Detection Of Biofilm Formation Research Articles

Therapeutic efficiency of probiotic lactobacillus acidophilus, lactobacillus rhamnosus and antibiotic against isolates of pathogenic bacterial from skin wound infections

Background: Probiotic refer to harmless live normal flora micro-organisms (M.O), which are mostly strains of Lactobacillus spp., Bifidobacterium spp., and others. These microorganisms (M.O) help the host's health when given in the right dosages. Aims: To identify bacterial species isolated from wound infections, and also to evaluate in-vitro the antimicrobial activity of selected probiotic species and antibiotic against some pathogenic bacteria. Methods: Records of wound swabs collected from 102 patients with high suspicion of wound infections. Bacterial colonies were Gram stained and microscopically examined. Biochemical tests were done to identify pathogen species. The microtitre plate method (MTP) was used to detect biofilm formation by bacteria. The Kirby-Bauer disk diffusion method was used for antibiotic testing. The well diffusion method and agar spot method was used for detection probiotic affectivity to a group of bacteria isolated (totally 38 isolates). Results: Prevalence of wound infections was 81.4% (CI: 60.869). A total of 10 species were isolated from 83 infected wounds. The most common bacterial species detected was Staphylococcus aureus (26.5%), followed by Pseudomonas aeruginosa 14.4%, Proteus mirabilis (12%), Escherichia coli 10.8%, and Enterobacter cloacae (8.4%). Polymicrobial infection was found in 25(30.1%) of the samples and was mainly constituted with two species.

Biofilm Formation by Uropathogens and Its Impact on Antimicrobial Susceptibility Pattern

Background: Out of all Hospital-Associated Infections (HAIs),Urinary Tract Infection (UTI) is the second most common infection that accounts for approximately 34%, and 80% are associated with indwelling catheters and hence with biofilm formation, which invites multi-drug resistant microorganisms. The present study was designed to study in-vitro biofilm forming uropathogens and their antimicrobial susceptibility in a tertiary care hospital in north India. Method:The present cross-sectional study consisted of 200 urine specimens collected over one year from patients with symptoms of urinary tract infection. Following their isolation and identification, all the isolates were subjected to screening for biofilm formation by Congo Red Agar (CRA) and the Tube Adherence (TA) methods. Subsequently, the Kirby Bauer-disk diffusion method performed the antimicrobial susceptibility test. Results: Out of the total samples (n = 200), a total of 46 (23%) were positive by the CRA method, while 33 (16.5%) were positive by the TA method. Twenty-one (21%) isolates came positive by both methods. Biofilm formation was seen more commonly in females (82%). Biofilm-forming uropathogens develop significantly higher resistance to antimicrobial drugs than non-producers. Conclusion: The correlation was significant between biofilm production and multidrug resistance. Also, it was concluded that the CRA method could be employed to detect biofilm formation in resource-limited countries.

Biofilm-Associated Multi-Drug Resistance in Hospital-Acquired Infections: A Review.

Biofilm-related multi-drug resistance (MDR) is a major problem in hospital-acquired infections (HAIs) that increase patient morbidity and mortality rates and economic burdens such as high healthcare costs and prolonged hospital stay. This review focuses on the burden of bacterial biofilm in the hospital settings, their impact on the emergence of MDR in the HAIs, biofilm detection methods, recent approaches against biofilms, and future perspectives. The prevalence of biofilm-associated MDR among HAIs ranges from 17.9% to 100.0% worldwide. The predominant bacterial isolates causing HAIs in recently published studies were S. aureus, A. baumannii, K. pneumoniae, and P. aeruginosa. In addition to the use of qualitative and quantitative methods to detect biofilm formation, advanced PCR-based techniques have been performed for detecting biofilm-associated genes. Although there are suggested therapeutic strategies against biofilms, further confirmation of their efficacy for in vivo application and antibiotics targeting biofilm-associated genes/proteins to minimize treatment failure is required for the future.

Investigation of Biofilm Virulence Genes Prevalence in Klebsiella pneumoniae Isolated from the Urinary Tract Infections.

