scholarly journals Evaluation of efflux pump activity and biofilm formation in multidrug resistant clinical isolates of Pseudomonas aeruginosa isolated from a Federal Medical Center in Nigeria

Author(s):  
Florence Chijindu Ugwuanyi ◽  
Abraham Ajayi ◽  
David Ajiboye Ojo ◽  
Adeyemi Isaac Adeleye ◽  
Stella Ifeanyi Smith

Abstract Background Pseudomonas aeruginosa an opportunistic pathogen, is widely associated with nosocomial infections and exhibits resistance to multiple classes of antibiotics. The aim of this study was to determine the antibiotic resistance profile, biofilm formation and efflux pump activity of Pseudomonas strains isolated from clinical samples in Abeokuta Ogun state Nigeria. Methods Fifty suspected Pseudomonas isolates were characterized by standard biochemical tests and PCR using Pseudomonas species -specific primers. Antibiotic susceptibility testing was done by the disc diffusion method. Efflux pump activity screening was done by the ethidium bromide method and biofilm formation assay by the tissue plate method. Genes encoding biofilm formation (pslA & plsD) and efflux pump activity (mexA, mexB and oprM) were assayed by PCR. Results Thirty-nine Pseudomonas spp. were identified of which 35 were Pseudomonas aeruginosa and 4 Pseudomonas spp. All 39 (100%) Pseudomonas isolates were resistant to ceftazidime, cefuroxime and amoxicillin-clavulanate. Thirty-six (92%), 10(25.6%), 20 (51.2%), 11(28%) and 9(23%) of the isolates were resistant to nitrofurantoin, imipenem, gentamicin, cefepime and aztreonam respectively. All the isolates had the ability to form biofilm and 11 (28%) of them were strong biofilm formers. They all (100%) harboured the pslA and pslD biofilm encoding genes. Varied relationships between biofilm formation and resistance to ciprofloxacin, ofloxacin, cefixime, gentamicin, imipenem, and aztreonam were observed. Only 23(59%) of the Pseudomonas isolates phenotypically exhibited efflux pump activity but mexA gene was detected in all 39 (100%) isolates while mexB and oprM genes were detected in 91%, 92%, and 88% of strong, moderate and weak biofilm formers respectively. Conclusion Multidrug resistance, biofilm and efflux pump capabilities in Pseudomonas aeruginosa have serious public health implications in the management of infections caused by this organism.

2021 ◽  
Vol 12 (3) ◽  
pp. 1-5
Author(s):  
Tarek El-Said El-Banna ◽  
Fatma Ibrahim Sonbol ◽  
Heba M El-Dawy ◽  
Lamiaa A Al-Madboly

Nosocomial and community acquired infections that caused by multidrug-resistant (MDR) Klebsiella pneumoniae isolates are widespread recently resulting in high morbidity and mortality due to limited number of treatment options with effective antibiotics. The aim of this study is to evaluate the antibiotic resistance profile, biofilm formation and efflux pump activity of MDR K. pneumoniae isolates collected from different hospitals in Tanta, Egypt. A total of 70 K. pneumoniae isolates characterized by standard biochemical tests and confirmed by MALDI-TOF/MS were screened for antibiotic susceptibility, efflux pump activity and biofilm formation. Isolates displayed high resistance to penicillins, cephalosporins, trimethoprim-sulfamethoxazole and the majority of tested fluoro/-quinolones and decreased resistance to imipenem, amikacin, chloramphenicol, tigecycline and colistin. Out of 70 K. pneumoniae isolates, 2 isolates exhibited Pan Drug-Resistance (PDR) profile while 57 (81.4%) and 11 (15.7%) exhibited MDR and Extensively drug-resistance (XDR) profiles, respectively. Sixty-four (91.4%) isolates exhibited efflux pump activity while all tested isolates had the ability to form biofilm with varied degrees as 40 (57.1%), 26 (37.1%), and 4 (5.7%) isolates were strong, moderate and weak biofilm producers, respectively. Also, a strong relation between efflux pump activity and biofilm formation per isolate was detected. In conclusion, Multidrug resistance, biofilm formation and efflux pump capabilities in K. pneumoniae have serious public health implications in the management and control of infections caused by this bacterium. Therefore, a multifaceted approach and precise planning are recommended in controlling these infections


