A Randomized, Placebo-controlled, Double-blind Clinical Trial of Bacteriophage Cocktails in Chronic Wound Infections.

BACKGROUND: Chronic wounds are prevalent globally at endemic proportions. The common features associated with chronic wounds are prolonged inflammatory phase, infection with multidrug-resistant (MDR) bacteria, and subsequent biofilm formation. The present randomized-controlled trial (RCT) study was undertaken on chronic wounds of ≥6 weeks longer duration using customized phages to evaluate the efficacy and safety of bacteriophage therapy. METHODS: The study was conducted from December 2021 to August 2023. Thirty patients in each of the arms (placebo and bacteriophage) were recruited with chronic wounds. The patients, both arms, received the conventional treatment of wound debridement, local antiseptics, and local and systemic antibiotics at the discretion of the treating surgeon. However, before applying the customized bacteriophage cocktail or placebo, the wound surface was thoroughly washed to remove the residual antiseptics. The phage cocktails or placebo were applied on alternate days. The wounds were evaluated using the Bates-Jensen Wound Assessment Tool for the progress of wound healing. RESULTS: A total of 93.3% of the wound became sterile in 39 days (median sterility time), followed by complete healing by the end of 90 days in the phage group. Contrary to this, 83.3% of those on placebo therapy remained colonized by original bacteria or additional new bacteria without healing for up to 90 days. CONCLUSION: With the well-designed RCT, we could conclude that customized bacteriophage therapy using bacteriophage cocktails will definitely cure the chronic wound, irrespective of age, sex, diabetes status, and infection by MDR bacteria.

Phage therapy: a revolutionary shift in the management of bacterial infections, pioneering new horizons in clinical practice, and reimagining the arsenal against microbial pathogens.

The recent approval of experimental phage therapies by the FDA and other regulatory bodies with expanded access in cases in the United States and other nations caught the attention of the media and the general public, generating enthusiasm for phage therapy. It started to alter the situation so that more medical professionals are willing to use phage therapies with conventional antibiotics. However, more study is required to fully comprehend phage therapy's potential advantages and restrictions, which is still a relatively new field in medicine. It shows promise, nevertheless, as a secure and prosperous substitute for antibiotics when treating bacterial illnesses in animals and humans. Because of their uniqueness, phage disinfection is excellent for ready-to-eat (RTE) foods like milk, vegetables, and meat products. The traditional farm-to-fork method can be used throughout the food chain to employ bacteriophages to prevent food infections at all production stages. Phage therapy improves clinical outcomes in animal models and lowers bacterial burdens in numerous preclinical investigations. The potential of phage resistance and the need to make sure that enough phages are delivered to the infection site are obstacles to employing phages in vivo. However, according to preclinical studies, phages appear to be a promising alternative to antibiotics for treating bacterial infections in vivo. Phage therapy used with compassion (a profound understanding of and empathy for another's suffering) has recently grown with many case reports of supposedly treated patients and clinical trials. This review summarizes the knowledge on the uses of phages in various fields, such as the food industry, preclinical research, and clinical settings. It also includes a list of FDA-approved bacteriophage-based products, commercial phage products, and a global list of companies that use phages for therapeutic purposes.

Bacteriophage entrapped chitosan microgel for the treatment of biofilm-mediated polybacterial infection in burn wounds.

Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) bacteria are most commonly present in burn wound infections. Multidrug resistance (MDR) and biofilm formation make it difficult to treat these infections. Bacteriophages (BPs) are proven as an effective therapy against MDR as well as biofilm-associated wound infections. In the present work, a naturally inspired bacteriophage cocktail loaded chitosan microparticles-laden topical gel has been developed for the effective treatment of these infections. Bacteriophages against MDR S. aureus (BPSAФ1) and P. aeruginosa (BPPAФ1) were isolated and loaded separately and in combination into the chitosan microparticles (BPSAФ1-CHMPs, BPPAФ1-CHMPs, and MBP-CHMPs), which were later incorporated into the SEPINEO™ P 600 gel (BPSAФ1-CHMPs-gel, BPPAФ1-CHMPs-gel, and MBP-CHMPs-gel). BPs were characterized for their morphology, lytic activity, burst size, and hemocompatibility, and BPs belongs to Caudoviricetes class. Furthermore, BPSAФ1-CHMPs, BPPAФ1-CHMPs, and MBP-CHMPs had an average particle size of 1.19 ± 0.11, 1.42 ± 0.21, and 2.84 ± 0.28 µm, respectively, and expressed promising in vitro antibiofilm eradication potency. The ultrasound and photoacoustic imaging in infected burn wounds demonstrated improved wound healing reduced inflammation and increased oxygen saturation following treatment with BPs formulations. The obtained results suggested that the incorporation of the BPs in the MP-gel protected the BPs, sustained the BPs release, and improved the antibacterial activity.

