Strong Biofilm Producers Research Articles

Antibiotic Resistance, Biofilm Formation, and Identification of FimH and FimA Adhesion Genes in Uropathogenic Escherichia Coli (UPEC) Isolated from Patients in Baghdad Province

Urinary tract infections (UTIs) are one of the most common infectious disorders worldwide. The most frequent cause of UTIs is uropathogenic Escherichia coli (UPEC). The current study is designed to assess the resistance of antibiotics, the formation of biofilm, and the detection of adhesion genes in E. coli isolated from patients with UTIs. A hundred and fifty samples were collected from patients with confirmed UTIs in Baghdad province during the period of October 2022 to February 2023. Isolation and identification of E. coli were performed using cultural characteristics, gram staining, and biochemical examination, and the results indicated that 52 (35%) isolates were identified as E. coli. Eleven antibiotic discs were utilized to estimate the sensitivity of E. coli isolates. 98% of isolates were resistant to ampicillin, followed by 75.5% of isolates resistant to both trimethoprim/sulfamethoxazole and fosfomycin, followed by 73.5, 71.4, 67.3, 53.1, and 6.1% of isolates resistant to imipenem, ceftazidime, nitrofurantoin, cefepime, and amikacin. All isolates were sensitive to piperacillin-tazobactam, ciprofloxacin, and aztreonam at 100%, 100%, and 98%, respectively. The microtiter plate method was utilized to estimate the ability of E. coli to form biofilm. The majority of isolates (69.2%; n = 36) were moderate biofilm producers, while 19.2% (n = 10) and 11.5% (n = 6) of isolates were strong and weak biofilm producers, respectively. Polymerase Chain Reactions (PCR) were applied to determine the gene expression level of adhesion genes (fimH and fimA genes). Forty isolates harbored both fimH and fimA genes.

Critical resistance to carbapenem and aminoglycosides in Pseudomonas aeruginosa: spread of blaNDM/16S methylase armA harboring isolates with intrinsic resistance mechanisms in Kerman, Iran

BackgroundCarbapenem-resistant Pseudomonas aeruginosa (CRPA) is one of the main Gram-negative bacterium causes of infections in hospital settings, and the spread of them is a significant challenge to public health.MethodsA total of 30 non-duplicate isolates of CRPA were collected. Antibacterial susceptibility of isolates to antibiotic agents, AmpC β-lactamase production, and biofilm formation were determined. Minimum biofilm inhibitory concentrations (MBIC) of isolates to cefepime (FEP), imipenem (IPM), ceftazidime (CAZ), and meropenem (MEM) were evaluated with/without cloxacillin (CLX). The carbapenemase and 16 S rRNA methylase genes were identified by PCR, and the transcription levels of oprD, ampC, and mexA genes were determined by quantitative real-time PCR (qPCR). ERIC-PCR was used to detect genetic relationships among isolates.ResultsAll isolates were multidrug resistant (MDR) and strong biofilm producers. The resistance genes including blaNDM, blaIMP, blaVIM, blaSIM, blaGES, and armA were detected in 21 (70%), 6 (20%), 3 (10%), 2 (6.6%), 1 (3.3%), and 17 (56.6%) of the isolates, respectively. CLX at 500 and 1000 µg/mL significantly reduced the level of MIC to MEM, IPM, CAZ, and FEP, also at 2000 µg/mL significantly reduced the level of MBIC to MEM, IPM, CAZ, and FEP. In all isolates, the transcription levels of oprD were significantly downregulated as well as significantly increased for ampC and mexA. ERIC-PCR typing results divided 30 isolates into four clusters A to D.ConclusionIn this study, we reported the spread of different clones of CRPA harboring co-existence of various carbapenemase genes with armA 16 S rRNA methylase for the first time in Kerman, Iran. Also, our isolates had several mechanisms of resistance to carbapenems as well as ability biofilm formation along with resistance to aminoglycosides, the further spread of which could cause serious challenges in our hospital settings. Therefore, serious monitoring is necessary to reduce their prevalence.