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Elizabeth Tolulope Olubisose ◽  
Abraham Ajayi ◽  
Adeyemi Isaac Adeleye ◽  
Stella Ifeanyi Smith

Abstract Background Multidrug resistance efflux pumps and biofilm formation are mechanisms by which bacteria can evade the actions of many antimicrobials. Antibiotic resistant non-typhoidal Salmonella serovars have become wide spread causing infections that result in high morbidity and mortality globally. The aim of this study was to evaluate the efflux pump activity and biofilm forming capability of multidrug resistant non-typhoidal Salmonella (NTS) serovars isolated from food handlers and animals (cattle, chicken and sheep) in Lagos. Methods Forty eight NTS serovars were subjected to antibiotic susceptibility testing by the disc diffusion method and phenotypic characterization of biofilm formation was done by tissue culture plate method. Phenotypic evaluation of efflux pump activity was done by the ethidium bromide cartwheel method and genes encoding biofilm formation and efflux pump activity were determined by PCR. Results All 48 Salmonella isolates displayed resistance to one or more classes of test antibiotics with 100% resistance to amoxicillin-clavulanic acid. Phenotypically, 28 (58.3%) of the isolates exhibited efflux pump activity. However, genotypically, 7 (14.6%) of the isolates harboured acrA, acrB and tolC, 8 (16.7%) harboured acrA, acrD and tolC while 33 (68.8%) possessed acrA, acrB, acrD and tolC. All (100%) the isolates phenotypically had the ability to form biofilm with 23 (47.9%), 24 (50.0%), 1 (2.1%) categorized as strong (SBF), moderate (MBF) and weak (WBF) biofilm formers respectively but csgA gene was detected in only 23 (47.9%) of them. Antibiotic resistance frequency was significant (p < 0.05) in SBF and MBF and efflux pump activity was detected in 6, 21, and 1 SBF, MBF and WBF respectively. Conclusion These data suggest that Salmonella serovars isolated from different food animals and humans possess active efflux pumps and biofilm forming potential which has an interplay in antibiotic resistance. There is need for prudent use of antibiotics in veterinary medicine and scrupulous hygiene practice to prevent the transmission of multidrug resistant Salmonella species within the food chain.


Author(s):  
Rustini Rustini ◽  
Jamsari Jamsari ◽  
Marlina Marlina ◽  
Nasrul Zubir ◽  
Yori Yuliandra

Objectives: Pseudomonas aeruginosa is an opportunistic pathogen that has an innate resistance to some antibiotics. This bacterium is one of the mostcommon causes of nosocomial infections that include surgical wound infections, burns, and urinary tract infections. The bacteria have been reportedlyresistant to many antibiotics and have developed multidrug resistance (MDR). The objective of the study was to determine the resistance pattern ofP. aeruginosa isolated from clinical samples of patients against some major antibiotics.Methods: Isolates of P. aeruginosa were obtained from clinical sample of urine, sputum, swabs, pus, feces, and blood and cultured in cetrimide agar. P.aeruginosa ATCC 27853 was used as a positive control. The antibacterial susceptibility testing was conducted against 13 antibiotics: Ceftazidime, cefotaxime,ceftriaxone, cefoperazone, ciprofloxacin, levofloxacin, ofloxacin, gentamicin, amikacin, piperacillin, ticarcillin, meropenem, and imipenem. The examinationwas carried out using agar diffusion method of Kirby-Bauer and following the standards from Clinical and Laboratory Standards Institute (CLSI).Results: The results showed that bacterial resistance was established against all tested antibiotics. The highest number of resistance was shownagainst ceftriaxone (44.21%), whereas the most susceptibility was exhibited against amikacin (only 9.47% of resistance). MDR P. aeruginosa (MDRPA)was detected on almost all clinical samples tested, except the feces. The sample with the highest percentage of MDRPA was the pus.Conclusion: The study concludes that the most effective antibiotic against P. aeruginosa is amikacin (91.51%), whereas the most resistance is exhibited to ceftriaxone (43.16%).