A Bacteriophage-Loaded Microparticle Laden Topical Gel for the Treatment of Multidrug-Resistant Biofilm-Mediated Burn Wound Infection.

Klebsiella pneumoniae is regarded as one of the most profound bacteria isolated from the debilitating injuries caused by burn wounds. In addition, the multidrug resistance (MDR) and biofilm formation make treating burn patients with clinically available antibiotics difficult. Bacteriophage therapy has been proven an effective alternative against biofilm-mediated wound infections caused by MDR bacterial strains. In the current study, the bacteriophage (BPKPФ1) against MDR Klebsiella pneumoniae was isolated and loaded into the chitosan microparticles (CHMPs), which was later incorporated into the Sepineo P 600 to convert into a gel (BPKPФ1-CHMP-gel). BPKPФ1 was characterized for lytic profile, morphological class, and burst size, which revealed that the BPKPФ1 belongs to the family Siphoviridae. Moreover, BPKPФ1 exhibited a narrow host range with 128 PFU/host cell of burst size. The BPKPФ1-loaded CHMPs showed an average particle size of  1.96 ± 0.51 µm, zeta potential 32.16 ± 0.41 mV, and entrapment efficiency in the range of 82.44 ± 1.31%. Further, the in vitro antibacterial and antibiofilm effectiveness of BPKPФ1-CHMPs-gel were examined. The in vivo potential of the BPKPФ1-CHMPs-gel was assessed using a rat model with MDR Klebsiella pneumoniae infected burn wound, which exhibited improved wound contraction (89.22 ± 0.48%) in 28 days with reduced inflammation, in comparison with different controls. Data in hand suggest the potential of bacteriophage therapy to be developed as personalized therapy in case of difficult-to-treat bacterial infections.

A Bacteriophage Microgel Effectively Treats the Multidrug-Resistant Acinetobacter baumannii Bacterial Infections in Burn Wounds.

Multidrug-resistant (MDR) Acinetobacter baumannii (A. baumannii) is one of the major pathogens present in burn wound infections. Biofilm formation makes it further challenging to treat with clinically available antibiotics. In the current work, we isolated the A. baumannii-specific bacteriophages (BPABΦ1), loaded into the chitosan microparticles followed by dispersion in gel, and evaluated therapeutic efficacy against MDR A. baumannii clinical strains. Isolated BPABΦ1 were found to belong to the Corticoviridae family, with burst size 102.12 ± 2.65 PFUs per infected host cell. The BPABΦ1 loaded chitosan microparticles were evaluated for quality attributes viz. size, PDI, surface morphology, in vitro release, etc. The developed formulation exhibited excellent antibiofilm eradication potential in vitro and effective wound healing after topical application.

A novel approach for rapid and sensitive detection of Zika virus utilizing silver nanoislands as SERS platform.

To control the spread of the disease, the Zika virus (ZIKV), a flavivirus infection spread by mosquitoes and common in across the world, needs to be accurately and promptly diagnosed. This endeavour gets challenging when early-stage illnesses have low viral loads. As a result, we have created a biosensor based on surface-enhanced Raman scattering (SERS) for the quick, accurate, and timely diagnosis of the Zika virus. In this study, a glass coverslip was coated with silver nanoislands, which were then utilized as the surface for creating the sensing platform. Silver nanoislands exhibit strong plasmonic activity and good conductive characteristics. It enhances the Raman signals as a result and gives the SERS platform an appropriate surface. The created platform has been applied to Zika virus detection. With a limit of detection (LOD) of 0.11 ng/mL, the constructed sensor exhibits a linear range from 5 ng/mL to 1000 ng/mL. Hence, even at the nanogram scale, this technique may be a major improvement over clinical diagnosis approaches for making proper, precise, and accurate Zika virus detection.

