Hemolysin Production Research Articles

The Effect of Aqueous and Alcoholic Extracts of Punica granatum L. Pericarp on Hemolysin Production of several Bacterial species

Four local hemolysin producer bacterial isolates were selected, tow of them gram negative bacteria (Escherichia coli ,Pseudomonas aeruginosa ) and the other two were gram positive bacteria (Staphylococcus aureus , Bacillus cereus ). Minimum inhibitory concentration of the aqueous and alcoholic extracts of Punica granatum L. pericarp were determined towards the four bacterial isolates ,results obtaind showed that MICs of the aqueous extract were 200 mg/ml for E .coli and P. aeruginosa isolates while were 5 mg/ml and 2 mg/ml for B. cereus, S. aureus , respectively The MICs for the ethanolic extract were 50 mg/ml , 20 mg/ml ,1 mg/ml ,0.5 mg/ml for E. coli ,P. aeruginosa ,B. cereus ,S. aureus , respectively. The effect of Sub-MICs of the aqueous and alcoholic extracts on hemolysin production was investigated , both extracts had a suppressing effect on hemolysin production by E. coli ,P. aeruginosa ,while both extract had an inhibitory effect on hemolysin production by S. aureus and B . cereus isolates

Characterization of Candida species isolated from clinical specimens: insights into virulence traits, antifungal resistance and molecular profiles

BackgroundCandida species have emerged as a significant cause of opportunistic infections. Alongside the expression of various virulence factors, the rise of antifungal resistance among Candida species presents a considerable clinical challenge.AimThis study aimed to identify different Candida species isolated from clinical specimens, evaluate their antifungal sensitivity patterns, identify key genes regulating virulence mechanisms using multiplex PCR and to assess any correlation between their virulence profiles and antifungal resistance patterns.MethodA total of 100 Candida spp. was isolated from 630 different clinical specimens and identified to the species level. Their antifungal susceptibility was phenotypically evaluated in accordance with CLSI guidelines using the Vitek-2 Compact System. Virulence markers, including biofilm formation capacity, protease production, melanin production, coagulase production and hemolysin production, were also phenotypically detected. The genetic determinants for biofilm formation and extracellular hydrolytic enzymes were assessed using a multiplex PCR assay.ResultsThe prevalence of Candida spp. was 15.9%, with C. albicans (48%) and C. glabrata (16%) being the most common. C. albicans showed the highest virulence, with strong biofilm formation, and high proteinase and melanin production. Multiplex PCR revealed Hlp in 22.0%, Hwp in 80.0%, Als in 56.0%, and Sap genes in 56.0% of isolates. Virulence genes were more common in C. albicans than in non-albicans Candida (NAC). Resistance patterns significantly correlated with virulence profiles, with notable associations between flucytosine resistance and the presence of Hlp and Hwp genes.ConclusionThe significant correlation between virulent markers such as germination, coagulase, hemolysin production and resistance patterns among different Candida isolates is crucial for predicting the severity and outcomes of Candida infections. This understanding aids in guiding tailored treatment strategies.

Antibiofilm and antivirulence potentials of iodinated fmoc-phenylalanine against Staphylococcus aureus

Staphylococcus aureus poses significant risks to public health due to its ability to form biofilm and produce virulence factors, contributing to the increase in antibiotic resistance and treatment complications. This emphasizes the urgent need for novel antimicrobial controls. Based on the premise that halogenation improves antimicrobial efficacy, this study investigated the ability of halogenated phenylalanine to effectively inhibit S. aureus biofilm formation and virulence activities. Among 29 halogenated compounds, Fmoc-4-iodo-phenylalanine (Fmoc-Iodo-Phe) displayed the highest antibiofilm effect against S. aureus, achieving 94.3 % reduction at 50 μg/mL. Microscopic studies confirmed its ability to prevent and disrupt mature biofilms. At 10 μg/mL, Fmoc-Iodo-Phe markedly inhibited virulence factors, such as cell surface hydrophobicity, hemolysin and slime production. It showed low propensity for resistance development and effectively inhibited biofilms formed by methicillin-resistant S. aureus (MRSA) and S. epidermidis, but was inactive against Gram-negative bacteria. Gene expression analysis complemented by molecular docking suggest that Fmoc-Iodo-Phe could target the AgrA quorum sensing cascade due to strong interactions with key residues at its DNA binding sites. Notably, it was non-cytotoxic in Caenorhabditis elegans model and satisfied drug-likeliness criteria based on ADMET prediction. Therefore, our findings position Fmoc-Iodo-Phe as a promising antimicrobial candidate against S. aureus infections, underscoring its potential as an alternative to traditional antibiotics.

