Development Of Resistant Bacteria Research Articles

Exploring the Interplay of the CRISPR-CAS System with Antibiotic Resistance in Staphylococcus aureus: A Poultry Meat Study from Lahore, Pakistan.

Staphylococcus aureus is one of the major pathogens responsible for causing food poisoning worldwide. The emergence of antibiotic resistance in this bacterium is influenced by various factors. Among them, bacterial acquired defense systems described as clustered regularly interspaced short palindromic repeats (CRISPR)-cas system might be involved in antibiotic resistance development in bacteria. The current study was designed to assess the prevalence of S. aureus and its antibiotic resistance profile and identify the relationship of the CRISPR-cas system with antimicrobial resistance, followed by phylogenetic analysis. Total samples (n = 188) of poultry meat were collected from the poultry bird market of Lahore, Punjab, Pakistan. We used both phenotypic (antibiotic disc diffusion) and genotypic methods (PCR) to identify multi-drug resistant (MDR) strains of S. aureus. Additionally, the role of the CRISPR-Cas system in the isolated MDR S. aureus was also assessed. In addition, real-time quantitative PCR (qRT-PCR) was used to evaluate the association of the CRISPR-cas system with antimicrobial resistance. All of the S. aureus isolates showed 100% resistance against erythromycin, 97.5% were resistant to tetracycline, and 75% were resistant to methicillin. Eleven isolates were MDR in the current study. The CRISPR system was found in all MDR isolates, and fifteen spacers were identified within the CRISPR locus. Furthermore, MDR S. aureus isolates and the standard strain showed higher expression levels of CRISPR-associated genes. The correlation of said system with MDR isolates points to foreign gene acquisition by horizontal transfer. Current knowledge could be utilized to tackle antibiotic-resistant bacteria, mainly S. aureus.

Overcoming microbial resuscitation using stable ultrafine gold nanosystems.

While ultrafine gold nanosystems (UGNs) are being extensively studied for their antimicrobial activities, hitherto, no report is available on their propensity towards mitigating bacterial resuscitation-a potential factor contributing to the antimicrobial resistance. The investigations herein with two categories of gold nanosystems-modulated for their stability and surface accessibility through glutathione capping-have provided insights into overcoming resuscitation. Additionally, the study cautions that even moderate resistance development in bacteria exposed to nanosystems can result in significant cross-resistance against conventional antibiotics.

Effects of Reproductive Hormones in Dairy Farm Animals

Reproductive hormones are utilized in the dairy industry all over the world to improve reproductive effectiveness and, as a result, dairy cow lifespan. The management system of a farm, especially the sort of calving pattern adopted, appears to be a major determinant of variation between countries. The use of pharmaceutical goods like reproductive hormones and antibiotics in animal husbandry, notably dairy production, has been investigated in the recent decade. Consumer concern about food safety, as well as examples of pharmaceutical product misuse, has led to widespread suspicion about using antimicrobials and hormones in industrial agriculture. Hormones aren't involved in the development of resistant bacteria, yet customers are concerned about hormone residues in animal products. One of the most significant aspects of public perception in dairy farming is food safety. Despite their lack of fundamental understanding of the dairy sector, the public is concerned about using reproductive hormones in modern farming, despite the dearth of information regarding their detrimental consequences. On dairy farmed animals, we looked at the effects of oxytocin, progesterone, and prostaglandin. These reproductive hormones are used in milking animals such as cattle, sheep, and goats to boost milk production, reproductive rate, and developmental processes.

Comparative study on the effect of bacteriophage on MDR E.coli from Urinary tract infections

Abstract Introduction/Objective Background: Urinary tract infections (UTIs) associated with urethral catheters are the most common infections during hospitalization. Hospitalization's most common infections are urethral catheter-related UTIs. Bacteriophages infect bacteria exclusively. Phage therapy, especially in Eastern Europe, was widely used before antibiotics. Due to the overuse of antibiotics and the development of resistant bacteria, this therapy approach is regaining popularity. Methods/Case Report Subjects and methods: 2223 UAE-based UTI patients (4–68 years old) were examined. The isolated bacteria were identified biochemically and tested for antimicrobial susceptibility using Mueller-Hinton agar disk diffusion (Kirby Bauer's). TSA (Liofilchem, Italy) kept isolates at 4 °C.for each examination. Tryptic Soy agar (TSA; Liofilchem, Italy) was used to grow one isolated colony overnight at 37 °C. This culture was transferred aseptically to 10 mL of fresh TSB medium and grown overnight at 37 °C to 0.8 optical density. 10 ml CaCl2 in 100 ml LB homogenized EMIRATE sewage water. Overnight homogenates with 9 E. coli isolates—24 hours of 37°C incubation. Samples were centrifuged at 12,000x g for five minutes—a 0.45 mm Millipore (France) filter produced phage lysate. TSA (Liofilchem, Italy) was used as a culture medium, and the centrifuged supernatant as phage suspension for the double-layer method. After 37 °C, plaques were examined. Single-plaque isolations followed. EOP was measured on double-layer agar for bacteria with a clear lysis zone (Adams, 1959). calculated EOP. Phages tested individually. EZ1 and EZ2 were negatively stained with Na-phosphotungstate for morphotype. Results (if a Case Study enter NA) Results: This study found presumptive E. coli colonies in 478 of 2223 (21.5%) samples by plating pre-enriched samples on MacConkey. E. coli B2 and B4 were sensitive to Ciprofloxacin, but most strains were resistant to antibiotics. E. coli B3 was Metronidazole-sensitive. Individual E. coli strains were susceptible to phage infection. Podoviruses were the two phages. 3 log decreased due to E. coli growth. Conclusion This study shows that a single dose of phage can reduce pathogenic MDR E.coli. Phages' high bacterial inactivation efficiency, safety, and prolonged survival, even in urine samples, allow depth studies, especially in vivo studies, to control urinary tract infection and overcome E.coli resistance.