Bacteriophage therapy for Escherichia coli-induced urinary tract infection in rats.

Background: The present study evaluates the efficacy of bacteriophage therapy for urinary tract infection (UTI) in rats. Methods: UTI was established by inoculating Escherichia coli (100 µl) at a concentration of 1.5 × 108 CFU/ml per urethra via a cannula in different groups of rats. For treatment, phage cocktails (200 µl) were administered at varying concentrations of 1 × 108 PFU/ml, 1 × 107 PFU/ml and 1 × 106 PFU/ml. Results: The two doses of phage cocktail at the first two concentrations resulted in the cure of UTI. However, the lowest concentration of the phage cocktail warranted more doses to eradicate the causative bacteria. Conclusion: The quantity, frequency and safety of doses could be optimized in a rodent model using the urethral route.

Antimicrobial resistance is primarily caused by antibiotic overuse and misuse, which results in a decline in the ability of antibiotics to treat infections. Urinary tract infections (UTIs) are common but difficult to treat, as they are frequently caused by multidrug-resistant bacteria. Escherichia coli is a common cause of UTIs. Bacteriophages are a potentially viable alternative for the treatment of bacterial infections, and despite the numerous benefits of using phages as antibacterial therapeutics, there are surprisingly few original research articles based on clinical trials, specifically against UTIs. In this study, the efficiency of a customized bacteriophage cocktail for the treatment of UTIs, with varied doses administered directly into the urinary bladder of rats, was evaluated. At higher concentrations, UTIs were completely eradicated after two doses of the bacteriophage cocktail. However, at lower concentrations, additional doses were required to eradicate the infection. Phage therapy appears to have therapeutic potential, and this study indicates the potential frequency of dosages at appropriate concentrations. Phage therapy was both effective and safe.

Recent advancements in nanotechnology-based bacteriophage delivery strategies against bacterial ocular infections.

Antibiotic resistance is growing as a critical challenge in a variety of disease conditions including ocular infections leading to disastrous effects on the human eyes. Staphylococcus aureus (S. aureus) mediated ocular infections are very common affecting different parts of the eye viz. vitreous chamber, conjunctiva, cornea, anterior and posterior chambers, tear duct, and eyelids. Blepharitis, dacryocystitis, conjunctivitis, keratitis, endophthalmitis, and orbital cellulitis are some of the commonly known ocular infections caused by S. aureus. Some of these infections are so fatal that they could cause bilateral blindness like panophthalmitis and orbital cellulitis, which is caused by methicillin-resistant S. aureus (MRSA) and vancomycin-resistance S. aureus (VRSA). The treatment of S. aureus infections with known antibiotics is becoming gradually difficult because of the development of resistance against multiple antibiotics. Apart from the different combinations and formulation strategies, bacteriophage therapy is growing as an effective alternative to treat such infections. Although the superiority of bacteriophage therapy is well established, yet physical factors (high temperatures, acidic pH, UV-rays, and ionic strength) and pharmaceutical barriers (poor stability, low in-vivo retention, controlled and targeted delivery, immune system neutralization, etc.) have the greatest influence on the viability of phage virions (also phage proteins). A variety of Nanotechnology based formulations such as polymeric nanoparticles, liposomes, dendrimers, nanoemulsions, and nanofibres have been recently reported to overcome the above-mentioned obstacles. In this review, we have compiled all these recent reports and discussed bacteriophage-based nanoformulations techniques for the successful treatment of ocular infections caused by multidrug-resistant S. aureus and other bacteria.

Effect of four-layer dressing on the microbiological profile of venous leg ulcer.