Effect of Growth Conditions on Hemolysin Production from Clinical Isolates of <i>Escherichia Coli</i>

Background: Escherichia coli belongs to the Enterobacteriaceae family and is found in the digestive systems of humans and various animals as normal flora. Objective: This study aims to identify the optimal conditions necessary for the synthesis of hemolysin by E. coli isolated from a variety of clinical contexts. Methods: A total of 120 specimens were collected from different clinical sources in Baghdad Hospitals. Screening for hemolysin production was done by plate and Spectrophotometric methods. Furthermore, many conditions for producing hemolysin from clinical E. coli isolates were investigated including temperature, pH, incubation time, inoculum size, culture medium, and aeration. Results: Six isolates of E. coli exhibited hemolysin production. Optimal conditions for hemolysin production were determined: the temperature was 37 °C with an optical density of 0.931, the pH was 7 with an optical density of 0.976, the incubation period was 24 hours with an optical density of 0.885, 1% inoculum resulting in an optical density of 0.558, brain heart infusion as the best medium with an optical density of 1.697, and a shaker method showing superior results (optical density of 1.235) compared to static aeration (optical density of 0.988). Conclusions: This study identified the optimal conditions necessary for the synthesis of hemolysin by E. coli. By understanding these optimal conditions, researchers may be better equipped to develop strategies for managing and controlling the spread of these pathogenic bacteria.

Phenotypic and genotypic characterization of antimicrobial resistance in Enterococcus species from dairy niches

The present work was carried out to investigate the prevalence of antimicrobial resistance (AMR) in dairy enterococci. Dairy samples comprising of raw milk and traditionally fermented milks were collected from local surrounding areas and a total of 140 enterococci strains were isolated from the dairy samples and further, 104 isolates were tested for antimicrobial susceptibility. The most prevalent resistance was observed against cephalosporins followed by fosfomycin, rifampicin, erythromycin etc. Multi-antibiotic resistance index of the tested isolates ranged from 0.09 to 0.36. Minimum inhibitory concentration testing showed very high cut-offs against erythromycin, tetracycline, cefepime and cefotaxime in certain isolates. Further, Extended Spectrum β-lactamase (ESBL) production tested by double disc synergy method confirmed 9 isolates as ESBL positive along with the presence of blaTEM gene in certain isolates. In addition, AMR genes against aminoglycoside, tetracyclines, macrolides, chloramphenicol along with multi-drug transporter gene (emeA) was also detected in many isolates. The resistant enterococci isolates also showed a high frequency of the presence of mobile genetic elements viz. Transposons (Tn-5397 and Tn-916/Tn-1545 family) and Integrons (intI1, intI3). Finally, virulence traits such as gelatinase and hemolysin production along with gelE and cylA genes was also detected in many of the resistant enterococci isolates. Although, the virulence traits could not be directly correlated with the AMR resistance of the isolates, the results from the study demonstrated the wide prevalence of AMR in dairy enterococci that could greatly contribute to the problem of antimicrobial resistance in the food chain.

Transcriptomic and Biochemical Analysis of the Antimicrobial Mechanism of Lipopeptide Iturin W against Staphylococcus aureus.

Staphylococcus aureus is one of the most serious pathogens threatening food safety and public health. We have previously showed that iturin W exhibited obvious antifungal activity on plant pathogens. In the present study, we found iturin W, especially C14 iturin W, showed strong antimicrobial activity against S. aureus, and the antimicrobial mechanism of C14 iturin W was further investigated by transcriptomic analysis and a related biochemical experiment. The results showed that C14 iturin W can reduce the expression levels of genes associated with the reactive oxygen species (ROS) scavenging enzyme and genes involved in arginine biosynthesis, thus leading to the increase in ROS levels of S. aureus. Furthermore, C14 iturin W can also interfere with proton dynamics, which is crucial for cells to regulate various biological possesses. Therefore, ROS accumulation and change in proton motive force are import ways for C14 iturin W to exert the antimicrobial activity. In addition, C14 iturin W can also reduce the expression levels of genes related to virulence factors and decrease the production of enterotoxins and hemolysins in S. aureus, indicating that C14 iturin W has a good potential in food and pharmaceutical fields to reduce the harm caused by S. aureus in the future.