Klebsiella pneumonia is a pathogen and an agent that causes hospital-acquired infections. Klebsiella pneumonia is the first and most common causative agent in community-acquired infections and urinary tract diseases. This study aimed to detect common genes, (i.e., fimA, mrkA, and mrkD) in the isolates of K. pneumoniae, isolated from urine specimens using the polymerase chain reaction (PCR) method. The isolates of K. pneumoniae were collected from urine specimens in health centers in Wasit Governorate, Iraq, and diagnosed using AnalyticalProfile Index20Eand 16S rRNA techniques. The microtiter plate (MTP) method was used to detect biofilm formation. A total of 56 isolates were identified as K. pneumonia cases. The results led to the detection of biofilms; accordingly, all K. pneumoniae isolates showed biofilm production by MTP, however, at different levels. The PCR method was employed to detect biofilm genes and showed that 49 (87.5%), 26 (46.4%), and 30 (53.6%) of isolates carried fimH, mrkA, and mrkD, respectively. Furthermore, susceptibility tests for different antibiotics revealed that K. pneumoniae isolates were resistant to amoxicillin-clavulanic acid (n=11, 19.5%), ceftazidime (n=13, 22.4%), ofloxacin (n=16, 28.1%), and tobramycin (n=27, 48.4%). It was also found all K. pneumonia isolates were sensitive to polymyxin B (92.6%), imipenem (88.3%), meropenem (79.4%), and amikacin (60.5%).

Detection of Biofilm Formation on Material Surfaces by Ag+ Coating

The evaluation of biofilm formation is important, given the ubiquity and problematic nature of biofilms in industrial and medical settings, as well as in everyday life. Basically, biofilms are formed on substrates. Therefore, it is essential to consider the properties of the substrates during biofilm evaluation. The common dye staining method to evaluate biofilm formation requires a short evaluation time and enables the evaluation of a large area of the sample. Furthermore, it can be easily determined visually, and quantitative evaluation is possible by quantifying color adsorption. Meanwhile, the dye staining method has the problem of adsorption even on substrate surfaces where no biofilm has formed. Therefore, in this study, we focused on Ag+ reduction reaction to devise a novel biofilm evaluation method. Ag+ is highly reductive and selectively reacts with organic substances, such as saccharides, aldehydes, and proteins contained in biofilms, depositing as metallic Ag. First, to simply evaluate biofilm formation, we used a glass substrate as a smooth, transparent, and versatile oxide material. We observed that the amount of Ag deposited on the substrate was increased proportionally to the amount of biofilm formed under light irradiation. Upon comparing the Ag deposition behavior and adsorption behavior of crystal violet, we discovered that for short immersion times in AgNO3 solution, Ag deposition was insufficient to evaluate the amount of biofilm formation. This result suggests that the Ag reduction reaction is more insensitive than the crystal violet adsorption behavior. The results of the Ag deposition reaction for 24 h showed a similar trend to the crystal violet dye adsorption behavior. However, quantitative biofilm evaluation using the proposed method was difficult because of the Ag+ exchange with the alkali metal ions contained in the glass substrate. We addressed this issue by using the basic solution obtained by adding an ammonia solution to aqueous AgNO3. This can cause Ag+ to selectively react with the biofilm, thus enabling a more accurate quantitative evaluation. The optimum was determined at a ratio of distilled water to aqueous ammonia solution of 97:3 by weight. This biofilm was also evaluated for materials other than ceramics (glass substrate): organic material (polyethylene) and metal material (pure iron). In the case of polyethylene, a suitable response and evaluation of biofilm formation was successfully achieved using this method. Meanwhile, in the case of pure iron, a significantly large lumpy deposit of Ag was observed. The likely reason is that Ag precipitation occurred along with the elution of iron ions because of the difference in ionization tendency. It could be concluded that the detection of biofilm formation using this method was effective to evaluate biofilm formation on materials, in which the reduction reaction of [Ag(NH3)2]+ does not occur. Thus, a simple and relatively quantitative evaluation of biofilms formed on substrates is possible using this method.

Investigating Biofilm Formation and Antibiofilm Activity Using Real Time Cell Analysis Method in Carbapenem Resistant Acinetobacter baumannii Strains.

