RESUMO
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.
Assuntos
Úlcera da Perna , Staphylococcus aureus Resistente à Meticilina , Úlcera Varicosa , Humanos , Bandagens , Úlcera Varicosa/tratamento farmacológico , Cicatrização , Resultado do Tratamento , Úlcera da Perna/terapiaRESUMO
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.
Assuntos
Bacteriófagos , Queimaduras , Quitosana , Infecções por Klebsiella , Infecção dos Ferimentos , Ratos , Animais , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Antibacterianos , Biofilmes , Infecção dos Ferimentos/tratamento farmacológico , Infecção dos Ferimentos/microbiologia , Klebsiella pneumoniae , Géis , Queimaduras/tratamento farmacológico , Quitosana/farmacologiaRESUMO
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.
Assuntos
Bacteriófagos , Terapia por Fagos , Animais , Bacteriófagos/fisiologia , Citocinas , Farmacorresistência Bacteriana Múltipla , Klebsiella pneumoniae , RatosRESUMO
The rise in multi-drug resistant bacteria and the inability to develop novel antibacterial agents limits our arsenal against infectious diseases. Antibiotic resistance is a global issue requiring an immediate solution, including the development of new antibiotic molecules and other alternative modes of therapy. This article highlights the mechanism of bacteriophage treatment that makes it a real solution for multidrug-resistant infectious diseases. Several case reports identified phage therapy as a potential solution to the emerging challenge of multi-drug resistance. Bacteriophages, unlike antibiotics, have special features, such as host specificity and do not impact other commensals. A new outlook has also arisen with recent advancements in the understanding of phage immunobiology, where phages are repurposed against both bacterial and viral infections. Thus, the potential possibility of phages in COVID-19 patients with secondary bacterial infections has been briefly elucidated. However, significant obstacles that need to be addressed are to design better clinical studies that may contribute to the widespread use of bacteriophage therapy against multi-drug resistant pathogens. In conclusion, antibacterial agents can be used with bacteriophages, i.e. bacteriophage-antibiotic combination therapy, or they can be administered alone in cases when antibiotics are ineffective.Key points⢠AMR, a consequence of antibiotic generated menace globally, has led to the resurgence of phage therapy as an effective and sustainable solution without any side effects and high specificity against refractory MDR bacterial infections.⢠Bacteriophages have fewer adverse reactions and can thus be used as monotherapy as well as in conjunction with antibiotics.⢠In the context of the COVID-19 pandemic, phage therapy may be a viable option.
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Bacteriófagos , COVID-19 , Antibacterianos/uso terapêutico , Humanos , Pandemias , Estudos Prospectivos , SARS-CoV-2RESUMO
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.
Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Bacteriófagos , Sepse , Infecções por Acinetobacter/terapia , Animais , Antibacterianos , Colistina , CamundongosRESUMO
BACKGROUND: Methicillin resistant Staphylococcus aureus (MRSA) is a major human pathogen associated with nosocomial and community infections. Panton Valentine leukocidin (PVL) is considered one of the important virulence factors of S. aureus responsible for destruction of white blood cells, necrosis and apoptosis and as a marker of community acquired MRSA. This study was aimed to determine the prevalence of PVL genes among MRSA isolates and to check the reliability of PVL as marker of community acquired MRSA isolates from Western Nepal. METHODS: A total of 400 strains of S. aureus were collected from clinical specimens and various units (Operation Theater, Intensive Care Units) of the hospital and 139 of these had been confirmed as MRSA by previous study. Multiplex PCR was used to detect mecA and PVL genes. Clinical data as well as antimicrobial susceptibility data was analyzed and compared among PVL positive and negative MRSA isolates. RESULTS: Out of 139 MRSA isolates, 79 (56.8 %) were PVL positive. The majority of the community acquired MRSA (90.4 %) were PVL positive (Positive predictive value: 94.9 % and negative predictive value: 86.6 %), while PVL was detected only in 4 (7.1 %) hospital associated MRSA strains. None of the MRSA isolates from hospital environment was found positive for the PVL genes. The majority of the PVL positive strains (75.5 %) were isolated from pus samples. Antibiotic resistance among PVL negative MRSA isolates was found higher as compared to PVL positive MRSA. CONCLUSION: Our study showed high prevalence of PVL among community acquired MRSA isolates. Absence of PVL among MRSA isolates from hospital environment indicates its poor association with hospital acquired MRSA and therefore, PVL may be used a marker for community acquired MRSA. This is first study from Nepal, to test PVL among MRSA isolates from hospital environment.