Actinomycin D reduces virulence factors and biofilms against Aeromonas hydrophila.

Aeromonas hydrophila, a Gram-negative bacterium, is ubiquitously found in many aquatic habitats, causing septicemia in humans and fishes. Attributed to abuse or misuse of conventional antimicrobial drug usage, antimicrobial resistance is at an alarming rise. There is an available alternative strategy to bacterial resistance to antimicrobials, which is inhibition of virulence and pathogenicity employing quorum sensing inhibitors (QSIs). Hence, actinomycin D's effectiveness against A. hydrophila SHAe 115 as a QSI was investigated in decreasing virulence factors and preventing biofilm formation. Actinomycin D, belongs to the QSI combating Pseudomonas aeruginosa PAO1 originally isolated from an entophytic actinomycete (Streptomyces cyaneochromogenes RC1) in Areca catechu L. In the present work, further investigations were carried out to assess the effect of actinomycin D at subminimal inhibitory concentrations (sub-MICs), QS-regulated virulence factors, and biofilm inhibition strategies. Intrinsic properties encompassing inhibition of the production of protease and hemolysin and subsequent activities on biofilm formation and eradication of mature biofilm were established along with weakened swimming and swarming motilities in A. hydrophila SHAe 115. In the Tenebrio molitor survival assay, actinomycin D effectively reduced the virulence and pathogenicity of A. hydrophila, resulting in elimination of mortality. However, the hydrolysate of actinomycin D, 2-hydroxy-4,6-dimethyl-3-oxo-3H-phenoxazine-1,9-dicarboxylic acid (HDPD), had lost the QSI activity in A. hydrophila. Actinomycin D was proved as a viable QSI in lessening A. hydrophila's the virulence and pathogenicity, as evident from our research findings.

Evaluation of Epidemiological Pattern of Candida Species Associated with Candidemia from A Tertiary Care Facility in South India

Candidemia ranks the 4th most prevalence cause of bloodstream infections and stands out as the primary cause of invasive fungal infections among hospitalized patients. Its incidence varies globally from 0.33 to 6.51 episodes per 1000 admissions, representing a major public health burden due to its increasing incidence and high mortality rates. The present research work has been conducted to identify the distribution of Candida species among septicemic patients and to determine the patterns of antifungal susceptibility of Candida species isolates from them in a tertiary care center in South India. Among the 88 Candida isolates, 13 (14.8%) were speciated and identified as C. albicans and 75 (85.2%) were Candida non-albicans. Of them, C. tropicalis (42%) ranks more prevalent. The distribution of virulence factors among 88 Candida isolates revealed that 49 isolates (55.7%) exhibited phospholipase activity, hemolysin production was detected in 68.2% of isolates, biofilm production was demonstrated in 73.9% isolates and coagulase activity was observed in 46.7% isolates. In the present study, Candida species were most sensitive to Amphotericin B (94.3%), which is followed by Caspofungin (93.2%), Voriconazole (92%), Micafungin (90.9%), and the least was observed with Flucytosine (78.4%) and Fluconazole (71.5%). Thus, in order to improve treatment responses, the insights acquired from this research will aid in clinical management and the development of antifungal stewardship recommendations.

Potential antivirulence and antibiofilm activities of sub-MIC of oxacillin against MDR S. aureus isolates: an in-vitro and in-vivo study