Acinetobacter baumannii is a significant nosocomial pathogen, with its biofilm forming capacity playing an important role in its pathogenicity. The fast and reliable detection of the biofilm formation and measurement of antibiofilm activity of various molecules are critical for combating A. baumannii infections. In this study, we aimed to detect biofilm formation by real time cell analyses (RTCA) method in clinical A. baumannii isolates and to investigate antibiofilm activities of tigecycline (TGC), N-acetylcysteine (NAC), and acetylsalicylic acid (ASA). The effect of the tested drugs on expressions of biofilm-related genes bap and csuE in clinical A. baumannii strains was also analyzed by real time quantitative reverse transcription polymerase chain reaction (RT-qPCR). Biofilm forming capacities for strong and weak biofilm producer A. baumannii strains were detected within 10h by RTCA method (P < 0.05). We also observed that sub-minimum inhibitory concentrations of NAC + TGC and ASA + TGC combinations could significantly reduce biofilm formation and expression of biofilm-related genes in A. baumanii strains. No statistically significant activity of the tested drugs was detected against mature biofilms of the bacterial strains with the RTCA method. These results suggest that reproducible results on biofilm production capacity of A. baumannii strains and antibiofilm activities of various compounds can be obtained in a short time using RTCA method. Therefore, RTCA method seems to be a beneficial technique for biofilm detection and can help in combating A. baumannii infections by giving health providers the opportunity of implementing antibiofilm treatment strategies in a timely manner.

Phenotypic and genotypic study associated with biofilm formation for E. coli isolated from UPEC

UTI is a serious health problem with respect to antibiotic resistance and biofilms formation being the prime cause for the antibiotic resistance. In current study sixty E.coli isolated collected from patients with urinary tract infection. In this study, biofilm formation were detect by phenotypic and genotypic methods. The detection of biofilm formation by phenotypic method was carried out by Congo Red Agar (CRA) method and tissue culture plate (TCP) method and the genotypic method performed by detection present some gene associated with biofilm formation which include fliC ,csgA ,fimH and papC.. The results showed that 54(90%) from E. coli produced strong and moderate slime layer. The present study showed that 57(95%) from E. coli produced strong and moderate biofilm. Genotypic study of E. coli biofilm-associated genes were found in various frequencies in all isolates that included fliC (63.3%), csgA (73.3%), fimH (90%) and papC (76.6%).

Biofilm Formation and Its Association with Antimicrobial Resistance among Clinical Isolates of Acinetobacter baumanii at a Tertiary Care Hospital in Dhaka City of Bangladesh

Background: Acinetobacter baumanii is responsible for nosocomial infections which are related to the biofilm forming capacity of this pathogen.&#x0D; Objective: The purpose of the present study was to detect biofilm formation in clinical isolates of Acinetobacter baumannii and to observe relationship between biofilm formations with its antimicrobial resistance.&#x0D; Methodology: This cross-sectional study was conducted in the Department of Microbiology of Dhaka Medical College and Hospital, Dhaka, Bangladesh from July 2015 to June 2016. Acinetobacter baumannii was isolated from different specimens and was identified and were screened for biofilm production by tissue culture plate method. Antimicrobial susceptibility test was done by disc diffusion method.&#x0D; Results: A total 300 samples were studied of which 26(8.7%) were Acinetobacter baumannii. From 26 isolated Acinetobacter baumannii, 16(61.5%) were biofilm producers. Biofilm producing Acinetobacter baumannii were 100% resistant to ceftriaxone, ceftazidime, amoxiclav, amikacin and ciprofloxacin. Resistance to imipenem, meropenem, cephotaxime, cefepime and gentamicin were also higher among biofilm producing Acinetobacter baumannii isolates than non-biofilm producers.&#x0D; Conclusions: In conclusion the ability of Acinetobacter baumannii forms biofilm and biofilm production has strong association with antimicrobial resistance.&#x0D; Bangladesh Journal of Infectious Diseases December 2021;8(2):82-86

A risk-oriented evaluation of biofilm and other influencing factors on biological quality of drinking water for dairy cows.

