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Molecular study of the relationship of gene expression of some genes with the temperature variation of bacterial growth




algD, Biofilm, gene expression, pela, pslA, temperature


Pseudomonas aeruginosa is an opportunistic pathogen responsible for serious infections. At least three different exopolysaccharides, alginate, polysaccharide synthesis locus (Psl), and pellicle exopolysaccharide (Pel) make up the biofilm matrix in P. aeruginosa . The effect of temperature on the biofilm formation and gene expression was examined by microtiter plate and real-time quantitative polymerase chain reaction (qRT-PCR). To be able to determine the effect of temperature on biofilm formation and gene expression of P. aeruginosa, 303 clinical and environmental samples were collected. Pseudomonas aeruginosa was isolated from 61 (20.1%) and 48 (15.8%) of the clinical and environmental samples, respectively. The ability of clinical and environmental P. aeruginosa isolates to develop biofilm was observed in 86.9% and 85.42% of the isolates, respectively, distributed into strong, moderate, and weak biofilm producers. Moreover, gene expression for pslA, pelA and algD genes was estimated for clinical and environmental isolates, the clinical P. aeruginosa isolates showed the highest biofilm production and the highest gene expression of pslA, pelA and algD genes as compared to environmental isolates when temperature changed. In summary, both clinical and environmental isolates formed biofilm and carried psl A, pel A and alg D genes regardless of the intensity of the biofilm. Also, 37°C represented the best temperature for biofilm production.


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Al-Daraghi WA, Al-Badrwi MS. Molecular Detection for Nosocomial Pseudomonas aeruginosa and its Relationship with multidrug Resistance, Isolated from Hospitals Environment. Med Legal Update. 2020 January-March; 20(1): 631-636.

Thi M, Wibowo D, Rehm B. Pseudomonas aeruginosa Biofilms. Int J Mol Sci. 2020; 21)8671): 1-25:

AL-Fridawy RA, Al-Daraghi WA, Alkhafaji MA.Isolation and Identification of Multidrug Resistance Among Clinical and Environmental Pseudomonas aeruginosa Isolates. Iraqi J Biotechnol. 2020 October;19(2): 37-45.

Ahmed IA, Aljondi IA, Alabed AA, Al-Mahdi AY, Abdsalam R. Isolation, Screening and Antibiotic Sensitivity of Pseudomonas species from Kelana Jaya Lake Soil in Selangor Malaysia. Baghdad Sci J.2021 February;18(3): 455-461.

Muhammad MH, Idris AL, Fan X, Guo Y, Yu Y, Jin X, et al .Beyond Risk: Bacterial Biofilms and Their Regulating Approaches. Front Microbiol.2020 May; 11. 928:1-20.

Skariyachan S, Sridhar VS, Packirisamy S, Kumargowda ST, Challapilli SB. Recent perspectives on the molecular basis of biofilm formation by Pseudomonas aeruginosa and approaches for treatment and biofilm dispersal. Folia Microbiol.2018; 63(4): 413–432.

Yang F, Liu G, Wenjun CJ, Ding B, Xu X. Molecular Characteristics, Antimicrobial Resistance, and Biofilm Formation of Pseudomonas aeruginosa Isolated from Patients with Aural Infections in Shanghai, China. Infect Drug Resist.2021; 14: 3637–3645.

Rocha JA, de Oliveira Barsottini M, Rocha R, Laurindo M, Laurindo de Moraes F, da Rocha S. Pseudomonas Aeruginosa: Virulence Factors and Antibiotic Resistance Genes. Braz Arch Biol Technol. 2019; 62: e19180503. .

Ghaidaa HA, Neihaya HZ, Nada ZM, Amna MA. The Biofilm Inhibitory Potential of Compound Produced from Chlamydomonas reinhardtii Against Pathogenic Microorganisms. Baghdad Sci J. 2020; 17(1): 34-41. DOI:

Ryder C, Byrd M, Wozniak DJ. Role of polysaccharides in Pseudomonas aeruginosa biofilm development. Curr Opin Microbiol. 2007; 10(6): 644–648.

Barbier M, Damron F H, María Suárez-Diez P B, Puchałka J, Albertí S, dos Santos V M et al. From the environment to the host: re-wiring of the transcriptome of Pseudomonas aeruginosa from 22 °C to 37 °C. PLoS One. 2014; 9(2): e89941.