Assuntos
Toxinas Bacterianas/genética , Exotoxinas/genética , Leucocidinas/genética , Staphylococcus aureus Resistente à Meticilina/genética , Proteínas de Bactérias/genética , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana Múltipla/genética , Hospitais , Humanos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Testes de Sensibilidade Microbiana , Nepal/epidemiologia , Proteínas de Ligação às Penicilinas/genética , Estudos Prospectivos , Reprodutibilidade dos Testes , Infecções Estafilocócicas/epidemiologia , Fatores de Virulência/genéticaRESUMO
BACKGROUND & OBJECTIVES: Reduction of viraemia in patients with chronic hepatitis B virus (HBV) infection using nucleoside/nucleotide analogues reduces fatal liver disease-related events, but development of resistance in virus presents serious clinical challenge. Therefore, comparative evaluation of prolonged antiviral monotherapy and combination therapies was prospectively studied to assess their influence on viral suppression, rapidity of response, development of drug resistance and surfacing mutants in chronic liver disease (CLD) patients. METHODS: A total of 158 (62eAg-ve) chronic hepatitis B patients were prospectively studied for 24 months. Final analysis was performed on patients treated with lamivudine (LAM, n = 28), adefovirdipivoxil (ADV, n = 24), tenofovir disoproxil fumarate (TDF, n = 26), entecavir (ETV, n = 25), LAM + ADV (n = 28) and LAM + TDF (n = 27). Quantitative hepatitis B virus DNA was detected using real-time polymerase chain reaction. Multiple comparisons among drugs and genotypic mutations were analyzed. RESULTS: Progressive biochemical and virological response were noted with all the regimens at 24 months except LAM and ADV which were associated with viral breakthrough (VBT) in 46.4 and 25 per cent, respectively. Mutations: rtM204V (39.3%), M204V+L180M (10.7%) while rtA181V (8.1%) and rtN236T (8.3%) were observed with LAM and ADV regimen, respectively. LAM + ADV combination therapy revealed VBT in seven per cent of the cases without mutations whereas TDF, ETV and LAM + TDF therapies neither showed VBT nor mutations. INTERPRETATION & CONCLUSIONS: LAM was the least potent drug among all therapeutic options followed by ADV. TDF and ETV were genetically stable antivirals with a strong efficacy. Among newer combination therapies, LAM + TDF revealed more efficacy in virological remission and acted as a profound genetic barrier on long term. Hence, newer generation molecules (TDF, ETV) and effective combination therapy should be a certain choice.