Despite the importance of livestock drinking water quality on animal physiology, welfare, and performance, influences such as biofilm formation on trough surfaces on microbial water quality are rarely researched. The objective of this study was to assess the microbial quality of water offered to lactating dairy cows and identify risk factors for poor water quality. We further aimed to determine the impact of biofilm formation on water quality and evaluate rapid test systems to score the hygiene status of dairy troughs on the farm. A total of 105 troughs located on 24 typical Western German dairy farms were sampled. Samples of livestock drinking water and biofilm were analyzed for aerobic total viable count (TVC), coliform count (CC), Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA), and other bacteria resistant to 3rd generation cephalosporins (CRB). Surface protein- and adenosine triphosphate (ATP)-rapid tests were evaluated to detect biofilm formation. The influence of 22 selected fixed and variable trough characteristics on impaired livestock drinking water quality was evaluated by calculating odds ratios. The average TVC, CC, and E. coli counts were 4.4 ± 0.06 (mean ± SD), 1.7 ± 0.1, and 0.6 ± 0.1 log10 cfu per mL, respectively. CC was detectable in 94.3% of all water samples and E. coli in 48.6%. MRSA was found in pooled livestock drinking water samples of a single farm and CRB on three farms, suggesting that troughs might function as a reservoir of antibiotic-resistant bacteria, thereby contributing to an exchange of antibiotic-resistant bacteria between animals. Risk factors for the impairment of at least one microbial quality criteria (TVC, CC, or E. coli) increased significantly (P < 0.05) when using high-volume troughs, other trough materials than stainless steel, a lower distance to the milking parlor, heavy visible soiling, biofilm formation, and high ambient and high water temperatures. CC (r = 0.46; P < 0.001) and E. coli (r = 0.31; P < 0.01) of water samples correlated with their equivalent in biofilm and with the results of rapid tests on trough surfaces (0.31 > r > 0.19; P < 0.05). Addressing the identified risk factors could be an approach to ensure sufficient biological quality of livestock drinking water.

Diabetic Foot Ulcer Infections and Pseudomonas aeruginosa Biofilm Production During the COVID-19 Pandemic

During the different waves of the coronavirus (COVID-19) pandemic, there has been an increased incidence of diabetes mellitus and diabetic foot infections. Among gram-negative bacteria, Pseudomonas aeruginosa is the predominant causative agent for diabetic foot ulcer infections in low-resource countries. P. aeruginosa possesses a variety of virulence factors, including biofilm formation. Biofilm formation is an important benchmark characteristic in the pathophysiology of diabetic foot ulceration. The main objective of the current study was to identify the most commonly isolated organisms and their antibiotic susceptibility patterns in diabetic foot patients during the COVID-19 pandemic. We also determined the genes associated with bacterial persistence and biofilm formation in the predominantly isolated organism. Accordingly, 100 wound swab samples were collected from diabetic foot patients from different hospitals in Alexandria, Egypt. Through phenotypic detection of biofilm formation, 93% (40) of the 43 P. aeruginosa isolates examined were categorized as biofilm producers. Molecular detection of the biofilm-encoding genes among the 43 P. aeruginosa isolates was as follows: algD (100%), pelF (88%) and pslD (49.7%), and this highlights a need for biofilm formation inhibitors to prevent the persistence of bacterial pathogens, and thus achieve better clinical outcomes in diabetic foot ulcer infections.

Detection of biofilm formation and fimH gene in Escherichia coli isolated from urine samples of bovine

Detection of biofilm formation and fimH gene in Escherichia coli isolated from urine samples of bovine

ANTIBIOTIC RESISTANCE, MECA GENE DETECTION, AND BIOFILM FORMATION ABILITY AMONG COAGULASE-NEGATIVE STAPHYLOCOCCI IN CANCER PATIENTS