OBJECTIVE: Venous leg ulcer (VLU) is a chronic disease and has periods of exacerbation and remission. Various bandage systems-single-layered, double-layered and multiple-layered with elastic and non-elastic components-have been developed. The requirement for sustained pressure brought about the introduction of the four-layer bandage. We studied the bacteriology of VLUs and the effect of four-layer bandages on their healing. METHOD: Clinical details of all patients, with wound size measurement by gauze piece, wax paper and scale, were recorded. The wounds were initially debrided and photographic records of all patients were maintained. Patients were followed up every week, when the dressings and four-layer bandages were changed. RESULTS: A total of 60 patients were recruited to the study with four patients having bilateral disease and so a total of 64 VLUs were evaluated. Of these, 60 (93.8%) healed completely, one (1.6%) healed partially and three (4.7%) did not heal. After excluding the four VLUs that did not fully heal, 10 (16.7%) had recurrence while 50 (83.3%) had no recurrence in the follow-up period, which lasted for one year. During the first visit (baseline), meticillin-resistant Staphylococcus aureus (MRSA) was isolated in 29 (45.31%) VLUs and Pseudomonas spp. in 20 (31.25%) VLUs. With subsequent dressing, the VLU size decreased and the culture of the VLU was sterile from the third culture onwards in 45 cases. There was a significant correlation (p<0.001) between VLU size and the number of dressings. CONCLUSION: Compression therapy is the mainstay of treatment of VLU, with rapid healing and improvement in bacteriological profile. Compression in the range of 30-40mmHg is the most effective treatment for uncomplicated VLUs with adequate arterial competency.

Bacteriophages Can Make a Difference in Water Quality: Evidence From a Community-Based Study From North India.

Background and objectives Diarrhoea is a preventable and treatable faecal-oral disease. Despite significant inputs from the health and non-health sector in the treatment and prevention of diarrhoea, it remains a significant contributor to under-five-years children mortality and exerts profound effects on their growth and development. Bacteriophage has the potential to prevent diarrhoea. Bacteriophage status may influence the extent of diarrhoea. The objectives of the study were a) to assess the bacteriophage status and quality of water based on the Most Probable Number (MPN) count in the drinking water of under-five years children, and b) to find the association of the extent of diarrhoea with the bacteriophage status and quality of drinking water of under-five-years children in rural areas of Varanasi. Methods This is a community-based cross-sectional study done in the Chiraigaon community development block in a rural area of Varanasi. Water samples were collected and analysed in the Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi. Results The result of the study was that bacteriophage is present in 118 samples of water, whereas bacteriophage for Escherichia coli (E. coli), Klebsiella, and Vibrio were present in the drinking water of 81.1%, 53.8%, and 25.8% of under-five-years children, respectively. The water quality was highly satisfactory in 41.7% of samples and unsatisfactory in 15.2% of samples (p<0.004). All samples with highly satisfactory water quality had bacteriophages. Diarrhoea was present in 57.14% of samples without bacteriophage and 24.5% in samples with bacteriophage (p<0.01). The unadjusted odds ratio is 4.09. Interpretation and conclusions The odds of diarrhoea are four times higher in the water sample without bacteriophage than in the water sample in which bacteriophage is present. Bacteriophage study in preventing diarrhoea in children under five and health risk assessment call for focus.

Bacterial profile and antibiotic susceptibility pattern of uropathogens causing urinary tract infection in the eastern part of Northern India.

Urinary tract infection (UTI) is a common infectious disease that affects men and women. It is a significant health concern due to multidrug-resistant (MDR) organisms. Therefore, it is necessary to have a current understanding of the antibiotic susceptibility (AS) pattern of uropathogens to manage UTI effectively. Since the bacterial pathogen causing UTI and its AS vary with time and place, the prevailing AS pattern of the causative agents are essential for empirical antibiotic therapy. This study aims to determine the prevalence and AS of uropathogens isolated from UTI patients in the eastern part of Northern India. The study was carried out between November 2018 and December 2019. Clean catch midstream urine samples were collected and processed using standard guidelines for microbiological procedures. Positive microbiological cultures were found in 333 of the 427 patients, where 287 were gram-negative bacteria (GNB), and 46 were gram-positive bacteria (GPB). Females had a higher prevalence of UTI (60.7%) than males (39.3%) (p = 0.00024). The most susceptible age group in females was 18-50 years as compared to males, whereas at the age of 51-80 years and >80 years males were more susceptible than females (p = 0.053). The most prevalent pathogen identified were Escherichia coli (55.0%), followed by Proteus sp. (6.9%), Klebsiella pneumoniae (6.6%), Pseudomonas aeruginosa (6.3%), of which 96.0% were MDR bacteria. The susceptibility pattern of our study also revealed that amikacin, gentamycin and imipenem were the most effective drugs against GNB. In contrast, nitrofurantoin, vancomycin, and chloramphenicol were the most effective drugs against GPB. According tothe findings, MDR pathogens are very much prevalent. Since UTI is one of the most frequent bacterial diseases, proper management necessitates extensive investigation and implementation of antibiotic policy based on AS patterns for a particular region.

