Investigating the antimicrobial and antibiofilm effects of clove extract on clinical isolates of Pseudomonas aeruginosa in Kashan

BACKGROUND AND ABJECTIVEPseudomonas aeruginosa bacteria is one of the main causes of nosocomial infections, which is considered as important public health challenges. Pseudomonas aeruginosa causes infections in different parts of the body such as the respiratory tract, urinary tract, and digestive tract. These infections include bacteremia, septicemia, pneumonia, skin infections and wounds, etc. The spread of drug-resistant Pseudomonas aeruginosa, especially to multi drugs resistant (MDR), has led to an increase in complications and death caused by infections of this pathogen. One of the main reasons for resistant bacteria is the formation of biofilm, which increases their resistance to most classes until its resistance is ۱۰۰ times the initial resistance.MATERIALS AND METHODSIn this cross-sectional-descriptive study, all of ۴۰ isolates of Pseudomonas aeruginosa was isolated from different clinical specimen (blood, wound, cerebrospinal fluid (CSF), urine, sputum, bronchoalveolar lavage, synovial fluid, pleural fluid, etc.). The bacteria isolates to surgery, intensive care unit (ICU), critical care unit (CCU), pediatrics, internal medicine, emergency, obstetrics and gynecology, otolaryngology and outpatient departments of Shahid Beheshti Hospital in Kashan were collected. Primary identification based on oxidase, catalase, triple sugar iron, fermentation of various sugars, citrate test, indole, VP, MR, growth at ۴۲ degrees Celsius, color, production of pigments, investigation of movement on SIM environment and specific smell were done. Then Polymerase chain reaction (PCR) as molecular method using oprL gene was used for final confirmation. Then, isolates of Pseudomonas aeruginosa producing biofilm were identified by microtiter plate assay. Finally, the antibacterial and anti-biofilm effect of clove extract was investigated in these bacteria.RESULTS AND DISCUSSIONThe size of the band observed in PCR was ۱۹۳ base pair, which was the molecular confirmation of Pseudomonas aeruginosa bacteria. In this study, ۲۳ isolates (۵۷.۵) that have the ability to form a strong biofilm, ۱۰ moderate isolates (۲۶%) and ۷ weak isolates (۱۶.۵%). The most bacteria isolated able to produce strong biofilm were from the ICU department (۲۳.۸%). The minimum inhibitory concentration (MIC۱۰۰) of clove extract is ۶۲.۵-۱۲۵ mg/ml and the۲۱۲minimum biofilm inhibitory concentration (MBIC۱۰۰) was ۳۱.۲۵-۶۲.۵ mg/ml. Our results demonstrate that MDR Pseudomonas aeruginosa are produce more biofilm. Altered changes in quantity of biofilm formation were detected to be affected clinical isolates with sub-MIC concentrations of clove extract. Today, the main strategy to control and eradicate resistant bacteria producing biofilm is to use chemical biocides and disinfectant solutions, which have many unwanted side effects. Also, common uses are limited due to increased drug resistance. The use of new antimicrobial agents such as herbal plants with less side effects its can help us. One of these plant extracts is clove extract, which was observed in this study to its have inhibited growth of Pseudomonas aeruginosa bacteria. In addition, it’s prevented the formation of biofilm.CONCLUSIONUsing natural extracts instead of chemicals can be helpful in controlling drug-resistant bacteria, especially MDR. It is suggested to investigate the antimicrobial activity of clove extract on other antibiotic-resistant bacteria such as Staphylococcus aureus, Enterococcus, and Escherichia coli.

کلیدواژه ها:

Pseudomonas aeruginosa ، biofilm ، antimicrobial activity ، clove extract.