Objective: The objective of the study was to identify coagulase-negative staphylococci (CoNS) from various clinical samples and to determine the antibiotic resistance of the isolates by means of automation (VITEK-2), as well as to detect biofilm formation using Congo red agar method and to detect mecA gene by automated identification method (VITEK-2). Methods: All the clinical samples (blood, urine, sputum, BAL, throat swab, wound swab, aspirated fluid, pleural fluid, and pus) received in the microbiology laboratory were processed by aseptic techniques. Clinical samples were inoculated on appropriate media (blood agar, MacConkey agar, and chocolate agar [HIMEDIA]). After inoculation, the culture plates were incubated at 37°C aerobically for 18–24 h for growth. Positive cultures were picked up and further bacterial species identification was done using automated techniques (MALDI- TOF). Results: Among 28 isolates, the most recurrent strains of CoNS are Staphylococcus epidermidis, Staphylococcus hominis, Staphylococcus lugdunensis, and Staphylococcus haemolyticus. The assessment of antibacterial drugs sensitivity shows that all the isolates were more sensitive to daptomycin (S. epidermidis 100%, S. hominis 100%, S. lugdunensis 100%, and S. haemolyticus 42.85%) followed by linezolid (S. epidermidis [69.23%], S. hominis [100%], S. lugdunensis [100%], and S. haemolyticus [57.14%]) and vancomycin (S. epidermidis [100%], S. hominis [40%], S. lugdunensis [100%], S. haemolyticus [42.85%]). The analysis revealed the presence of the mecA gene (67.85%) and biofilm production (85.71%), respectively. Conclusion: Our data indicate that the hospital environment can be colonized by biofilm forming CoNS and transmission of these strains can cause an increased risk of serious nosocomial infections.

Antibiotic Susceptibility, Biofilm Production, and Detection of mecA Gene among Staphylococcus aureus Isolates from Different Clinical Specimens.

The increasing incidence of methicillin-resistant and biofilm-forming S. aureus isolates in hospital settings is a gruesome concern today. The main objectives of this study were to determine the burden of S. aureus in clinical samples, assess their antibiotic susceptibility pattern and detect biofilm formation and mecA gene in them. A total of 1968 different clinical specimens were processed to isolate S. aureus following standard microbiological procedures. Antibiotic susceptibility test of the isolates was performed by Kirby–Bauer disc-diffusion method following CLSI guidelines. Biofilm was detected through tissue culture plate method. Methicillin-resistant S. aureus (MRSA) isolates were screened using cefoxitin (30 µg) discs and mecA gene was amplified by conventional polymerase chain reaction (PCR). Of 177 bacterial growth, the prevalence of S. aureus was 15.3% (n = 27). MRSA were 55.6% (15/27) and 44% (12/27) exhibited multidrug resistance (MDR). There was no significant association between methicillin resistance and MDR (p > 0.05). Both MRSA and MSSA were least sensitive to penicillin (100%, 75%) followed by erythromycin (86.6%, 66.6%). Most of the MRSA (93.4%) were susceptible to tetracycline. All S. aureus isolates were biofilm producers—19 (70%) were weak and only one (4%) was a strong biofilm producer. The strong biofilm-producing MSSA was resistant to most of the antibiotics except cefoxitin and clindamycin. None of the MSSA possessed mecA gene while 8 (53.3%) MRSA had it. More than half of S. aureus isolated were MRSA. High incidence of multidrug resistance along with capacity to form biofilm among clinical isolates of S. aureus is a matter of apprehension and prompt adoption of biosafety measures is suggested to curb their dissemination in the hospital environments.

Detection of biofilm formation, extended spectrum beta lactamase production and their correlation with antibiotic resistance among uropathogenic Escherichia coli