Quinolone and Tetracycline-Resistant Biofilm-Forming Escherichia coli Isolates from Slovak Broiler Chicken Farms and Chicken Meat

Escherichia coli isolates from intensive poultry production are associated with antimicrobial resistance and worldwide health problems. The aim of the study was to detect and evaluate the phenotypic and genotypic antimicrobial resistance, biofilm formation, phylogenetic typing, and virulence factors in E. coli isolates from the rectal swabs of chickens from two farms and swabs of chicken meat purchased from Slovakian food markets. Interpretative readings of minimal inhibitory concentration (MIC) revealed dominant resistance to ampicillin (>50%) in both groups. We also detected higher resistance to ciprofloxacin (45%), tetracycline, ampicillin + sulbactam, and trimethoprim + sulfonamide (each >30%). Here, 28.57% of the strains studied were multidrug-resistant (MDR). The formation of weak biofilms was confirmed in 8.8% of E. coli, while one of the strains obtained from chicken cloacal swabs was classified as a strong biofilm producer. The most frequently confirmed phylogenetic groups in E. coli were B1 and A1 in all groups. PCR detection revealed the presence of genes encoding tetracycline resistance (tetAB) and plasmid-mediated quinolone resistance (qnrABS), and Int1 (52.9%), Tn3 (76.5%), kpsMT II (8.8%), fimA (97.1%), cvaC (38.2%), and iutA (76.5%) genes in the strains studied. Our results demonstrate that chickens and chicken meat were the source of antibiotic-resistant, biofilm-forming, and virulent E. coli, representing a potential risk from the point of view of the One Health concept.

2,4-Di-Tert-Butylphenol of Streptomyces luridiscabiei MMS-10 Inhibits Biofilm Forming Cariogenic Streptococcus mutans ULSP-2.

Dental caries is a common chronic infectious disease of the oral cavity that affects the overall oral health of the individual. Cariogenic bacteria have long been recognized for their role in developing chronic dental infections. Drug-resistant bacteria represent a global challenge to effective pathogen control in caries. The present study aimed to isolate and identify soil actinomycetes for their antibacterial and anti-biofilm activities against antibiotic-resistant and biofilm-forming cariogenic bacteria. Thirteen caries bacteria isolated from infected tooth samples were evaluated for antibiotic resistance and biofilm formation. The isolate ULSP-2 showed the highest antibiotic resistance score (0.714) and was found to be a strong biofilm producer when tested by congo red agar and microtiter plate assays. The bacterium was identified as Streptococcus mutans based on morphological, biochemical, and molecular characterization. The effect of ethyl acetate extracts from 20 soil actinomycetes on the growth and biofilm formation ability of S. mutans was evaluated. The MMS-10 extract strongly inhibited growth (18.5 ± 0.5mm) and biofilm formation (56.46 ± 0.32%) of S. mutans at 100µg/mL. The isolate MMS-10 was identified at the molecular level as Streptomyces luridiscabiei. Based on FTIR, NMR, and GC-MS analysis, the purified MMS-10 extract was characterized and identified as 2,4-Di-tert-butylphenol. The metabolite's physiological, physicochemical, and pharmacokinetic properties were analyzed using the Swiss ADME web server and found to satisfy the criteria of drug-likenessof a molecule. The study revealed the significance of soil actinomycetes in controlling growth and biofilm formation in cariogenic S. mutans.

ISOLATION AND CHARACTERIZATION OF BIOFILM FORMING ESCHERICHIA COLI FROM CHICKEN MEAT SAMPLES

The present study was aimed to investigate the presence of Escherichia coli (E.coli) in raw chicken meat samples collected from retail shops, as well as the biofilm-forming ability of field isolates, and to characterize different adhesion genes. Out of 20 chicken meat samples, 17 (85%) were positive for E. coli. Fifteen E. coli strains were characterized by PCR using the 16S rDNA primers and all the isolates were positive which confirmed that all the isolates were E.coli. Out of the 15 confirmed E.coli field isolates which were subjected to biofilm-forming assay, 46% of them were found to be strong biofilm producers. While all the isolates were screened for the presence of adhesion genes viz. luxS, csgA, fimH, fimA, and papC, the adhesion gene luxS was detected in all the strains (100%). The other adhesion genes csgA, fimH and fimA were detected in 93%, 93%, and 73% of the isolates, respectively. The E. coli field isolates were screened blaTEM gene was detected in only four strains, which was categorized under strong biofilm producers. This study demonstrated the presence of biofilm forming E. coli in the raw chicken meat samples as contaminants, causing spoilage and potentially posing risk to consumer’s health and safety.