Assuntos
Farmacorresistência Viral/genética , Guanina/análogos & derivados , Vírus da Hepatite B/efeitos dos fármacos , Hepatite B Crônica/tratamento farmacológico , Tenofovir/administração & dosagem , Adenina/administração & dosagem , Adenina/análogos & derivados , Adulto , Combinação de Medicamentos , Farmacorresistência Viral/efeitos dos fármacos , Feminino , Guanina/administração & dosagem , Vírus da Hepatite B/patogenicidade , Hepatite B Crônica/genética , Hepatite B Crônica/virologia , Humanos , Lamivudina/administração & dosagem , Masculino , Pessoa de Meia-Idade , Mutação , Organofosfonatos/administração & dosagem , Projetos PilotoRESUMO
BACKGROUND & OBJECTIVES: Methicillin resistant Staphylococcus aureus (MRSA) are the commonest cause of osteomyelitis. The aim of this study was to evaluate the role of an alternative therapy i.e. application of S. aureus specific bacteriophages in cases of osteomyelitis caused by MRSA in animal model. METHODS: Twenty two rabbits were included in this study. The first two rabbits were used to test the safety of phage cocktail while the remaining 20 rabbits were divided into three groups; group A (n=4) to assess the establishment of osteomyelitis; group B (n=4) osteomyelitis developed but therapy started only after six weeks; and group C (n=12) osteomyelitis developed and therapy started after three weeks. Groups B and C rabbits were treated with four doses of cocktail of seven virulent bacteriophages at the interval of 48 h. Comparison between three groups was made on the basis of observation of clinical, radiological, microbiological, and histopathological examinations. RESULTS: Experimental group rabbits recovered from the illness in the subsequent two weeks of the therapy. Appetite and activity of the rabbits improved, local oedema, erythema and induration subsided. There were minimal changes associated with osteomyelitis in X-ray and histopathology also showed no signs of infection with new bone formation. Control B group rabbits also recovered well from the infection. INTERPRETATION & CONCLUSIONS: The present study shows a potential of phage therapy to treat difficult infections caused by multidrug resistant bacteria.
Assuntos
Osteomielite/terapia , Terapia por Fagos , Infecções Estafilocócicas/terapia , Animais , Bacteriófagos , Modelos Animais de Doenças , Humanos , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Osteomielite/diagnóstico por imagem , Osteomielite/microbiologia , Coelhos , Infecções Estafilocócicas/microbiologia , Resultado do TratamentoRESUMO
Metronidazole (MZ) and levofloxacin (LF) are widely employed for treatment of periodontitis, but high oral dose and resistance development after long-term oral administration limit their use. The aim of this study was to alleviate shortcomings in the treatment of periodontitis by fabrication of intrapocket, biodegradable films of chitosan (CS) loaded with MZ and LF meant for inserting into periodontal pockets to treat infections. The films were developed by solvent casting technique using propylene glycol as plasticizer and glutaraldehyde as crosslinking agent. Their physical characteristics, such as drug content, surface pH, swelling index, and folding endurance, exhibited results within limit. Further, FTIR and DSC studies revealed stability of films and compatibility between drugs and excipients. SEM images of films showed the presence of free drug particles on the surface causing burst effect. In vitro release in McIlvaine buffer pH 6.6 was of sustained nature assisted by the burst effect. CS and crosslinking agent concentrations negatively affected drug release and positively affected T90 (time for releasing 90% of the drug) due to altered matrix density. In contrast, the plasticizer concentration increases membrane permeability and hence increased drug release, lowering T90. Crosslinked films demonstrated sustained release up to 7 days. The antibacterial efficacy of films was tested on Staphylococcus aureus and Escherichia coli, indicating good antibacterial activity. Clinical trials on patients proved the therapeutic efficacy of the films by a significant (p < 0.05) decrease in the clinical markers of periodontitis, i.e. gingival index, plaque index and pocket depth. Conclusively, the films of MZ and LF were successful tools for the management of periodontitis.