Urinary tract infections (UTI) are most common bacterial infections encountered in clinical practice and is predominant organism causing UTI.: 1.To study antibiotic resistance pattern among uropathogenic (UPEC). 2.To study extended spectrum beta lactamase (ESBL) production and their correlation with antibiotic resistance among uropathogenic (UPEC). 3.To study biofilm formation and its correlation with antibiotic resistance among uropathogenic (UPEC)A prospective study was conducted on first 100 isolated from urine specimens of patients suspected to be having urinary tract infection between January 2016 and December 2016 received at Department of Microbiology, SIMS Shimoga. Fresh midstream urine samples were aseptically collected in sterile containers and plated on Blood agar &amp; MacConkey agar plates using a standard loop technique &amp; the growth was processed by standard bacteriological technique. Biofilm detection was done by tube and microtitre plate method. ESBL detection was done according to CLSI criteria. Antimicrobial sensitivity testing was done using Kirby-Bauer methods on Mueller-Hinton agar. Results were interpreted as per the CLSI guidelines.Antibiotic sensitivity of was nitrofurantoin (100%) fosfomycin (100%) imipenem (77%) cotrimoxazole (61%) amikacin (47%) aztreonam (53%) piperacillintazobactam (41%). cefotaxim (25%) ceftazidime (32%) norfloxacin (20%) ampicillin-sulbactam (12%) ciprofloxacin (15%), levofloxacin (12%), amoxiclavulanicacid (15%). ESBL positive were 83% (screening), 80% (confirmatory). Biofilm positive were 63% (tube method) 79% (Microtiterplate method).This study showed Fosfomycin and Nitrofurantoin were the most sensitive drug. Study shows antibiotic resistance was seen more in ESBL and Biofilm producers compared to non ESBL and non biofilm producers.

Evaluation of phenotypic methods in the detection of biofilm formation and antibiotics susceptible patterns among the enterococci isolates

Evaluation of phenotypic methods in the detection of biofilm formation and antibiotics susceptible patterns among the enterococci isolates

Evaluation of phenotypic methods in the detection of biofilm formation and antibiotics susceptible patterns among the enterococci isolates

Evaluation of phenotypic methods in the detection of biofilm formation and antibiotics susceptible patterns among the enterococci isolates

Evaluation of Antibiotic Resistance and Biofilm Production among Clinical Strain Isolated from Medical Devices.

Microbial biofilms pose a serious threat to patients requiring medical devices (MDs). Prolonged periods of implantation carry a high risk of device-related infections (DRIs). Patients with DRIs often have negative outcomes following the failure of antibiotic treatment. Resistant DRIs are mainly due to the MDs contamination by bacteria producing biofilm. The present study aimed to detect biofilm formation among MD bacterial isolates and to explore their antibiotic resistance profile. The study was conducted on 76 MDs, collected at University Hospital of Campania “Luigi Vanvitelli,” between October 2019 and September 2020. Identification of isolates and antibiotic susceptibility testing were performed using Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) and Phoenix Becton Dickinson, respectively. Biofilm-forming abilities were assessed using the tissue culture plate (TCP) method. Among the 94 MDs isolated strains, 42.7% were Gram-positive, 40.3% Gram-negative, and 17% Candida species. Among 78 bacterial strains, 43.6% were non-biofilm producers while 56.4% produced biofilms. All biofilm producing isolates were sensitive to a limited spectrum of antibiotic classes. All moderate and strong biofilm producers and 81% of weak biofilm producers were Multidrug Resistance (MDR) strains. In contrast, among non-biofilm producers, only 11.8% were classified as MDR strains. Our results highlighted that Sulfamides and Glycopeptides for the major Gram-positive strains and Fluoroquinolones, Carbapenems, and Aminoglycosides for the most represented Gram-negative isolates could be the most suitable therapeutic choice for most biofilm-DRIs.

Comparative study of biofilm formation in tubotympanic and atticoantral ear disease

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Biofilm is an organized bacterial community that may be homogeneous or heterogeneous. It plays a significant role in the pathogenesis of chronic rhinosinusitis, chronic tonsillitis and chronic suppurative otitis media. Biofilms may explain the recurrence and recalcitrant episodes of otorrhea in chronic otitis media (COM). The objective of this study was to detect biofilm formation in chronic suppurative otitis media and compare the pattern of biofilm formation in tubotympanic and atticoantral ear diseases.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; This was a prospective cross sectional study at a tertiary care hospital in Varanasi, Uttar Pradesh, India. Patients included in the study ranged from 10 to 65 years of age from both the sexes and varying socioeconomic status. Samples were collected using sterile precautions in cases of tubotympanic as well as atticoantral COM. The collected samples were directly inoculated onto MacConkey and blood agar media. LisaScan® EM microtitter plate reader was used to identify the presence of biofilm.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; The most common organism was &lt;em&gt;P. aeruginosa&lt;/em&gt; and &lt;em&gt;S. aureus&lt;/em&gt; followed by &lt;em&gt;Moraxella catarrhalis&lt;/em&gt; whereas in cases with tubotympanic COM, most common organism was &lt;em&gt;S. aureus&lt;/em&gt;. We found that, in atticoantral type of COM biofilm formation was significantly more common as compared to that in tubotympanic type of COM.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Biofilm formation in COM is even higher when atticoantral disease is present.&lt;/p&gt;