BackgroundMulti-drug resistant Staphylococcus aureus is one of the most common causes of nosocomial and community-acquired infections, with high morbidity and mortality. Treatment of such infections is particularly problematic; hence, it is complicated by antibiotic resistance, and there is currently no reliable vaccine. Furthermore, it is well known that S. aureus produces an exceptionally large number of virulence factors that worsen infection. Consequently, the urgent need for anti-virulent agents that inhibit biofilm formation and virulence factors has gained momentum. Therefore, we focused our attention on an already-approved antibiotic and explored whether changing the dosage would still result in the intended anti-virulence effect.MethodsIn the present study, we determined the antibiotic resistance patterns and the MICs of oxacillin against 70 MDR S. aureus isolates. We also investigated the effect of sub-MICs of oxacillin (at 1/4 and 1/8 MICs) on biofilm formation using the crystal violet assay, the phenol-sulphuric acid method, and confocal laser scanning microscopy (CLSM). We examined the effect of sub-MICs on virulence factors and bacterial morphology using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and electron microscopy, respectively. Moreover, we studied the effect of sub-MICs of oxacillin (OX) in-vivo using a wound infection model.ResultsOxacillin at 1/2 MIC showed a significant decrease in bacterial viability, while 1/4 and 1/8 MICs had negligible effects on treated bacterial isolates. Treatment of MDR isolates with 1/4 or 1/8 MICs of oxacillin significantly reduced biofilm formation (64% and 40%, respectively). The treated MDR S. aureus with sub-MICs of OX exhibited a dramatic reduction in several virulence factors, including protease, hemolysin, coagulase, and toxic shock syndrome toxin-1 (TSST-1) production. The sub-MICs of OX significantly decreased (P < 0.05) the gene expression of biofilm and virulence-associated genes such as agrA, icaA, coa, and tst. Furthermore, oxacillin at sub-MICs dramatically accelerated wound healing, according to the recorded scoring of histological parameters.ConclusionThe treatment of MDR S. aureus with sub-MICs of oxacillin can help in combating the bacterial resistance and may be considered a promising approach to attenuating the severity of S. aureus infections due to the unique anti-biofilm and anti-virulence activities.

Bioinformatics comparison of hemolysin in different bacteria and experimental evaluation of anti-cancer properties of extracts of some hemolysin-producing bacteria

Cancer is one of the main causes of death in the world. Resistance to anticancer treatments in patients with advanced solid tumors leads to new treatments. Therefore, more alternative anticancer methods have been found over time with greater specificity against tumor cells and with less or no adverse effects on normal cells. Bacterial spores of obligate anaerobes exclusively germinate in the hypoxic/necrotic areas and not in the well oxygenated areas of the body. This unique phenomenon has been exploited in using bacterial spores as a remedy for cancer. Bacterial toxins also play a significant role in either directly killing tumor cells or altering the cellular processes of the tumor cells which ultimately leads to the inhibition and regression of the solid tumor. In the microbial environment, pathogens such as Staphylococcus aureus, Bacillus cereus, or Streptococcus pyogenes produce hemolysin. This protein is used as an anti-cancer protein. To identify the production of hemolysin by bacteria, which can destroy cancer cells more effectively, different bacterial strains were first cultured in blood agar culture medium. The Strains that completely lysed red blood cells, creating transparent zones, were selected for further investigation. Then, to find out which strains have more ability to lyse red blood cells, the qualitative method of halo diameter measurement was used. Also, using quantitative methods, hemolysin strength in microtubes was determined compared to control samples. The results of the hemolysis in the microtube and the qualitative test results showed similar results. In the next step, the cell viability test was performed with the partially purified proteins. Then, bioinformatics studies such as secondary structure investigation, physicochemical properties, pseudo amino acid composition, and molecular docking were performed. The results of molecular docking showed that the hemolysin protein has the highest affinity for the cholesterol of the cytoplasmic membrane, respectively, of Bacillus subtilis, Bacillus cereus, and Staphylococcus aureus bacteria which play a significant role in either directly killing tumor cells or altering the cellular processes of the tumor cells which ultimately leads to the inhibition and regression of the solid tumor.

Virulence Determinants of Acinetobacter baumannii Isolated from Different Infections in Baghdad Hospitals

Acinetobacter baumannii is an essential pathogenic bacteria cause nosocomial infections worldwide. The current work aimed to characterize several virulence factors in Acintobacter baumannii isolated from diverse clinical specimens in Baghdad. Clinical samples including sputum, blood, urine, CSF and wound swabs were collected from patients who were admitted to hospitals in Baghdad. Identification of Acinetobacter baumannii isolates was performed using Vitek 2 system. Phospholipase (plcN) and elastase (lasB) genes were identified using Polymerase chain reaction (PCR) technique. Other virulence factors such as motility, biofilm formation,hemolysin production were screened. Sixty-nine isolates were identified as Acinetobacter baumannii. The isolates were screened for Phospholipase (plcN) and elastase (lasB) production.The results of amplification revealed that out of the total isolates, 18 (26.6%) isolates included both (plcN) and (lasB) genes, 18(26.6%) isolates included only (plcN) and 23(33.3%) isolates have only (lasB). Sixty (86.9%) isolates were positive for biofilm formation, 8 (11.6%) isolates indicated intermediate biofilm producers and 52(75.4%) isolates were weak biofilm producers. Sixty six A.baumannii isolates were motile on Nutrient agar (0.3%). Sixteen isolates were intermediate motile and 50 were highly motile. Positive association was found between the biofilm formation capacity and surface associated motility. Fifty-seven isolates showed hemolysis on Blood agar on the second day of the incubation. Of these, 48 (69.56%) isolates show β –hemolysis and 9 (13.04%) isolates show α-hemolysis,