Antifungal susceptibility and biofilm production of Candida species- causative agents of female genital tract infections.

Recurrent vulvovaginal candidosis (RVVC) is a chronic infection affecting 8-10% of women worldwide. Biofilm production of the infecting species and reduced sensitivity to antimycotics could contribute to the recurrence of this infection. This study aimed to examine the biofilm production ability and antifungal susceptibility of genital yeast isolates to determine their virulence potential. Matrix-assisted laser desorption in ionization-time of flight mass spectrometry (MALDI-TOF MS) was used to identify 300 Candida species. Using crystal violet method, strains were categorized into non-producers, weak, moderate, and strong biofilm producers (BFP). Antifungal susceptibility testing was performed using commercial Integral System YEASTS Plus test (ISYPT) and broth microdilution method (BMM). MALDI-TOF MS identified 150 Candida albicans, 124 non-albicans Candida (NAC), and 26 Saccharomyces cerevisiae strains. Within 138 (46.0%) BFP, 23 (16.7%) were strong, 44 (31.9%) moderate, and 71 (51.4%) weak. BMM was done for 43 BFP selected isolates with nystatin MIC ˃1.25 μl, fluconazole MIC ˃64 μl, and clotrimazole MIC ˃1.0 μl determined by ISYPT. Compared to all examined isolates, BMM confirmed that: i) C. albicans and NAC BFP showed low sensitivity to fluconazole (12% and 4%, respectively); ii) all BFP showed low sensitivity to nystatin (12.7% C. albicans, 14.5% NAC, and 23.1% S. cerevisiae); iii) clotrimazole in vitro was the most efficient regarding C. albicans and S. cerevisiae strains, but in 4.0% NAC BFP for this antimycotic higher MIC was established. Novel antimycotics or possible combinations of antifungal agents and natural products could be a new treatment option for RVVC.

Antimicrobial Efficacy of Quercetin against Biofilm Production by <i>Staphylococcus Aureus</i>

Background: The bad administration of antibiotics represents a worldwide health issue as it leads to the emergence of multidrug-resistant microbes including Staphylococcus aureus, which represents a significant challenge for public health since it increases its ability to cause potentially fatal infections. Objective: This study aims to reduce the bacterium’s ability to form biofilms and antibiotic resistance. Methods: Thirty Staphylococcus aureus isolates were isolated from different clinical samples in Baghdad city and their ability to form biofilm was tested using the Microtiter Plate method. Out of 30 isolates, eight strong biofilm producer isolates were further investigated for their antimicrobial activity and biofilm formation with the impact of quercetin. Results: The results showed the ability of quercetin to inhibit bacteria and had an antibiofilm activity that was determined through investigation of the minimal inhibitory concentration by taking different concentrations. The anti-biofilm activity of quercetin was determined for the eight isolates and the results showed that biofilm formation was reduced by 100% using quercetin at a concentration of 3.1 mg/ml. Conclusions: Quercetin represents a suitable alternative to synthetic antimicrobials with the increased rate of drug-resistant bacteria among clinical samples with highly effective ability as anti-biofilm formation among strong biofilm producers of S. aureus.

Biofilm Production Activity and Antibiotics Susceptibility of Streptococcus mutans Isolates from Patients with Dental Caries

Dental caries, a prevalent chronic infectious ailment, commences with the adherence of cariogenic bacteria to the teeth, particularly Streptococcus mutans. These microorganisms utilize sugars to produce acid, resulting in the gradual demineralization of the dental structure. Streptococcus mutans a gram positive bacterium is found to play the most significant role in the dental caries in terms of being the earliest colonizer in the formation of caries. The current research focuses on the isolation and identification of the Streptococcus mutans pathogen in individuals affected by dental caries. The isolated strains were cultured on specific media, with one hundred samples of dental caries obtained from human teeth. Among these samples, fifty were identified as positive bacterial isolates utilizing MS-agar (Mitist Salivares agar), with ten isolates categorized under the group Streptococci and twenty isolates identified as S. mutans. Identification of bacterial isolates was carried out based on morphological and cultural characteristics, biochemical tests, and VITEK-II. Additionally, an antibiogram assay was conducted to assess the susceptibility and resistance of the pathogen to various drugs. The findings revealed that all locally isolated S. mutans strains displayed 100% resistance to Cefepime, while showing different levels of resistance and susceptibility to other antibiotics such as Doxycycline, Amoxicillin-clavulanic acid, Trimethoprim-sulfamethoxazole, Vancomycin, Tetracycline, Ampicillin, and Meropenem. In this study, ELISA was employed to differentiate between Streptococcus. mutans isolates that produced biofilms and those that did not by utilizing the optical density at 630 nm. Bacterial biofilms contribute to chronic diseases that pose challenges in treatment. Twenty distinct isolates were evaluated for their biofilm-forming capabilities, with 9 (45%) identified as strong biofilm producers, 7 (35%) classified as moderate biofilm producers, and 4 (20%) categorized as weak biofilm producers