2020 ◽  
pp. 59-67
Author(s):  
Sulaiman D. Sulaiman ◽  
Ghusoon A. Abdulhasan

  Pseudomonas aeruginosa is considered as a developing opportunistic nosocomial pathogen and is well-known for its multidrug resistance that can be efficiently treated by a combination of antibiotics andefflux pump inhibitors (EPI). Therefore, the purpose of this study was to investigate the effect of curcumin as an EPI for the enhancement of the effectiveness of antibiotics against multidrug resistant (MDR) isolates ofP. aeruginosa. Susceptibility patterns of suspected bacteria was determined using the disc diffusion method andresistant bacteria were identified using chromogenic agar and 16S rDNA. The effectsof curcuminon the enhancement of antibiotics’s activity was evaluated usingthe broth microdilution method.The susceptibility patterns for 50 (67.6%) suspectedP. aeruginosaisolates showed that 36 (72%) of these isolateswere resistant to one of the used antibiotics,whereasonly 21 (42%) were MDR. The highest percentage of resistance was observedtoceftazidime (66%) followed by ciprofloxacin and levofloxacin (40%). Only 35 isolates were specified by chromogenic agar and 16S rDNAas P. aeruginosa.The minimal inhibitory concentration (MIC) of 35 isolates for ciprofloxacin resistant was between 4 and128 µg/ml while for ceftazidime was between 64and 512 µg/ml. After the addition of 50 μg/ml curcumin with ciprofloxacin, there wasa significant increase in the sensitivity (p≤ 0.01) of 13 MDR P.aeroginosa isolates whereas no differences in the sensitivity to ceftazidime were recorded before and after addition ofcurcumin. In conclusion, the results of this study show that curcumin can decrease the MIC value of ciprofloxacin in MDR isolates of P. aeruginosaand can be used as a native compound to enhance the treatment of resistant isolates with ciprofloxacin.


Author(s):  
Fateme DAVARZANI ◽  
Navid SAIDI ◽  
Saeed BESHARATI ◽  
Horieh SADERI ◽  
Iraj RASOOLI ◽  
...  

Background: Pseudomonas aeruginosa is one of the most common opportunistic bacteria causing nosocomial infections, which has significant resistance to antimicrobial agents. This bacterium is a biofilm and alginate producer. Biofilm increases the bacterial resistance to antibiotics and the immune system. Therefore, the present study was conducted to investigate the biofilm formation, alginate production and antimicrobial resistance patterns in the clinical isolates of P. aeruginosa. Methods: One hundred isolates of P. aeruginosa were collected during the study period (from Dec 2017 to Jul 2018) from different clinical samples of the patients admitted to Milad and Pars Hospitals at Tehran, Iran. Isolates were identified and confirmed by phenotypic and genotypic methods. Antimicrobial susceptibility was specified by the disk diffusion method. Biofilm formation and alginate production were measured by microtiter plate and carbazole assay, respectively. Results: Sixteen isolates were resistant to all the 12 studied antibiotics. Moreover, 31 isolates were MultidrugResistant (MDR). The highest resistance rate was related to ofloxacin (36 isolates) and the least resistance was related to piperacillin-tazobactam (21 isolates). All the isolates could produce the biofilm and alginate. The number of isolates producing strong, medium and weak biofilms was equal to 34, 52, and 14, respectively. Alginate production was more than 400 μg/ml in 39 isolates, 250-400 μg/ml in 51 isolates and less than 250 μg/ml in 10 isolates. Conclusion: High prevalence of MDR, biofilm formation, and alginate production were observed among the clinical isolates of P. aeruginosa. The results also showed a significant relationship between the amount of alginate production and the level of biofilm formation.