Citral and triclosan synergistically silence quorum sensing and potentiate antivirulence response in Pseudomonas aeruginosa.

Among the ESKAPE pathogens, Pseudomonas aeruginosa is an extensively notorious superbug that causes difficult-to-treat infections. Since quorum sensing (QS) directly promotes pseudomonal virulence, targeting QS circuits is a promising approach for disarming phenotypic virulence. Hence, this study scrutinizes the anti-QS, antivirulence, and anti-biofilm potential of citral (CiT; phytochemical) and triclosan (TcN; disinfectant), alone and in combination, against P. aeruginosa PAO1/PA14. The findings confirmed synergism between CiT and TcN and revealed their quorum quenching (QQ) potential. At sub-inhibitory levels, CiT-TcN combination significantly impeded pyocyanin, total bacterial protease, hemolysin, and pyochelin production alongside inhibiting biofilm formation in P. aeruginosa. Moreover, the QQ and antivirulence potential of CiT and TcN was positively correlated by molecular docking studies that predicted strong associations of the drugs with QS receptors of P. aeruginosa. Collectively, the study identifies CiT-TcN as an effective drug combination that harbors QQ, antivirulence, and anti-biofilm prospects against P. aeruginosa.

Isolation and diagnosis of Staphylococcus aureus from wounds and detection of some virulence factors

The current study aimed to isolate and diagnose S. aureus, test its antibiotic susceptibility, and detect some virulence factors. 150 Clinical samples were collected from Kirkuk Hospital in Kirkuk city for the period from December 2023 to March 2024 from patients who were admitted and hospitalized after consulting the specialist doctor and referring him to the laboratory. Colonies of S. aureus were diagnosed based on the culturing characteristics of the colonies growing on mannitol salt agar medium and blood agar media and incubated at 37 0C for 24 hrs. The results showed that 47 (31.3%) of the samples showed bacterial growth. On the other hand, the results showed that S. aureus was highly resistant to Benzylpenicillin (81.8%), while it was very sensitive to both Nitrofurantion and Gentamicin (90.9%). A DNase test was conducted for clinical isolates of S. aureus, which were isolated from burns and wounds, and the results were 100% in terms of the susceptibility of S. aureus isolates to DNase results. The ability of 47 isolates of S. aureus to produce hemolysin was tested by culturing the bacteria on blood agar medium. The ratios of S. aureus isolates to haemolysin production varied, as evidenced by the data, with 39 (82.98%) isolates exhibiting complete hemolysis. It is concluded from the current study that S. aureus that was isolated from wounds was highly resistant to antibiotics and had dangerous harmful factors that increased the bacterial level in infections.

Dencichine attenuates the virulence of Fusobacterium nucleatum by targeting hydrogen sulfide-producing enzyme.

Oral opportunistic pathogen Fusobacterium nucleatum can participate in various disease processes through the metabolite hydrogen sulfide, such as halitosis and colorectal cancer. The object of this study is to identify inhibitor capable of suppressing Fn1220, which is the principal hydrogen sulfide-producing enzyme in F. nucleatum. Through this inhibition, we aim to reduce the hydrogen sulfide production of F. nucleatum, consequently diminishing its virulence. Employing molecular docking techniques for inhibitor screening, we identified dencichine as the monomeric compound from Chinese medicine exhibiting the lowest binding energy to Fn1220 among a set of 27,045 candidates, and evaluated in vitro the ability of dencichine to inhibit hydrogen sulfide production using bismuth chloride method. Additionally, we investigated its impact on key virulence factors, including biofilm formation, hemolysis, and adhesion factors of F. nucleatum, using the crystalline violet method, sheep blood method, and RT-qPCR, respectively. Furthermore, we assessed the influence of dencichine on the lifespan of Caenorhabditis elegans. Results showed that dencichine was a suitable inhibitor of the Fn1220 of F. nucleatum, which significantly inhibited the production of virulence factors, e.g., biofilm, hemolysin, FadA, and Fap2 of F. nucleatum and improved the survival of C. elegans. We successfully identified the inhibitor of the enzyme Fn1220, dencichine, which inhibited the production of hydrogen sulfide and attenuated the virulence of F. nucleatum and holds promise as a potential therapeutic avenue for addressing oral diseases, e.g., halitosis in the future.