Associations between biofilm formation and virulence factors among clinical Helicobacter pylori isolates

IntroductionHelicobacter pylori (H. pylori) causes several gastrointestinal diseases. Its virulence factors contributing to disease development include biofilm formation, cytotoxin-associated gene A (CagA) and vacuolating cytotoxin A (VacA) proteins that induce host tissue damage. In addition, urease activity enables H. pylori growth in the gastric acidic environment. This work aimed to characterize bacterial factors associated with biofilm production among 89 clinical H. pylori isolates, collected from patient gastric biopsies. MethodsBiofilm production was detected using the crystal violet method. PCR was performed to determine vacA genotype (s1m1, s1m2, s2m1 and s2m2) and cagA gene presence. Urease activity was measured via the phenol red method. Susceptibility to six antibiotics was assessed by the Etest method. ResultsMost H. pylori isolates produced biofilm. No association was found between biofilm-formation capacity and cagA presence or vacA genotype. Urease activity levels varied across isolates; no association was found between biofilm-formation and urease activity. Clarithromycin resistance was measured in 49 % of the isolates. Isolates susceptible to tetracycline were more commonly strong biofilm producers. In contrast, a significantly higher rate of strong biofilm producers was observed among resistant isolates to amoxicillin, levofloxacin and rifampicin, compared to susceptible isolates. Non-biofilm producers were more common among isolates sensitive to rifampicin and metronidazole, compared to resistant isolates. ConclusionsFurther studies are needed to understand the factors that regulate biofilm production in order to search for treatments for H. pylori biofilm destruction.

Association of antibiotic resistance and biofilm formation in Escherichia coli ST131/O25b.

Urinary tract infections are becoming difficult to treat every year due to antibiotic resistance. Uropathogenic Escherichia coli (UPEC) isolates pose a threat with a combined expression of multidrug-resistance and biofilm formation. ST131 clone is a high-risk pandemic clone due to its strong association with antimicrobial resistance, which has been reported frequently in recent years. This study aims to define risk factors, clinical outcomes, and bacterial genetics associated with ST131/O25b UPEC. In this study, antibiotic susceptibility and species-level identification of 61 clinical E. coli strains were determined by automated systems. Detection of extended-spectrum beta-lactamases was assessed by double-disk synergy test. Biofilm formation was quantified by spectrophotometric method. Virulence genes (iutA, sfa cnf-1, iroN, afa, papA, fimA), antibiotic resistance genes (blaCTX-M, blaTEM, blaSHV, blaOXA, qnrA, qnrB, qnrS, ant(2')-Ia, ant(3)-Ia, aac(3)-IIa, mcr-1, mcr-2, mcr-3, mcr-4) were investigated by PCR. The following beta-lactamase genes were identified, blaTEM (n = 53, 86.8%), blaCTX-M (n = 59, 96.7%), blaSHV (n = 47, 77.0%), and blaOXA-1 (n = 27, 44.2%). Our data revealed that 93.4% of (57/61) E. coli isolates were biofilm-producers. O25pabBspe and trpA2 were investigated for the presence of ST131/O25b clone. Among multidrug resistant isolates, co-existence of O25pabBspe and trpA2 was detected in 29 isolates (47.5%). The fimH30 and H30Rx subclones were detected in four isolates that are strong biofilm-producers. These results suggest that clinical E. coli strains may become reservoirs of virulence and antibiotic resistance genes. This study demonstrates a significant difference in biofilm formation between E. coli ST131 and non-ST131 isolates. Moreover, 86.21% (n = 25) of ST131 isolates produced strong to moderate biofilms, while only 43.75% (n = 14) of non-ST131 isolates showed the ability to form strong biofilms. Presence of iutA and fimA genes in the majority of ST131 strains showed an important role in biofilm formation. These findings suggest application of iutA and fimA gene suppressors in treatment of infections caused by biofilm-producing drug-resistant ST131 strains.