Assuntos
Quitosana/química , Levofloxacino/química , Levofloxacino/uso terapêutico , Metronidazol/química , Metronidazol/uso terapêutico , Periodontite/tratamento farmacológico , Adulto , Antibacterianos/química , Antibacterianos/uso terapêutico , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos , Escherichia coli/efeitos dos fármacos , Excipientes/química , Glutaral/química , Humanos , Pessoa de Meia-Idade , Bolsa Periodontal/microbiologia , Plastificantes/química , Método Simples-Cego , Staphylococcus aureus/efeitos dos fármacos , Adulto JovemRESUMO
BACKGROUND: Mallotus philippinensis Muell. Arg (MP, Euphorbiaceae) are widely distributed perennial shrub or small tree in tropical and subtropical region in outer Himalayas regions. Since, Mallotus philippinensis have been shown to have a number of medicinal values. Hence our present study was to investigate the healing potential of fruit extract in rat wound models. METHODS: The study includes acute toxicity and wound healing potential of 50% ethanol extract of MP fruit glandular hair (MPE). MPE (200 mg/kg) was administered orally, once daily for 10 days (incision and dead space wound) and 22 days (excision wound). MPE was found safe when given to rats upto 10 times of optimal effective dose. Wound breaking strength (WBS) in Incision wound and rate of contraction, period of epithelization and scar area in Excision wound were evaluated. Granulation tissue free radicals (nitric oxide and lipid peroxidation), antioxidants (catalase, superoxide dismutase, and reduced glutathione), acute inflammatory marker (myeloperoxidase), connective tissue markers (hydroxyproline, hexosamine, and hexuronic acid), and deep connective tissue histology were studied in Dead space wound. RESULTS: MPE significantly increased WBS and enhanced wound contraction, and decreased both epithelization period and scar area compared with control group. MPE was found to decrease free radicals (50.8 to 55.2%, P<0.001) and myeloperoxidase (44.0%, P<0.001) but enhanced antioxidants (41.1 to 54.5%, P<0.05 to P<0.001) and connective tissue markers (39.5 to 67.3%, P<0.05 to P<0.01). Histopathological evaluation revealed more density of collagen formation with minimal inflammatory cells in deeper tissues. CONCLUSION: Thus, the study revealed Mallotus philippinensis fruit hair extract, safe and effective in wound healing and the healing effects seemed to be due to decrease in free radical generated tissue damage, promoting effects on antioxidant status and faster collagen deposition as evidenced biochemically and histology.
Assuntos
Antioxidantes/uso terapêutico , Mallotus (Planta) , Fitoterapia , Extratos Vegetais/uso terapêutico , Cicatrização/efeitos dos fármacos , Ferimentos Penetrantes/tratamento farmacológico , Animais , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Biomarcadores/metabolismo , Colágeno/metabolismo , Feminino , Radicais Livres/metabolismo , Frutas , Inflamação/tratamento farmacológico , Masculino , Extratos Vegetais/farmacologia , Ratos , Ferimentos Penetrantes/metabolismo , Ferimentos Penetrantes/patologiaRESUMO
This cross-sectional study was done to evaluate diagnostic efficacy of urine nested polymerase chain reaction (PCR) using broad-range 16SrDNA PCR-based amplification, followed by restriction analysis and sequencing in neonatal septicemia. The study included 50 babies; 48% had vaginal delivery, 46% were preterm, 20% had a history of prolonged rupture of membranes and 56% were low birth weight (≤2500 g). Clinical presentations were lethargy (96%), respiratory distress (80%) and bleeding diathesis (16%). Absolute neutrophil count <1800/mm(3) was observed in 60%, and positive C-reactive protein in 46%. Thirty neonates had positive blood culture, and Klebsiella pneumoniae (22%) was the predominant organism. Nested urine PCR was positive in 38 (76%) and detected bacterial DNA in 8 neonates with negative blood cultures. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of nested PCR were 100, 60, 78.9, 100 and 84%, respectively, compared with blood culture. Nested PCR can detect most bacteria in single assay and identify unusual and unexpected causal agents.