SERS based rapid and ultrasensitive detection of Japanese Encephalitis Virus.

Japanese encephalitis (JE) is a mosquito-borne flavivirus infection named Japanese Encephalitis Virus (JEV), prevalent in Asia-pacific countries, requires an accurate and rapid diagnosis to contain the outbreak of the disease. In cases of low viral load in early-stage infections, this task becomes difficult. Therefore, we have developed a surface-enhanced Raman spectroscopy (SERS) based biosensor for rapid, sensitive, and early-stage detection of JE antigen. In this work, silver nanoparticles were deposited over a glass coverslip and used as a substrate for designing the sensing platform. Silver Nanoparticles have good metallic properties and plasmon activity. Therefore, it amplifies the Raman signals and provides a suitable surface for the SERS substrate. The developed platform has been used for the detection of the Japanese encephalitis virus (JEV). The fabricated sensor shows a linear response from 5 ng/mL to 80 ng/mL with a limit of detection (LoD) of ∼7.6 ng/mL. Therefore, this method could be a significant addition to the diagnostic modalities for early, sensitive, and specific diagnoses of JE antigen even at the nanogram level.

Immunological and safety profile of bacteriophage therapy: A pre-clinical study.

AIMS: Numerous pre-clinical and clinical studies have recently demonstrated the significant role of phage therapy in treating multidrug-resistant bacterial infections. However, only a few researchers have focused on monitoring the phage-mediated adverse reactions during phage therapy. The present study aimed to demonstrated the oral acute and sub-acute toxicity of bacteriophages (Klebsiella pneumoniae XDR strain) in Charles Foster rats with special reference to immunological response and adverse effects. METHODS AND RESULTS: Bacteriophages were orally administered in dosages of 1010  PFU/ml and a 1015  PFU/ml to Charles Foster rats as a single dose (in acute toxicity study) and daily dosage for 28 days (in sub-acute toxicity study). One millilitre suspension of bacteriophages was administered through the oral gavage feeding tube. No adverse effect was observed in any of the experimental as well as in the control animals. Furthermore, an insignificant change in food and water intake and body weight was observed throughout the study period compared with the control group rats. On the 28th day of phage administration, blood was collected to estimate haematological, biochemical and cytokines parameters. The data suggested no difference in the haematological, biochemical and cytokine profiles compared to the control group. No significant change in any of the treatment groups could be observed on the gross and histopathological examinations. The cytokines estimated, interleukin-1 beta (IL-1ß), IL-4, IL-6 and IFN-gamma, were found within the normal range during the experiment. CONCLUSIONS: The results concluded that no adverse effect, including the severe detrimental impact on oral administration of high (1010 PFU/ml) and very high dose (1015  PFU/ml) of the bacteriophages cocktail. SIGNIFICANCE AND IMPACT OF STUDY: The high and long-term oral administration of bacteriophages did not induce noticeable immunological response as well.

Evaluation of Bacteriophage Cocktail on Septicemia Caused by Colistin-Resistant Klebsiella pneumoniae in Mice Model.