Overview of Proteus mirabilis pathogenicity and virulence. Insights into the role of metals.

Proteus mirabilis is a Gram-negative bacterium with exclusive molecular and biological features. It is a versatile pathogen acclaimed for its distinct urease production, swarming behavior, and rapid multicellular activity. Clinically, P. mirabilis is a frequent pathogen of the human urinary system where it causes urinary tract infections (UTIs) and catheter-associated urinary tract infections (CAUTIs). This review explores the epidemiology, risk factors, clinical manifestations, and treatment of P. mirabilis infections, emphasizing its association with UTIs. The bacterium's genome analysis revealed the presence of resistance genes against commonly used antibiotics, an antibiotic-resistant phenotype that poses a serious clinical challenge. Particularly, the emergence of extended-spectrum β-lactamases (ESBLs) and carbapenemases resistant P. mirabilis strains. On a molecular level, P. mirabilis possesses a wide array of virulence factors including the production of fimbriae, urease, hemolysins, metallophores, and biofilm formation. This review thoroughly tackles a substantial gap in understanding the role of metallophores in shaping the virulence factors of P. mirabilis virulence. Siderophores, iron metal chelating and transporting metallophores, particularly contribute to the complex pathogenic strategies, displaying a potential target for therapeutic intervention.

الكشف عن بعض عوامل الضراوة بين المبيضات المعزولة من المرضى وانتشار جين candidalysin ECE1

المبيضات البيضاء هي مسبب شائع لعدوى الجهاز التنفسي وداء المبيضات الفموي لدى الناس ، ومسببات أمراض الخميرة الانتهازية والأسباب الرئيسية للمرض والوفيات لدى الأشخاص الذين يعانون من نقص المناعة وتسبب التهابات سطحية على الأسطح المخاطية التي تصيب ملايين الأشخاص في جميع أنحاء العالم. كان الهدف الرئيسي من هذه الدراسة هو التحقق من انتشار بعض عوامل الضراوة التي لها القدرة على تكوين الأغشية الحيوية (Biofilm)، والبروتينيز (Proteinase)، وإنتاج الهيمولايسين( Hymolysine) بين عزلات C. albicans التي تشمل انتشار جين Candidalysin (ECE1). تم جمع العينات خلال الفترة من ايار 2022 الى اب 2022 من 280 عينة (مسحة) لمرضى عراقيين من مختلف الاعمار والاجناس غير مكررين كانوا يعانون من داء المبيضات الفموي وامراض الجهاز التنفسي في مستشفيات بغداد (مستشفى مدينه الطب و مستشفى اليرموك التعليمي ومستشفى مدينه الامامين الطبية التعليمية). تم زراعة العينات التي تم جمعها على وسط اكار السابرويد دكستروز (SDA) مضاف اليه كلورامفينيكول كمضاد للبكتيريا بتركيز 10 ميكجم / مل ، وتم حضن الاطباق الملقحة على وسط SDA عند 37 درجة مئوية لمدة تتراوح بين 24-48 ساعة.أظهرت نتائج الاستنبات أن 102 عينة كانت موجبه، منها58 (56.86%) من تجويف الفم و 44 (43.14%) من الجهاز التنفسي، بينما 178 منها كانت سالبة , تم الكشف عن عزلات المبيضات باستخدام الطرق التقليدية والتي تشمل (النمو على وسط HiCrome Candida ، إنتاج الأنبوب الجرثومي Germ tube ، تكوين الابواغ الكلاميديه Clamydospore وتم تأكيد نتئج التعريف باستخدام نضام VITEK-2 بينت النتائج ان من بين 102 عزلة C. albicans هي الاكثر شيوعا بين الانواع بنسبة 68.63 % ثم تلتها C. tropicalis بنسبة %10.78 ثم C. kruzei %5.88 وC. kefyr %5.88 C. parapsilosis % 4.9 بينما كانت C. glabrata % 3.9 وتمثل النسبة الاقل بين الانواع . تم فحص حساسية عزلات المبيضات للأدوية المضادة للفطريات بطريقة انتشار القرص ، والتي أجريت على النحو الموصى به بواسطة(CLSI) M44-A -وثيقة . أظهرت العزلات درجة عالية من الحساسية للأمفوتريسين-ب 93.14% وكلوتريمازول 90.20% ونسياتين 85.92% ،تم التحقق من انتشار جينCandidalysin (ECE1) بين 70 عزلة من C. albicans باستخدام تقنية تفاعل البلمرة المتسلسل PCR ، وأظهرت النتائج أن 41 58.57% تحتوي على جين Ece1 في تجويف الفم والجهاز التنفسي. و 34 عزلة 48.57% من C. albicans كانت منتجة قوية للغشاء الحيوي, بينما 30 عزلة 42.86% عزلة انتجت بروتيناز و 20 عزلة 28.57% عزلة لديها القدرة على تحلل الدم.