Assuntos
Proteína C-Reativa/análise , Reação em Cadeia da Polimerase/métodos , RNA Ribossômico 16S/análise , Sepse/diagnóstico , Sepse/urina , Urina/microbiologia , Estudos Transversais , DNA/análise , DNA Bacteriano , Feminino , Genes de RNAr/genética , Humanos , Recém-Nascido , Klebsiella pneumoniae/isolamento & purificação , Contagem de Leucócitos , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Sepse/microbiologia , Análise de Sequência de DNA , Staphylococcus aureus/isolamento & purificaçãoRESUMO
Salmonella enterica serovar Typhi faces several environmental stresses while going through the stomach (acidic pH) to the small intestine (basic pH) and intracellularly in macrophages (acidic pH) in humans. The acidic pH followed by alkaline pH in the small intestine might be responsible for expression of certain stress-induced genes, resulting in not only better survival but also induction of multiplication and invasion of the bacterium in the small intestine. Based on this hypothesis, we developed a process wherein we exposed the blood, urine, and stool specimens from 90 acute typhoid fever patients and 36 chronic typhoid carriers to acidic pH to see the effect on isolation rate of S. Typhi. About 5 g of freshly passed unpreserved stool, a centrifuged deposit of 15 ml of urine, and 5 ml of blood clot were subjected to 5 ml of Luria-Bertani (LB) broth (pH 3.5) for 20 min, followed by enrichment in bile broth-selenite F broth. When the combined isolation from all 3 specimens, i.e., blood, urine, and stool, after acid exposure was considered, a total of 77.7% of the acute typhoid patients were observed to be positive for the isolation of the S. Typhi serotype, compared to 8.8% by the conventional method. Similarly, 42% (15/36) of chronic carriers yielded positive for S. Typhi growth after acid exposure, compared to 5.5% (2/36) by the conventional method. It therefore can be concluded that acid shock triggers the multiplication of the bacteria, resulting in better isolation rates from blood clot, stool, and urine specimens.
Assuntos
Ácidos/metabolismo , Portador Sadio/microbiologia , Salmonella typhi/efeitos dos fármacos , Salmonella typhi/crescimento & desenvolvimento , Febre Tifoide/microbiologia , Sangue/microbiologia , Portador Sadio/diagnóstico , Fezes/microbiologia , Humanos , Concentração de Íons de Hidrogênio , Salmonella typhi/isolamento & purificação , Estresse Fisiológico , Febre Tifoide/diagnóstico , Urina/microbiologiaRESUMO
Mallotus philippinensis is an important source of molecules with strong antioxidant activity widely used medicinal plant. Previous studies have highlighted their anticestodal, antibacterial, wound healing activities, and so forth. So, present investigation was designed to evaluate the total antioxidant activity and radical scavenging effect of 50% ethanol fruit glandular hair extract (MPE) and its role on Human Erythrocytes. MPE was tested for phytochemical test followed by its HPLC analysis. Standard antioxidant assays like DPPH, ABTS, hydroxyl, superoxide radical, nitric oxide, and lipid peroxidation assay were determined along with total phenolic and flavonoids content. Results showed that MPE contains the presence of various phytochemicals, with high total phenolic and flavonoid content. HPLC analysis showed the presence of rottlerin, a polyphenolic compound in a very rich quantity. MPE exhibits significant strong scavenging activity on DPPH and ABTS assay. Reducing power showed dose dependent increase in concentration absorption compared to standard, Quercetin. Superoxide, hydroxyl radical, lipid peroxidation, nitric oxide assay showed a comparable scavenging activity compared to its standard. Our finding further provides evidence that Mallotus fruit extract is a potential natural source of antioxidants which have a protective role on human Erythrocytes exhibiting minimum hemolytic activity and this justified its uses in folklore medicines.