Multidrug Resistant Group B Streptococcus Isolates from Pregnant Women in Delta State, Nigeria.

&lt;b&gt;Background and Objective:&lt;/b&gt; Group B &lt;i&gt;Streptococci&lt;/i&gt; (GBS) are globally recognized as a major risk factor for neonatal infections and various obstetric complications. More so, biofilm formation has been suggested to be important for GBS pathogenesis. The aim of this study was to determine the prevalence and antibiotic susceptibility pattern of GBS among pregnant women and their capacity to form biofilm. &lt;b&gt;Materials and Methods:&lt;/b&gt; A total of 87 pregnant women at 34 to 37 weeks' gestation aged 17-45 years were recruited from 3 healthcare centres in Delta State, Nigeria. Cultures for the isolation of GBS were carried out using recto-vaginal swabs, according to standard microbiological methods. All strains isolated were used for susceptibility tests to various antibiotics as recommended by CLSI using the disk-diffusion method. &lt;b&gt;Results:&lt;/b&gt; The overall prevalence of GBS colonization among pregnant women was 43.6% (38/87). The &lt;u&gt;<&lt;/u&gt;30 age group had the highest rate of GBS colonization. Resistance to erythromycin and vancomycin was 48.2 and 66.4%, respectively. The fluoroquinolones had the lowest resistant rates with no isolate showing resistance to ofloxacin. Multidrug resistance (MDR) (&lt;u&gt;>&lt;/u&gt;3 drug classes) was detected in 73.7% (28/38) of the GBS isolates. All GBS isolated in this study were either strong, moderate or weak biofilm producers. However, most 28 (73.7%) were strong biofilm producers. Resistance of GBS isolates to erythromycin and vancomycin, drugs used for treating GBS infection was high. &lt;b&gt;Conclusion:&lt;/b&gt; This suggested the importance of testing antimicrobial susceptibilities in GBS colonized pregnant women in order to guide antibiotic therapy and minimize newborn infection and co-morbidity.

Detection of virulent Klebsiella pneumoniae strains causing intestinal and extraintestinal infections during the 80s and 90s in Brazil.

Klebsiella pneumoniae is an important pathogen that causes several human infections, which is currently among the main bacterial species of clinical importance. Given the importance of understanding the characteristics of this pathogen and its evolutionary aspects, in this study, we sought to characterize strains of K. pneumoniae recovered in the 1980s and 1990s in São Paulo, Brazil. Our analyses included 48 strains recovered from diarrheagenic stools and extraintestinal infections. These strains were submitted to screening for virulence and ESβL-encoding genes, antimicrobial susceptibility tests, biofilm formation, and hypermucosity and hemolytic activity tests. Our results revealed that among the studied virulence genes, the most frequent were entB (100%), followed by iutA (100%), mrkD (98%), and ycfM (72%). Phenotypic tests revealed that the strains were non- hemolytic, and two strains were positive for the hypermucoviscosity phenotype but did not have the genetic markers associated with this phenotype. Furthermore, 17% of the isolates proved to be strong biofilm producers. Antimicrobial susceptibility testing demonstrated that most strains were susceptible to the tested antimicrobials, with the exception of five isolates that produced CTX-M-2. Our findings indicate that the collection of strains studied showed variability in virulence factors, as well as biofilm production. Still, a minority of the strains showed clinically significant resistance mechanisms. As far as we know, this is the oldest collection of K. pneumoniae studied in the country.Keywords: Bacterial virulence; Ancient bacterial strains; Enterobacterales; Bacterial infection; Diarrhea.

In treacherous waters: detection of colistin-resistant bacteria in water and plastic litter from a recreational estuary.