Author(s):  
Pakhshan A. Hassan ◽  
Adel K. Khider

Acinetobacter baumannii is an opportunistic pathogen that is reported as a major cause of nosocomial infections. The aim of this study was to investigate the biofilm formation by A. baumannii clinical and soil isolates, to display their susceptibility to 11 antibiotics and to study a possible relationship between formation of biofilm and multidrug resistance. During 8 months period, from June 2016 to January 2017, a total of 52 clinical and 22 soil isolates of A. baumannii were collected and identified through conventional phenotypic, chromo agar, biochemical tests, API 20E system, and confirmed genotypically by PCR for blaOXA-51-like gene. Antibiotic susceptibility of isolates was determined by standard disk diffusion method according to Clinical and Laboratory Standard Institute. The biofilm formation was studied using Congo red agar, test tube, and microtiter plate methods. The clinical isolates were 100% resistance to ciprofloxacin, ceftazidime, piperacillin, 96.15% to gentamicin, 96.15% to imipenem, 92.31% to meropenem, and 78.85% to amikacin. The soil A. baumannii isolates were 100% sensitive to imipenem, meropenem, and gentamicin, and 90.1% to ciprofloxacin. All A. baumannii isolates (clinical and soil) were susceptible to polymyxin B. The percentage of biofilm formation in Congo red agar, test tube, and microtiter plate assays was 10.81%, 63.51%, and 86.48%, respectively. More robust biofilm former population was mainly among non-MDR isolates. Isolates with a higher level of resistance tended to form weaker biofilms. The soil isolates exhibited less resistance to antibiotics than clinical isolates. However, the soil isolates produce stronger biofilms than clinical isolates.


2019 ◽  
Vol 21 (2) ◽  
pp. 110-116
Author(s):  
Rajani Shrestha ◽  
N. Nayak ◽  
D.R. Bhatta ◽  
D. Hamal ◽  
S.H. Subramanya ◽  
...  

Clinical isolates of Pseudomonas aeruginosa often exhibit multidrug resistance due to their inherent ability to form biofilms. Drug resistance in Ps. aeruginosa is a major clinical problem, especially in the management of patients with nosocomial infections and those admitted to ICUs with indwelling medical devices. To evaluate the biofilm forming abilities of the clinical isolates of Ps. aeruginosa and to correlate biofilm formation with antibiotic resistance. A total of 90 consecutive isolates of Ps. aeruginosa obtained from various specimens collected from patients visiting the Manipal Teaching Hospital, Pokhara, Nepal between January 2018 - October 2018 were studied. Isolates were identified by standard microbiological methods. Antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion method. All the isolates were tested for their biofilm forming abilities by employing the tissue culture plate assay. Of the 90 Ps. aeruginosa isolates, maximum i.e 42 (46.6%) were from patients in the age group of > 50 years. Majority (30; 33.3%) of the isolates were obtained from sputum samples. However, percentage isolation from other specimens like urine, endotracheal tube (ETT), pus, eye specimens and blood were 18.9%, 16.7%, 16.7%, 7.8% and 6.7% respectively. All the isolates were sensitive to polymixin B and colistin, 91.1% of the organisms were sensitive to imipenem, and more than 80% to aminoglycosides (80% to gentamicin, 83.3% to amikacin). A total of 29 (32.2%) organisms were biofilm producers. Maximum numbers of biofilm producing strains were obtained from ETT (8 of 15; 53.3%), pus (8 of 15; 53.3%) and blood (2 of 6; 33.3%) i.e from all invasive sites. None of the isolates from noninvasive specimens such as conjunctival swabs were biofilm positive. Significantly higher numbers of biofilm producers (23 of 29; 79.3%) were found to be multidrug resistant as compared to non-biofilm (6 of 61; 9.8%) producers (p=0.000). Ps. aeruginosa colonization leading to biofilm formation in deep seated tissues and on indwelling devices is a therapeutic challenge as majority of the isolates would be recalcitrant to commonly used antipseudomonal drugs. Effective monitoring of drug resistance patterns in all Pseudomonas clinical isolates should be a prerequisite for successful patient management.