Assuntos
Antioxidantes/farmacologia , Eritrócitos/efeitos dos fármacos , Sequestradores de Radicais Livres/farmacologia , Frutas/química , Mallotus (Planta)/química , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Acetofenonas/farmacologia , Benzopiranos/farmacologia , Benzotiazóis/metabolismo , Compostos de Bifenilo/metabolismo , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Hemólise/efeitos dos fármacos , Humanos , Radical Hidroxila , Peroxidação de Lipídeos/efeitos dos fármacos , Óxido Nítrico/metabolismo , Oxirredução/efeitos dos fármacos , Compostos Fitoquímicos/farmacologia , Picratos/metabolismo , Padrões de Referência , Ácidos Sulfônicos/metabolismoRESUMO
Antimicrobial screening of several novel 4-thiazolidinones with benzothiazole moiety has been performed. These compounds were evaluated for antimicrobial activity against a panel of bacterial and fungal strains. The strains were treated with these benzothiazole derivatives at varying concentrations, and MIC's were calculated. Structures of these compounds have been determined by spectroscopic studies viz., FT-IR, 1H NMR, 13C NMR and elemental analysis. Significant antimicrobial activity was observed for some members of the series, and compounds viz. 3-(4-(benzo[d]thiazol-2-yl) phenyl-2-(4-methoxyphenyl)thiazolidin-4-one and 3-(4-(benzo[d]thiazol-2-yl)phenyl)-2-(4-hydroxy phenyl)thiazolidin-4-one were found to be the most active against E.coli and C. albicans with MIC values in the range of 15.6-125 microg/ml. Preliminary study of the structure-activity relationship revealed that electron donating groups associated with thiazolidine bearing benzothiazole rings had a great effect on the antimicrobial activity of these compounds and contributes positively for the action. DNA cleavage experiments gave valuable hints with supporting evidence for describing the mechanism of action and hence showed a good correlation between their calculated MIC's and its lethality.
Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Benzotiazóis/farmacologia , DNA Bacteriano/efeitos dos fármacos , Tiazolidinas/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Antifúngicos/síntese química , Antifúngicos/química , Benzotiazóis/síntese química , Benzotiazóis/química , Candida/efeitos dos fármacos , DNA Circular/efeitos dos fármacos , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Avaliação Pré-Clínica de Medicamentos , Eletroforese em Gel de Ágar , Sequestradores de Radicais Livres/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Tiazolidinas/síntese química , Tiazolidinas/químicaRESUMO
OBJECTIVE: The colistin-resistant Klebsiella pneumoniae causes complicated Urinary Tract Infections (UTIs). Of them, 73% of strains of K. pneumoniae formed moderate to strong biofilm. Multidrug-resistant (MDR)/Pandrug-resistant (PDR) bacteria causing UTIs are very challenging to conventional antibiotic therapy. However, bacteriophages may be a promising alternative as they easily disrupt the biofilm and act on receptors unrelated to antibiotic resistance mechanisms. This preclinical study evaluated the efficacy of a phage cocktail with different routes and dosages (in quantity and frequency) to eradicate the K. pneumoniae-associated UTI in the mice model. METHODS: The three lytic phages with the broadest spectrum activity (ΦKpnBHU1, ΦKpnBHU2, and ΦKpnBHU3) were meticulously characterized using SEM and sequencing. The cocktails were administered to mice through urethral, rectal, subcutaneous, and oral routes after establishing the UTI with 1â¯×â¯108 colony-forming unit/mouse (CFU/mouse) of K. pneumoniae (KpnBHU09) resistant to both the drugs carbapenem and colistin. The efficacy of different routes with varying dosages and frequency of administration was thoroughly optimized. RESULTS: We observed that two doses of a phage cocktail containing 1â¯×â¯105 Plaque-Forming Unit (PFU/mouse) and a single dose of 1â¯×â¯109 PFU/mouse per urethra could eradicate KpnBHU09. Intriguingly, the noninvasive administration through oral and rectal routes required higher concentration and many dosages of phages to eliminate KpnBHU09 at any stage of acute UTI. The subcutaneous route was found unsatisfactory in curing the infection. CONCLUSION: Bacteriophage cocktails administered through transurethral, oral, and rectal routes may cure UTIs.