Colistin resistance poses a major therapeutic challenge and resistant strains have now been reported worldwide. However, the occurrence of such bacteria in aquatic environments is considerably less understood. This study aimed to isolate and characterize colistin-resistant strains from water and plastic litter collected in an urban recreational estuary. Altogether, 64 strains with acquired colistin resistance were identified, mainly Acinetobacter spp. and Enterobacter spp. From these, 40.6% were positive for at least one mcr variant (1-9), 26.5% harbored, extended-spectrum beta-lactamases, 23.4% harbored, sulfonamide resistance genes, and 9.3% harbored, quinolone resistance genes. merA, encoding mercury resistance, was detected in 10.5% of these strains, most of which were also strong biofilm producers. The minimum inhibitory concentration toward colistin was determined for the mcr-positive strains and ranged from 2 to≥512µg ml-1. Our findings suggest that Gram-negative bacteria highly resistant to a last-resort antimicrobial can be found in recreational waters and plastic litter, thereby evidencing the urgency of the One Health approach to mitigate the antimicrobial resistance crisis.

Molecular Evaluation of Aminoglycoside Resistance and Biofilm Formation Potential in Escherichia coli Isolates Collected from Hospitalized Patients

Background: Resistance to antibiotics and the ability to develop biofilms, two main virulence determinants of Escherichia coli, play a crucial role in the persistence of infections. Objectives: The aim of this study was to evaluate aminoglycoside resistance and biofilm formation potential in E. coli isolates collected from hospitalized patients in the Southwest of Iran. Methods: A total of 70 E. coli clinical isolates from different specimens were collected from Ahvaz teaching hospitals affiliated with Ahvaz Jundishapur University of Medical Sciences. All the isolates were identified as E. coli using conventional microbiological tests. Susceptibility to antibiotics was determined using the Kirby–Bauer disk diffusion method. Biofilm formation was assessed using the microtiter plate method. Finally, PCR was conducted to detect virulence gene determinants, including fimbrial genes, aminoglycoside modifying enzymes (AMEs), and 16S rRNA methylase (RMTase) genes. Results: Among aminoglycoside antibiotics, E. coli isolates showed the highest and lowest resistance rates to tobramycin (TOB; 51.4%) and gentamicin (GEN; 24.2%), respectively. Simultaneous resistance to GEN, amikacin, and TOB was observed in 28.5% of the isolates, representing the most common antibiotic resistance pattern. The prevalence of strong biofilm producers was higher in the extensively drug-resistant (XDR) phenotype group compared to the multiple drug-resistant (MDR) group (76.1% vs. 23.8%). Among the 36 isolates resistant to at least one of the aminoglycoside antibiotics, 36.1% had AME-related genes, either alone or in various combinations. Most isolates harboring AME genes were also positive for the presence of biofilm-related genes, including ecpA and fimA. Conclusions: The most frequent AME-related genes were ant(2”)-Ia and aph(3’)-Ia, followed by aac(3’)-IIa. The findings of the present study provide probable evidence that GEN is an effective aminoglycoside against biofilm-producing and antibiotic-resistant E. coli isolates.

Agroclimatic zone-wise prevalence of biofilm forming methicillin resistant staphylococcus aureus in West Bengal

The present study envisages the prevalence of biofilm producing, methicillin resistant Staphylococcus aureus, isolated from cattle milk of different agro-climatic zones of an eastern state of India, West Bengal. The milk samples (n=168) were collected from three predominant agro- climatic zones of South Bengal, viz. new alluvial, coastal saline and red laterite. A total of 146 Staphylococcus aureus isolates were recovered, confirmed by biochemical tests and polymerase chain reaction (PCR). Through PCR of mecA gene, it was found that 45 strains were methicillin resistant, encompassing 28.57% new alluvial zone, 30.19% red laterite region and 29.16% coastal saline region. Determination of biofilm formation was done, both phenotypically by microtiter plate method and genotypically by PCR of icaA and icaD genes, specific for biofilm formation in Staphylococcus aureus. Phenotypic study revealed that 14 isolates were strong biofilm producers, 79 were moderate and the 47 were weak biofilm producers. PCR studies also showed that a total of 30 isolates were icaA positive and 25 isolates were icaD positive. Although no significant difference was found in the occurrence of icaA positive isolates, the possession of icaD by the Staphylococcus aureus isolates varied significantly according to different agro-climatic zones.