2021 ◽  
Vol 12 ◽  
Author(s):  
Dejing Shang ◽  
Xue Han ◽  
Wanying Du ◽  
Zhiru Kou ◽  
Fengquan Jiang

Pseudomonas aeruginosa uses quorum sensing (QS) to control virulence, biofilm formation and antibiotic efflux pump expression. The development of effective small molecules targeting the QS system and biofilm formation represents a novel attractive strategy. In this present study, the effects of a series of Trp-containing peptides on the QS-regulated virulence and biofilm development of multidrug-resistant P. aeruginosa, as well as their synergistic antibacterial activity with three classes of traditional chemical antibiotics were investigated. The results showed that Trp-containing peptides at low concentrations reduced the production of QS-regulated virulence factors by downregulating the gene expression of both the las and rhl systems in the strain MRPA0108. Biofilm formation was inhibited in a concentration-dependent manner, which was associated with extracellular polysaccharide production inhibition by downregulating pelA, algD, and pslA transcription. These changes correlated with alterations in the extracellular production of pseudomonal virulence factors and swarming motility. In addition, the combination of Trp-containing peptides at low concentration with the antibiotics ceftazidime and piperacillin provided synergistic effects. Notably, L11W and L12W showed the highest synergy with ceftazidime and piperacillin. A mechanistic study demonstrated that the Trp-containing peptides, especially L12W, significantly decreased β-lactamase activity and expression of efflux pump genes OprM, MexX, and MexA, resulting in a reduction in antibiotic efflux from MRPA0108 cells and thus increasing the antibacterial activity of these antibiotics against MRPA0108.


2020 ◽  
Vol 18 ◽  
Author(s):  
Sepideh Hassanzadeh ◽  
Sudabeh Ebrahimi ◽  
Sara Ganjloo ◽  
Saeid Amel Jamehdar ◽  
Samaneh Dolatabadi

Introduction: The biofilm formation by Pseudomonas aeruginosa seems to protect the bacteria from antibiotics since these entities are highly resistant to such antimicrobial agents. The aim of this study was to investigate the role of Lactobacillus salivarus, Lactobacillus plantarum supernatants and CuII Schiff base complex in eliminating planktonic cells and biofilm of P. aeruginosa. Methods: : One hundred specimens of blood, urine, cerebrospinal fluid, respiratory samples, and wound swabs were collected from patients attending three hospitals in Mashhad. All specimens were identified by biochemical tests. The susceptibility of the isolates to the conventional antibiotics were assessed using disk diffusion method. The biofilm formation ability of P. aeruginosa isolates was evaluated by crystal violet assay and confirmed using PCR. The anti-planktonic and anti-biofilm ability of L. salivarus, L. plantarum supernatants and CuII Schiff base complex was evaluated separately in P. aeruginosa isolates. Results and Conclusion: The highest and lowest resistance rates was detected in Cefazoline (95%) and cefepime (23%), respectively. The thickest biofilm was produced by 8% of P. aeruginosa isolates, 9% and 83% of the isolates were considered as moderate and weak biofilm producers, respectively. The rhlR and lasR genes was reported in 100% of the isolates, but algD gene was existence in 92% of them. Particularly, the CuII Schiff base complex could affect both planktonic and biofilm cells by the lowest concentration in comparison of probiotic supernatants. L. plantarum supernatant inhibited planktonic cells at a lower concentration than L. salivarius. Also, L. salivarius showed better antibiofilm activity than another probiotic in lower doses of supernatant. Unlike that these compounds have not completely eliminated biofilm cells, but only reduced the biofilm formation.Metal Schiff base complex and Lactobacillus supernatants is a potent antimicrobial agent against Pseudomonas aeruginosa biofilm cells.


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