Bisht K, Moore JL, Caprioli RM, Skaar EP, Wakeman CA. Impact of temperature-dependent phage expression on Pseudomonas aeruginosa biofilm formation. NPJ Biofilms Microbiomes. 2021; 7(22): 1-9.

Ell-Amin A, Sulieman A, El-Khalifa E. Microbiological assessment of drinking water quality in wad-medani and Khartoum states. IWTC16. 2012; 6 (4): 645-649.

Bahador N, Shoja S, Faridi F, Dozandeh-Mobarrez B, Qeshmi FI, Javadpour S, et al. Molecular detection of virulence factors and biofilm formation in Pseudomonas aeruginosa obtained from different clinical specimens in Bandar Abbas. Iran J Microbiol. 2019 February; 11 (1) : 25-30

Colvin K, Gordon V, Murakami K, Borlee B, Wozniak D, Wong G. The Pel polysaccharide can serve a structural and protective role in the biofilm matrix of Pseudomonas aeruginosa. PLoS Pathog. 2011; 7(1): e1001264.

Goldsworthy M J. Gene expression of Pseudomonas aeruginosa and MRSA within a catheter-associated urinary tract infection biofilm model. Biosci. Horiz. 2008; 1(1) :28-37.

Livak K, Schmittgen T. Analysis of relative gene expression data using real-time quantitative PCR and the -2(Delta CT) Method. Methods. 2001; 25(4): 402-408.

Statistical Analysis System, User's Guide. Statistical. Version 9.6th ed. SAS. Inst. Inc. Cary. N.C. USA.2018.

Markey B, Leonard F, Archambault M, Cullinane A, Maguire D. Clinical veterinary microbiology e-book.Elsevier Health Sciences;2013.

Gamze Yilmaz A. Development of a New <i> Pseudomonas agar Medium Containing Benzalkonium Chloride in Cetrimide Agar. Food Nutr Sci. 2017; 8(4): 367–78.

Al-Rawi D, Mahmood H M. Prevalence of Biofilm Genotype Pattern( algD −/pslD −/pelFM–) with Multidrug-Resistant in Clinical Local Pseudomonas aeruginosa Isolates Indian J Forensic Med Toxicol. 2022; 16(1): 381-391.

Dawood H, Ahmed A. Relationship between Biofilm Formation and Elastase Activity in Isolated Pseudomonas areuginosa from Iraqi Patients. Indian J Ecol. 2021; 48 (17): 388-393.

Morimatsu K, Kodai E, Daisuke H, Fumihiko T, Toshitaka U. Effects of Temperature and Nutrient Conditions on Biofilm Formation of Pseudomonas putida. Food Sci Technol Res. 2012; 18 (6): 879 – 883.

Donnarumma G, Buommino E, Fusco A, Paoletti I, Auricchio L, Tufano M. Effect Of Temperature On The Shift Of Pseudomonas Fluorescens From An Environmental Microorganism To A Potential Human Pathogen. Int J Immunopathol Pharmacol . 2010; 23( 1): 227-234

Kim S, Li X, Hwang Hj, Lee Hj. Thermoregulation of Pseudomonas aeruginosa Biofilm Formation. Appl. Environ. Microbiol. 2020 ; 86 ( 22): e01584-20.

Wu X, Al Farraj D A, Jayarajapazham R, Alkufeidy R M, Ponnuswamy V, Alkubaisi N A. Characterization of biofilm formed by multidrug resistant Pseudomonas aeruginosa DC-17 isolated from dental caries . Saudi J Biol Sci. 2020 ; 27: 2955–2960.

Alotaibi G, Bukhari M. Factors Influencing Bacterial Biofilm Formation and Development. Am J Biomed Sci. 2021; 12(6): 617-626. .

Alva PP, Sundar S, D’Souza C, Premanath R. Increased Expression of Genes Involved in Biofilm Formation in a Multidrug‑Resistant Environmental Pseudomonas aeruginosa Isolate. J Datta Meghe Inst Med Sci. 2022; 16: 357-62.

Obaid W A, Abdulwahhab A S. Impacts of starvation stress on biofilm formation and expression of virulence genes in mono-and mixed-species cultures of Pseudomonas aeruginosa and Staphylococcus aureus. Biochem Cell Arch.2021; 21(1): 685-693.

Al -Sheikhly MA, Musleh LN, Al-Mathkhury H J .Assessment of pelA-carried Pseudomonas aeruginosa isolates in respect to biofilm formation. Iraqi J Sci. 2019; 60(6): 1180–1187.