Characterization of biofilm-forming ability and antibiotic resistance profiles of clinical Pseudomonas aeruginosa isolates from patients with cystic fibrosis

Background: Pseudomonas aeruginosa is a key pathogen in cystic fibrosis (CF) associated infections, known for its biofilm-forming ability and resistance to multiple antibiotics. Understanding the relationship between biofilm production and antibiotic resistance profiles in clinical isolates can guide treatment strategies. Aims and Objectives: The aims of this study were to investigate the biofilm-forming abilities and antibiotic resistance profiles of clinical P. aeruginosa isolates from patients with CF and to determine the relationship between these two factors and their impact on treatment efficacy. Materials and Methods: A cross-sectional study was conducted on 100 clinical isolates of P. aeruginosa from CF patients. Biofilm-forming capacity was categorized as strong, moderate, or weak based on quantitative assays. Antibiotic resistance was assessed for ciprofloxacin, tobramycin, ceftazidime, meropenem, and piperacillin/tazobactam. Multi-drug resistance was defined as resistance to three or more antibiotic classes. Statistical correlations between biofilm-forming capacity and resistance levels were evaluated using the Chi-square tests. Results: Fifty-six percentages of isolates were strong biofilm producers, while 34% and 10% were moderate and weak producers, respectively. The highest antibiotic resistance was observed against ciprofloxacin (60%), followed by tobramycin (50%) and ceftazidime (45%). Forty percentages of the isolates were classified as multi-drug resistant. Strong biofilm producers demonstrated a significantly high correlation with antibiotic resistance (P&lt;0.05). Two predominant clonal groups were identified among the isolates, suggesting a possible clonal spread of resistance traits. Conclusion: The study confirms a strong association between robust biofilm production and heightened antibiotic resistance in P. aeruginosa isolates from CF patients. These findings highlight the need for targeted therapeutic strategies to disrupt biofilm formation and curb resistance spread.

Evaluation of biofilm formation by bacteria isolated from engine oil-contaminated soil and exploring its bioremediation potential in vitro

This study investigated the biofilm-forming ability of bacteria isolated from engine oil-contaminated soil and assessed their potential for bioremediation. Fifteen engine oil contaminated soil samples were collected and inoculated into Bushnell-Haas (BH) broth supplemented with 2 % engine oil. After incubation, bacterial colonies were isolated and identified using 16s RNA sequencing. The tube adherence test also known as Christensen method and modified microtiter plate quantification of biofilm formation by Stepanović et al. (2000) [1], was used to study bacterial biofilm as tube test and the microtiter-plate test are the most frequently used techniques for quantifying biofilm formation was used to study bacterial biofilm. Both quantitative (OD measurements) and qualitative (visual observation) methods were employed, classifying the six isolates into three categories: strong, moderate, and low biofilm producers. Among the 6 bacterial isolates, Stutzerimonas stutzeri exhibited the highest biofilm-forming ability.Oil degradation capacity of the isolates were tested individually as monocultures and co-cultures with other isolates. Results showed that the co-culture of Stutzerimonas stutzeri and Klebsiella quasipneumoniae showed significantly higher oil degradation compared to their monoculture and other co-cultures, suggesting synergistic interactions between the two bacterial species.However, Stutzerimonas stutzeri alone exhibited good oil degradation potential and is more useful for bioremediation but Klebsiella quasipneumoniae's rare pathogenicity, may not be suitable for field application. This study highlights biofilm-forming bacteria, particularly Stutzerimonas stutzeri, as a potential solution for bioremediating engine oil-contaminated sites.

Unveiling the microevolution of antimicrobial resistance in selected Pseudomonas aeruginosa isolates from Egyptian healthcare settings: A genomic approach

The incidence of Pseudomonas aeruginosa infections in healthcare environments, particularly in low-and middle-income countries, is on the rise. The purpose of this study was to provide comprehensive genomic insights into thirteen P. aeruginosa isolates obtained from Egyptian healthcare settings. Phenotypic analysis of the antimicrobial resistance profile and biofilm formation were performed using minimum inhibitory concentration and microtiter plate assay, respectively. Whole genome sequencing was employed to identify sequence typing, resistome, virulome, and mobile genetic elements. Our findings indicate that 92.3% of the isolates were classified as extensively drug-resistant, with 53.85% of these demonstrating strong biofilm production capabilities. The predominant clone observed in the study was ST773, followed by ST235, both of which were associated with the O11 serotype. Core genome multi-locus sequence typing comparison of these clones with global isolates suggested their potential global expansion and adaptation. A significant portion of the isolates harbored Col plasmids and various MGEs, all of which were linked to antimicrobial resistance genes. Single nucleotide polymorphisms in different genes were associated with the development of antimicrobial resistance in these isolates. In conclusion, this pilot study underscores the prevalence of extensively drug-resistant P. aeruginosa isolates and emphasizes the role of horizontal gene transfer facilitated by a diverse array of mobile genetic elements within various clones. Furthermore, specific insertion sequences and mutations were found to be associated with antibiotic resistance.