Assessment of virulence potential of &lt;i&gt;Escherichia coli&lt;/i&gt; isolated from clinical and non-clinical sources in port Harcourt, Nigeria.

Escherichia coli commonly occurs as a normal flora found in a variety of gastrointestinal tracts. However, certain strains acquire virulence characteristics. Potentially pathogenic species have also been isolated in non-clinical environments.This often raises concerns on the role these environments play in transmission. This study aimed to assess the occurrence of virulence traits in Escherichia coli isolated from non-clinical and clinical sources in Port Harcourt, Nigeria. Two hundred samples from clinical (urine and stool) and non-clinical (soil and poultry) sources were analyzed. 8 isolation, purification and identification of E. coli isolates were performed using standard bacteriological and biochemical tests. Out of the 200 samples collected, 98 isolates (49%) were confirmed as E. coli. Confirmed E. coli isolates were then tested for virulence using standard phenotypic tests (protease, colicin, congo red, hemolysin, haemagglutination, adhesin and mannose resistant/sensitive haemagglutination). E. coli strains from clinical samples displayed a number of virulence traits ranging frombiofilm producing capabilities (53%), congo red binding propensity (24%), colicin (34%), protease (15%) and hemolysin production (4%) compared to their non-clinical counterpart. All samples were negative for haemagglutination. The total virulence prevalence of E. coli was 81%. Clinical samples possessed more virulence traits (71%) than samples from non-clinical sources (29%), with urine having a higher occurrence among the clinical samples (36%). There is need for an in-depth study on virulence attributes of E. coli and ways to control these factors to minimize the rate of spread and the degree of infections.

Analyzing the safety of the parasiticide fungus Mucor circinelloides: first insights on its virulence profile and interactions with the avian gut microbial community.

Parasiticide fungi are considered an accurate, sustainable, and safe solution for the biocontrol of animal gastrointestinal (GI) parasites. This research provides an initial characterization of the virulence of the native parasiticide fungus Mucor circinelloides (FMV-FR1) and an assessment of its impact on birds' gut microbes. The genome of this fungus was sequenced to identify the genes coding for virulence factors. Also, this fungus was checked for the phenotypic expression of proteinase, lecithinase, DNase, gelatinase, hemolysin, and biofilm production. Finally, an in vivo trial was developed based on feeding M. circinelloides spores to laying hens and peacocks three times a week. Bird feces were collected for 3 months, with total genomic DNA being extracted and subjected to long-read 16S and 25S-28S sequencing. Genes coding for an iron permease (FTR1), iron receptors (FOB1 and FOB2), ADP-ribosylation factors (ARFs) (ARF2 and ARF6), and a GTPase (CDC42) were identified in this M. circinelloides genome. Also, this fungus was positive only for lecithinase activity. The field trial revealed a fecal microbiome dominated by Firmicutes and Proteobacteria in laying hens, and Firmicutes and Bacteroidetes in peacocks, whereas the fecal mycobiome of both bird species was mainly composed of Ascomycetes and Basidiomycetes fungi. Bacterial and fungal alpha-diversities did not differ between sampling time points after M. circinelloides administrations (P = 0.62 and P = 0.15, respectively). Although findings from this research suggest the lack of virulence of this M. circinelloides parasiticide isolate, more complementary in vitro and in vivo research is needed to conclude about the safety of its administration to birds, aiming at controlling their GI parasites.IMPORTANCEA previous study revealed that the native Mucor circinelloides isolate (FMV-FR1) can develop parasiticide activity toward coccidia oocysts, one of the most pathogenic GI parasites in birds. However, ensuring its safety for birds is of utmost importance, namely by studying its virulence profile and potential effect on commensal gut microbes. This initial study revealed that although this M. circinelloides isolate had genes coding for four types of virulence factors-iron permease, iron receptors, ADP-ribosylation factors, and GTPase-and only expressed phenotypically the enzyme lecithinase, the administration of its spores to laying hens and peacocks did not interfere with the abundances and diversities of their gut commensal bacteria and fungi. Although overall results suggest the lack of virulence of this M. circinelloides isolate, more complementary research is needed to conclude about the safety of its administration to birds in the scope of parasite biocontrol programs.