LuxS Gene and Biofilm Formation in Streptococcus uberis Isolated from Bovine Mastitis Cases

Background: Streptococcus uberis (S. uberis) is an environmental pathogen causing mastitis in Dairy cattle. It causes recurrent mastitis and reduction in milk production in livestock causing economic loss. The prevalence of S. uberis intramammary infections is due to ability of the organism to form biofilm in udder tissue. The present study is on in-vitro biofilm production, the correlation of luxS gene and the biofilm formation in S. uberis. Methods: A total of 91 mastitic milk samples were collected from cattle and buffaloes brought at Veterinary Hospitals and farms in Krishna, Guntur and West Godavari districts, Andhra Pradesh. The identification of the culture isolates was based on cultural and biochemical characteristics and confirmed by Polymerase Chain Reaction (PCR). The Streptococcus species cultures showing greyish, pinpointed colonies and/or aesculin hydrolysis on Edwards medium were further identified by various biochemical tests viz., catalase test, ninhydrin test, sodium hippurate hydrolysis test and type of haemolysis on 7% sheep blood agar. Confirmation of the isolates by PCR was followed by detection of biofilm formation using qualitative Congo red agar (CRA) method, quantitative microtiter plate (MTP) assay and biofilm gene (luxS) was detected using PCR.Conclusion: From this study it is suggestable that for biofilm study both phenotypic and genotypic methods should be taken together which can be influenced by various other factors also. MTP assay was a good choice for quantitative biofilm determination, which was giving a more accurate and understandable results. The results express that any of the isolates without luxS didn’t produce a strong biofilm and it is concluded that there may be other genes for regulation of biofilm production and/or luxS gene has a regulatory role for one or more genes related to biofilm formation in S. uberis.

Detection of biofilm formation among Pseudomonas aeruginosa isolated from burn patients

BackgroundPseudomonas aeruginosa is an opportunistic bacterium that rapidly colonised on the exacerbated skin surface after the burn injury. Along with inherent resistance to many antibiotics, it is also a good biofilm producer that aggravates the condition of burns patients by slow or non-responsive to antibiotics. Therefore, immediate attention must be taken otherwise the condition of patients may become life-threatening. Hence, this cross-sectional study was conducted to know the current scenario of antimicrobial profile and biofilm properties of Pseudomonas aeruginosa isolated from burn patients in Nepal Cleft and Burn Centre, Kirtipur Hospital. MethodsWound swab or pus samples were taken from 344 patients through the Levine technique or syringe, respectively. The standard laboratory protocol was followed for the identification of Pseudomonas aeruginosa. The antibiotic susceptibility test of isolates was performed by using the Kirby-Bauer disc diffusion method as per the CLSI 2018 guidelines. Biofilm production was accessed through the tube method and microtiter plate assay. ResultsAll together 60 Pseudomonas aeruginosa were isolated from a total of 275 isolates. The antibiotic susceptibility profile showed that more than 50% of isolates were non-susceptible among the tested antibiotics and shifting of antibiotic choice to piperacillin-tazobactam from traditional amikacin, ciprofloxacin and imipenem. The weak agreement of Kappa statistics indicates that biofilm procurement from the tube method and microtiter plate assay was insignificant. Approximately 25% of P. aeruginosa isolates were biofilm producers and there was no relation between biofilm production and antibiotic susceptibility patterns (χ2 = 0.587). ConclusionPseudomonas aeruginosa is a common isolate from burn wound infections. There is a shifting in antibiotic choice and more than half of the isolates were antibiotic resistant; however, no relation between biofilm formation and multidrug resistant profile of isolates was found.