Biofilm-producing ability of methicillin-resistant Staphylococcus aureus clinically isolated in China

BackgroundStaphylococcus aureus, a commensal bacterium, colonizes the skin and mucous membranes of approximately 30% of the human population. Apart from conventional resistance mechanisms, one of the pathogenic features of S. aureus is its ability to survive in a biofilm state on both biotic and abiotic surfaces. Due to this characteristic, S. aureus is a major cause of human infections, with Methicillin-Resistant Staphylococcus aureus (MRSA) being a significant contributor to both community-acquired and hospital-acquired infections.ResultsAnalyzing non-repetitive clinical isolates of MRSA collected from seven provinces and cities in China between 2014 and 2020, it was observed that 53.2% of the MRSA isolates exhibited varying degrees of ability to produce biofilm. The biofilm positivity rate was notably high in MRSA isolates from Guangdong, Jiangxi, and Hubei. The predominant MRSA strains collected in this study were of sequence types ST59, ST5, and ST239, with the biofilm-producing capability mainly distributed among moderate and weak biofilm producers within these ST types. Notably, certain sequence types, such as ST88, exhibited a high prevalence of strong biofilm-producing strains. The study found that SCCmec IV was the predominant type among biofilm-positive MRSA, followed by SCCmec II. Comparing strains with weak and strong biofilm production capabilities, the positive rates of the sdrD and sdrE were higher in strong biofilm producers. The genetic determinants ebp, icaA, icaB, icaC, icaD, icaR, and sdrE were associated with strong biofilm production in MRSA. Additionally, biofilm-negative MRSA isolates showed higher sensitivity rates to cefalotin (94.8%), daptomycin (94.5%), mupirocin (86.5%), teicoplanin (94.5%), fusidic acid (81.0%), and dalbavancin (94.5%) compared to biofilm-positive MRSA isolates. The biofilm positivity rate was consistently above 50% in all collected specimen types.ConclusionsMRSA strains with biofilm production capability warrant increased vigilance.

Coexistence of β-lactamase genes and biofilm forming potential among carbapenem-resistant Acinetobacter baumannii in Lahore, Pakistan.

Our goal was to investigate the antimicrobial resistance due to beta-lactamase genes and virulent determinants (biofilm-forming ability) expressed by Acinetobacter collected from health settings in Pakistan. A cross-sectional study was conducted for the molecular characterization of carbapenemases and biofilm-producing strains of Acinetobacter spp. Two twenty-three imipenem-resistant Acinetobacter isolates were analyzed from 2020 to 2023.The combination disk test and modified hodge test were performed. Biofilm forming ability was determined by polystyrene tube assay. Multiplex polymerase chain reaction (PCR) for virulent and biofilm-forming genes, and 16S rRNA sequencing were performed. 118 (52.9%) carbapenem-resistant Acinetobacter (CR-AB) were isolated from wounds and pus, 121 (54.2%) from males, and 92 (41.2%) from 26-50-years-olds. More than 80% of strains produced β-lactamases and carbapenemases. Based on the PCR amplification of the ITS gene, 174 (78.0%) CR-AB strains were identified from CR-Acinetobacter non-baumannii (ANB). Most CR-AB were strong and moderate biofilm producers. Genetic analysis revealed the blaOXA-23, blaTEM, blaCTX-M blaNDM-1 and blaVIM were prevalent in CR-AB with frequencies 91 (94.8%), 68 (70.8%), 19 (19.7%), 53 (55.2%), 2 (2.0%) respectively. Among virulence genes, OmpA was dominant in CR-AB isolates from wound (83, 86.4%), csuE 63 (80.7%) from non-wound specimens and significantly correlated with blaNDM and blaOXA genes. Phylogenetic analysis revealed three different clades for strains based on specimens. CR-AB was highly prevalent in Pakistan and associated with wound infections. The genes, blaOXA-23, blaTEM, blaCTX-M, and blaNDM-1 were detected in CR-AB. Most CR-AB were strong biofilm producers with virulent genes OmpA and csuE.