is characterized by different strains distributed geographically, with the strain ST258 being predominant in Europe and USA, and ST11 being most common in East Asia. ST15 is a less frequently occurring strain but has nevertheless been reported worldwide as a source of hospital outbreaks of carbapenem-resistant K. pneumoniae. Methods In this study, whole-genome sequencing and antimicrobial susceptibility testing was used to characterize 57 clinical isolates of carbapenem-resistant K. pneumoniae belonging to a strain of ST15, which were collected at a Vietnamese pediatric hospital from February throughout September 2015. Results Aside from the carbapenem resistance gene blaKPC-2, which was carried by all isolates, prevalence of resistance genes to other antibiotics including aminoglycosides, macrolides, quinolones, fosfomycin and trimethoprim, was also high. All isolates were multidrug-resistant. Susceptibility was highest to ceftazidime/avibactam (96%), gentamicin (91%) and tigecycline (82%). Notably, the colistin resistance rate was very high (42%). Single-nucleotide polymorphism analysis indicated that most isolates belonged to a single clone. Conclusions The diverse variety of antibiotic resistance genes and the high antibiotic resistance rates to last-resort antibiotics such as carbapenems and colistin, is indicative of a highly adaptable strain. This emphasizes the importance of implementation of infection controls measures, continued monitoring of antibiotic resistance and prudent use of antibiotics to prevent further selection of resistant strains and the emergence of pan-resistant clones.

scholarly journals In Vitro Activities of Garenoxacin (BMS-284756) against 170 Clinical Isolates of Nine Pasteurella Species

2002 ◽  
Vol 46 (9) ◽  
pp. 3068-3070 ◽  
Author(s):  
Ellie J. C. Goldstein ◽  
Diane M. Citron ◽  
C. Vreni Merriam ◽  
Yumi A. Warren ◽  
Kerin L. Tyrrell ◽  
...  
Keyword(s):  
Pasteurella Multocida ◽  
Active Agent ◽  
Culture Collection ◽  
Clinical Isolates ◽  
American Type Culture Collection ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Agar Dilution

ABSTRACT The in vitro susceptibilities of 170 clinical isolates plus 12 American Type Culture Collection strains of Pasteurella species comprising nine species and three Pasteurella multocida subspecies were studied by an agar dilution method. Garenoxacin (BMS-284756), a new des-fluoro(6) quinolone, was active at ≤0.06 μg/ml against all isolates, including four β-lactamase-producing strains, with >90% of the strains susceptible to ≤0.008 μg/ml. Garenoxacin was generally 1 to 2 dilutions more active than levofloxacin and moxifloxacin and was the most active agent tested. Cefoxitin required 1 μg/ml for inhibition of 51 of 182 (29%) of strains, and 3 strains (also β-lactamase producers) were resistant to doxycycline.

In vitro synergy testing of macrolide-quinolone combinations against 41 clinical isolates of Legionella.

1996 ◽  
Vol 40 (6) ◽  
pp. 1419-1421 ◽  
Author(s):  
S J Martin ◽  
S L Pendland ◽  
C Chen ◽  
P Schreckenberger ◽  
L H Danziger
Keyword(s):  
Yeast Extract ◽  
Antimicrobial Therapy ◽  
Clinical Isolates ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Agar Dilution ◽  
Legionella Species ◽  
Checkerboard Assay ◽  
Synergy Testing

Combination antimicrobial therapy against Legionella species has not been well studied. Several quinolones have activity against Legionella strains, which prompted this in vitro search for a synergistic combination with the macrolides. By a checkerboard assay, erythromycin, clarithromycin, and azithromycin, each in combination with ciprofloxacin and levofloxacin, were tested for synergy against 46 isolates of Legionella. The agar dilution method was employed using buffered charcoal-yeast extract media. A final inoculum of 10(4) CFU per spot was prepared from 24-h growth of each isolate. Plates were incubated at 35 degrees C for 48 h. Synergy, partial synergy, additive effect, or indifference was observed for all combinations of antibiotics tested. There was no antagonism observed. Synergy occurred to a significantly greater extent for the clarithromycin-levofloxacin (P = 0.0001) and azithromycin-levofloxacin (P = 0.003) combinations versus erythromycin-levofloxacin. The azithromycin-ciprofloxacin combination demonstrated significantly greater synergy than did either erythromycin-ciprofloxacin (P = 0.003) or clarithromycin-ciprofloxacin (P = 0.001). The newer macrolides clarithromycin and azithromycin may be more active in combination with a fluoroquinolone than is erythromycin.

scholarly journals In99, an In100-related integron, its occurrence and prevalence in clinical Pseudomonas aeruginosa strains from a central region of Portugal

2006 ◽  
Vol 135 (3) ◽  
pp. 502-504 ◽  
Author(s):  
T. CAETANO ◽  
S. FERREIRA ◽  
A. P. MONDEGO ◽  
A. CORREIA ◽  
S. MENDO
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Resistance Genes ◽  
Central Region ◽  
Clinical Isolates ◽  
Aminoglycoside Resistance ◽  
Class 1 Integron ◽  
Class 1 ◽  
Aminoglycoside Resistance Genes

In99, a possible ancestor of In100, is a class 1 integron associated with carbenicillinase (blaPSE) and aminoglycoside resistance genes [aac(6′)-Ib and aadA2]. In99 was present in 8 of 81 clinical isolates of Pseudomonas aeruginosa from unrelated patients collected in different years. The strains fell into two clonal groups and exhibited resistance to β-lactams and aminoglycosides.

scholarly journals In vitro minocycline activity on superinfecting microorganisms isolated from chronic periodontitis patients

2006 ◽  
Vol 20 (3) ◽  
pp. 202-206 ◽  
Author(s):  
Luciana Fernandes de Oliveira ◽  
Antonio Olavo Cardoso Jorge ◽  
Silvana Soléo Ferreira dos Santos
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Chronic Periodontitis ◽  
Periodontal Pocket ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Periodontal Pathogens ◽  
Candida Spp ◽  
Systemic Antibiotic Therapy ◽  
Staphylococcus Spp

Chronic periodontitis is the most common type of periodontitis and it is associated with various species of microorganisms. Enteric rods, Pseudomonas, Staphyloccocus and Candida have been retrieved from periodontal pockets of patients with chronic periodontitis and correlated to cases of superinfection. Local or systemic antibiotic therapy is indicated to reinforce the effects of the conventional mechanical therapy. Minocycline has been suggested as one of the most effective drugs against periodontal pathogens. The aim of this work was to evaluate the minimal inhibitory concentration (MIC) of minocycline on superinfecting microorganisms isolated from the periodontal pocket and the oral cavity of individuals with chronic periodontitis. Isolates of Enterobacteriaceae (n = 25), Staphylococcus spp. (n = 25), Pseudomonas aeruginosa (n = 9) and Candida spp. (n = 25) were included in the study. Minimal inhibitory concentrations (MIC) of minocycline were determined using the Müeller-Hinton agar dilution method. Staphylococcus spp. isolates were the most sensitive to minocycline with a MIC of 8 µg/mL, followed by Enterobacteriaceae with a MIC of 16 µg/mL. The concentration of 16 µg/mL inhibited 96% of Candida spp. isolates. The MIC for 88.8% of the isolates of Pseudomonas aeruginosa was 128 µg/mL. A concentration of 1,000 µg/mL was not enough to inhibit 100% of the tested isolates.

Sign in / Sign up

Export Citation Format

Share Document