RESUMO
The emergence of multidrug-resistant mycobacterial strains is a significant crisis that has led to higher treatment failure rates and more toxic and expensive medications for tuberculosis (TB). The urgent need to develop novel therapeutics has galvanized research interest towards developing alternative antimicrobials such as silver nanoparticles (AgNPs). The current study focused on the anti-mycobacterial activity of green-synthesized AgNPs and its polyethylene glycol encapsulated derivative (PEG-AgNPs) with improved stability using the leaves extract of Clerodendrum serratum. Different characterization methods were used to analyze them. DLS analysis revealed a lower polydispersity index of PEG-AgNPs, suggesting a more uniform size distribution than that of AgNPs. The HR-TEM results revealed that the AgNPs and PEG-AgNPs have predominantly spherical shapes in the size range of 9-35 nm and 15-60 nm, respectively, while positive values of Zeta potential indicate their stability. FTIR-ATR analysis confirmed the presence of functional groups responsible for reducing and capping the bio-reduced AgNPs, whereas the XRD data established its crystalline nature. Impressively, the PEG-AgNPs exhibited maximum inhibitory activity against different Tubercular and Non-Tuberculous Mycobacterium species i.e., Mycobacterium smegmatis, Mycobacterium fortuitum and Mycobacterium marinum, relative to those of AgNPs and Linezolid. The flow cytometry assay showed that the anti-mycobacterial action was mediated by an increase in cell wall permeability. Notably, the results of AFM confirm their ability to inhibit mycobacterial biofilm significantly. We demonstrated the nontoxic nature of these AgNPs, explicated by the absence of hemolytic activity against human RBCs. Overall, the results suggest that PEG-AgNPs could offer a novel therapeutic approach with potential anti-mycobacterial activity and can overcome the limitations of existing TB therapies.
RESUMO
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.
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To aid the clinical diagnosis of typhoid fever in India, where most hospitals and primary health centres have no facilities for culture, we report on the development of a novel and rapid immunodiagnostic kit for the direct detection of Salmonella Typhi--specific IgG antibodies against S. Typhi flagellar H antigen. The disease often does not show a specific clinical picture, and can be confused with other febrile illness such as malaria, dengue fever and Staphylococcus aureus. To overcome the problem of cross reactivity specific epitope of the flagellar H antigen was immobilised on the testing kit strip eliminating chances of cross reactivity and false positive results thereby increasing the specificity of the test. Since the immunodiagnostic kit, uses the flagellar H antigen from bacteria present in our country, the antibodies present in the serum of patients of our country will have maximum binding affinity, enhancing the sensitivity of our test kit. The immunodiagnostic kit on analysis gave a positive result with clinically diagnosed typhoid positive patient serum and negative results were obtained with the sera of clinically diagnosed malaria, abscess of Staphylococcus aureus and Visceral leishmaniasis (Kala-azar) patients.
Assuntos
Antígenos de Bactérias/imunologia , Kit de Reagentes para Diagnóstico , Salmonella typhi/imunologia , Febre Tifoide/diagnóstico , Western Blotting , Reações Cruzadas , Eletroforese em Gel de Poliacrilamida , Epitopos/análise , Epitopos/imunologia , Flagelina/imunologia , Humanos , Soros Imunes , Testes Imunológicos/métodos , Índia , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/imunologia , Malária/diagnóstico , Malária/imunologia , Staphylococcus aureus/imunologia , Febre Tifoide/imunologia , Febre Tifoide/microbiologiaRESUMO
Helicobacter pylori infection stimulates strong local inflammatory and specific IgA antibody production. The influence of antibodies on the bacterial colonization is not clear. Here, we have analysed the association between the mucosal IgA level and IL-1ß in various manifestations of the infection seen endoscopically. Antral biopsies of 57 dyspeptic patients were taken for culture, histology and estimation of mucosal levels of anti-H. pylori IgA and IL-1ß. Mean mucosal IgA level was higher in patients with normal mucosa compared to all other groups and lower IgA level was associated with higher bacterial density. IL-1ß was higher in ulcer patients and suspicious malignancy group as compared to normal group and higher level of IL-1ß was associated with higher grades of metaplasia. Present study indicates that local immunity seems to have a protective role against H. pylori infection and higher level of IL-1ß induced by the pathogen may be associated with metaplasia and carcinogenesis.
RESUMO
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.