Objective: The emergence of resistance against last-resort antibiotics, carbapenem and colistin, in Klebsiella pneumoniae has been reported across the globe. Bacteriophage therapy seems to be one of the most promising alternatives. This study aimed to optimize the quantity and frequency of bacteriophage cocktail dosage/s required to eradicate the Klebsiella pneumoniae bacteria in immunocompetent septicemic mice. Methods: The three most active phages ɸKpBHU4, ɸKpBHU7, and ɸKpBHU14 characterized by molecular and TEM analyses were in the form of cocktail and was given intraperitoneally to mice after inducing the septicemia mice model with a constant dose of 8 × 107 colony-forming unit/mouse (CFU/mouse) Klebsiella pneumoniae. After that, the efficacy of the phage cocktail was analyzed at different dosages, that is, in increasing, variable, constant, and repeated dosages. Furthermore, interleukin-6 and endotoxin levels were estimated with variable doses of phage cocktail. Results: We have elucidated that phage therapy is effective against the Klebsiella pneumoniae septicemia mice model and is a promising alternative to antibiotic treatments. Our work delineates that a single dose of phage cocktail with 1 × 105 plaque-forming unit/mouse (PFU/mouse) protects the mice from fatal outcomes at any stage of septicemia. However, a higher phage dosage of 1 × 1012 PFU/mice is fatal when given at the early hours of septicemia, while this high dose is not fatal at the later stages of septicemia. Moreover, multiple repeated dosages are required to eradicate the bacteria from peripheral blood. In addition, the IL-6 levels in the 1 × 105 PFU/mouse group remain lower, but in the 1 × 1012 PFU/mouse group remains high at all points, which were associated with fatal outcomes. Conclusion: Our study showed that the optimized relatively lower and multiple dosages of phage cocktails with the strict monitoring of vitals in clinical settings might cure septicemia caused by MDR bacteria with different severity of infection.

Biological Therapy on Infected Traumatic Wounds: A Case-Control Study.

Background:Traumatic wound is a great challenging issue to surgeons, because of large in size, heavily contaminated, infected and unscenic. Infection proceeded to progressive tissue necrosis, septicemia, organ failure or even death. Majority has polymicrobial infections. Bacteriohage therapy will have revolutionized in the treatment of wound. The present study was planned to evaluate the efficacy of topical bacteriophage therapy on large traumatic wounds in comparison with conventional therapy. Methods:The Study conducted from Sept. 2018 to July 2020. Samples between 12- 60 years was taken into study. Customized bacteriophage applied over the wound after serial debridement in case and conventional dressing in control. Fifty four wounded person met the clinical inclusion criteria; 27 in each group. Wound swab and tissue biopsy was taken for bacterial isolation. Isolated specific phage was applied over the wound on alternate day till the wound become sterile and fit for further definitive management. Results: A significant and rapid improvement was observed in wound healing in cases then control group. Average number of day required for complete granulation of wound and attaining sterility was half in cases then control. The hospital stay of the patients on BT was half (20days) than those on CT (40 days). The financial analysis also favours the BT over CT as only 1/third expenditure incurred in BT group as compared to CT Conclusion:Topical Bacteriophage therapy is efficient, effective to clearing the infection in shorter length of time and cost effective for infected traumatic wounds as compared to conventional dressing.

Ciprofloxacin-Tethered 1,2,3-Triazole Conjugates: New Quinolone Family Compounds to Upgrade Our Antiquated Approach against Bacterial Infections.

A newer ciprofloxacin series containing 1,2,3-triazole conjugates of ciprofloxacin was designed, synthesized, and well characterized using modern analytical techniques by reacting diversified anilines with ciprofloxacin obtained from ciprofloxacin hydrochloride. The newer conjugates were evaluated for their antimicrobial activity against various strains, viz. Staphylococcus aureus (ATCC25923), Enterococcus faecalis (clinical isolate), Staphylococcus epidermidis (ATCC3594), Escherichia coli (ATCC25922), Pseudomonas aeruginosa (ATCC27853), Salmonella typhi (clinical isolate), Salmonella typhimurium (clinical isolate), Acinetobacter baumannii (ATCC19606), Aeromonas hydrophila (ATCC7966), Plesiomonas shigelloides (ATCC14029), and Sphingo biumpaucimobilis (MTCC6362) in vitro. Interestingly, some of the conjugates showed superior antimicrobial activity as compared to the control drug ciprofloxacin. The three compounds 4i, 4j, and 4n showed strong activity with minimum inhibitory concentration (MIC) 0.78 µM, while the compound 4g showed MIC 1.56 µM against S. typhi (clinical). The compound 4a showed good efficacy against S. aureus (ATCC25923) and S. typhi (clinical) with MIC 3.12 µM, while the compound 4b exhibited efficacy with MIC 3.12 µM against S. aureus (ATCC25923) and the control drug ciprofloxacin showed MIC 6.25 µM. Among all of the synthesized compounds, 4e, 4f, 4g, 4h, 4p, 4q, 4t, and 4u displayed less than 20% hemolysis, while the rest of the compounds showed hemolysis in the range of 21-48%. Moreover, the structure of compound 4b was also established by single-crystal X-ray diffraction studies.