Safety attributes of Pseudomonas sp. P26, an environmental microorganism with potential application in contaminated environments

Currently, the selection of non-pathogenic microorganisms that lack clinically relevant antimicrobial resistance is crucial to bioaugmentation strategies. Pseudomonas sp. P26 (P26) is an environmental bacterium of interest due to its ability to remove aromatic compounds from petroleum, but its safety characteristics are still unknown. The study aimed to: a) determine P26 sensitivity to antimicrobials, b) investigate the presence of quinolone and β-lactam resistance genes, c) determine the presence of virulence factors, and d) evaluate the effect of P26 on the viability of Galleria mellonella (an invertebrate animal model). P26 antimicrobial sensitivity was determined in vitro using the Kirby-Bauer agar diffusion method and the VITEK 2 automated system (BioMerieux®). Polymerase Chain Reaction was employed for the investigation of genes associated with quinolone resistance, extended-spectrum β-lactamases, and carbapenemases. Hemolysin and protease production was determined in human blood agar and skimmed-milk agar, respectively. In the in vivo assay, different doses of P26 were injected into Galleria mellonella larvae and their survival was monitored daily. Control larvae injected with Pseudomonas putida KT2440 (a strain considered as safe) and Pseudomonas aeruginosa PA14 (a pathogenic strain) were included. Pseudomonas sp. P26 was susceptible to most evaluated antimicrobials, except for trimethoprim-sulfamethoxazole. No epidemiologically relevant genes associated with quinolone and β-lactam resistance were identified. Hemolysin and protease production was only evidenced in the virulent strain (PA14). Furthermore, the results obtained in the in vivo experiment demonstrated that inocula less than 108 CFU/mL of P26 and P. putida KT2440 did not significantly affect larval survival, whereas larvae injected with the lowest dose of the pathogenic strain P. aeruginosa PA14 experienced instant mortality. The results suggest that Pseudomonas sp. P26 is a safe strain for its application in environmental bioremediation processes. Additional studies will be conducted to ensure the safety of this bacterium against other organisms.

Oral Rinses: Some Kill and Some Cripple Candida albicans

Introduction: Oral healthcare professionals play a crucial role in guiding patients toward evidence-based choices among the many available oral rinses. In this study, we explored how specific oral rinse formulations affect the viability and modulate critical virulence traits of the opportunistic fungal pathogen Candida albicans. Materials and Methods: We assessed the effects of these oral rinses on the production of germ tube, production of phospholipase and hemolysin, as well as biofilm formation. Results: We found that oral rinses containing cetylpyridinium chloride (CPC) and chlorhexidine (CHX) showed the greatest fungicidal activity with the lowest minimum fungicidal concentrations (0.38% and 0.78%, respectively). Oral rinses based on zinc chloride and sodium fluoride with Miswak bark extract (MIS) or essential oils (EO) had much lower fungicidal activity (8–16 times lower) compared to CHX and CPC. However, they had a significantly greater impact on the virulence traits of C. albicans. They reduced germ tube production by 86–89% (vs. 42% for CHX and 29% for CPC), completely inhibited phospholipase and hemolysin production, and together with the CPC-based oral rinse, exerted the greatest reductions in biofilm formation across all tested concentrations. This was in contrast to both the controls and CHX, which had a minimal effect on biofilm formation. Conclusion: By inhibiting the virulence factors, the oral rinse can have a crippling effect on C. albicans, weakening this opportunistic pathogen and hindering its potential to cause infection.