Reprofiling of approved drugs against SARS-CoV-2 main protease: an in-silico study.

Given the COVID-19 pandemic, currently, there are many drugs in clinical trials against this virus. Among the excellent drug targets of SARS-CoV-2 are its proteases (Nsp3 and Nsp5) that plays vital role in polyprotein processing giving rise to functional nonstructural proteins, essential for viral replication and survival. Nsp5 (also known as Mpro) hydrolyzes replicase polyprotein (1ab) at eleven different sites. For targeting Mpro, we have employed drug repurposing approach to identify potential inhibitors of SARS-CoV-2 in a shorter time span. Screening of approved drugs through docking reveals Hyaluronic acid and Acarbose among the top hits which are showing strong interactions with catalytic site residues of Mpro. We have also performed docking of drugs Lopinavir, Ribavirin, and Azithromycin on SARS-CoV-2 Mpro. Further, binding of these compounds (Hyaluronic acid, Acarbose, and Lopinavir) is validated by extensive molecular dynamics simulation of 500 ns where these drugs show stable binding with Mpro. We believe that the high-affinity binding of these compounds will help in designing novel strategies for structure-based drug discovery against SARS-CoV-2.Communicated by Ramaswamy H. Sarma.

Evaluation of bacteriophage cocktail on septicaemia caused by colistin-resistant Acinetobacter baumannii in immunocompromised mice model.

Background & objectives: Since the bacterium, Acinetobacter baumannii (AB) has acquired resistance to almost all commercially available antibiotics, the search for alternative treatment options continues to be need of the hour. Bacteriophage therapy seems to be the most promising amongst various proposed alternatives (e.g. antimicrobial peptides, bacteriocin, probiotics, etc.). The present study, therefore, aimed to evaluate the effect of different dosages of specific phages in immunocompromised rodents in a septicaemia model caused by AB mimicking real clinical situations. Methods: The three most active and unique phages (ɸAb4, ɸAb7 and ɸAb14) were selected for this study. A constant dose (100 µl of 108 pfu/ml) of AB was given in all the experiments. Five different sets of experiments were designed: prophylactic administration of phage cocktail in the volume of 100 µl (109 pfu/ml) before and simultaneous with the bacterial challenge; and therapeutic i.e. administration of phage cocktail six, 12 and 24 h after bacterial challenge. Since there were deaths in mice when phage was given 24 h after bacterial challenge, the reduced dosage i.e. 100 µl of 107, 10[6], 105 pfu/ml of phage cocktail was also evaluated. Results: The administration of 100 µl (109 pfu/ml) of phage cocktail after six, 12 and 24 h of the bacterial challenge resulted in the mortality ranging between 20 to 60 per cent. However, no mortality could be observed with simultaneous or prophylactic administration of phages with the bacterial challenge. No mortality was observed with reduced doses of the cocktail (10[6] and10[5] pfu/ml). Interpretation & conclusions: As per the results of this study, it may be concluded that even if patients with acute infections report late to the hospital, a relatively low dose of the phage cocktail may be therapeutically beneficial.

Vitality of Proteinase K in rRTPCR Detection of SARS-CoV2 Bypassing RNA Extraction.

This study aimed to detect the SARS-COV2 viral component directly from inoculated VTM without RNA extraction. Inoculated VTMs of already tested 50 positive and 50 negative samples were divided into three groups. Group I was treated with Proteinase K (PK) followed by 3-step-heat treatment at different temperatures (25°C, 60°C, and 98°C) and stored at 4°C. Group II was directly subjected to 3-step-heat treatment without PK exposure and stored at 4°C. And group III was set-up as standard group; it was processed using Qiagen's column based QIAamp Nucleic Acid kit and the obtained nucleic acids were stored at 4°C. These stored samples were used as a template to execute real-time polymerase chain reaction, and results were noted. Group I demonstrated 96% and 88% sensitivity for N and ORF1ab genes respectively, whereas group II demonstrated 78% and 60% when compared to the results of standard group III. Overall group I showed better results than group II when compared to group III. Thus, in situations where gold-standard reagents are not available, PK exposure and heat treatment can be employed to carry out molecular detection of SARS-CoV2 viral component.