Safety evaluation of the food enzyme subtilisin from the non-genetically modified Bacillus paralicheniformis strain LMG S-30155.

The food enzyme subtilisin (serine endopeptidase, EC 3.4.21.62) is produced with the non-genetically modified microorganism Bacillus paralicheniformis strain LMG S-30155 by ENMEX SA de CV, now part of Kerry Food Ingredients (Cork) Ltd. The food enzyme is intended to be used in oil production, hydrolysis of vegetable/microbial/animal proteins, yeast processing and production of flavouring preparations. The production strain of the food enzyme contains known antimicrobial resistance genes and genes involved in bacitracin biosynthesis. Consequently, it does not fulfil the requirements for the QPS approach to safety assessment. Bacitracin was detected in the food enzyme and the ■■■■■ The presence of bacitracin, a medically important antimicrobial, in the food enzyme represents a risk for the development of resistance in bacteria. Due to the presence of bacitracin, the Panel concluded that the food enzyme subtilisin produced with the non-genetically modified Bacillus paralicheniformis strain LMG S-30155 cannot be considered safe.

The Clinical Significance of Anaerobic Coverage in the Antibiotic Treatment of Aspiration Pneumonia: A Systematic Review and Meta-Analysis

Aspiration pneumonia is increasingly recognised as a common condition. While antibiotics covering anaerobes are thought to be necessary based on old studies reporting anaerobes as causative organisms, recent studies suggest that it may not necessarily benefit prognosis, or even be harmful. Clinical practice should be based on current data reflecting the shift in causative bacteria. The aim of this review was to investigate whether anaerobic coverage is recommended in the treatment of aspiration pneumonia. A systematic review and meta-analysis of studies comparing antibiotics with and without anaerobic coverage in the treatment of aspiration pneumonia was performed. The main outcome studied was mortality. Additional outcomes were resolution of pneumonia, development of resistant bacteria, length of stay, recurrence, and adverse effects. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were followed. From an initial 2523 publications, one randomised control trial and two observational studies were selected. The studies did not show a clear benefit of anaerobic coverage. Upon meta-analysis, there was no benefit of anaerobic coverage in improving mortality (Odds ratio 1.23, 95% CI 0.67-2.25). Studies reporting resolution of pneumonia, length of hospital stay, recurrence of pneumonia, and adverse effects showed no benefit of anaerobic coverage. The development of resistant bacteria was not discussed in these studies. In the current review, there are insufficient data to assess the necessity of anaerobic coverage in the antibiotic treatment of aspiration pneumonia. Further studies are needed to determine which cases require anaerobic coverage, if any.

The using of gamma-octanolactone in the broiler diet: intestinal microbiome

It is known that the inclusion of antibiotics in chicken feed leads to the development of resistance in bacteria. It is for this reason that the search for additives to alternative antibiotics becomes relevant. The ability of gamma-glucanolactone to inhibit various quorum systems (QS) LuxI/LuxR in bacteria has been demonstrated. Based on this, it can be assumed that the use of this substance in the diet will reduce infections in the intestines of poultry and improve the effects of broiler rearing. The aim of this work was to evaluate the microbiome of the iliac intestine of broilers when introducing gammaoctanolactone into the diet.The study was conducted using the sequencing method. Total DNA from samples of intestinal contents was isolated using the FastDNA ® Faecal Extraction Kit. Pair-end sequencing of DNA library amplicons was performed on the Illumina MiSeq Reagent Kit platform using the MiSeq v.2 Reagent Kit (500 cycles) (Illumina, San Diego, California, USA). The inclusion of gamma-octalactone in the diet of broilers at a dosage of 0.05 and 0,20 ml / kg w.m. / day contributes to an increase in the number of representatives of the phylum Firmicutes in the iliac intestine of poultry. The dosage of 0,05 ml / kg w.m. / day of gamma-octanolactone reduced the content of the genus Streptococcus by 4,21%; the dosage of 0,20 ml / kg w.m./ day of gammaoctanolactone increased by 10% representatives of the genera Lactobacillus and Turicibacter, relative to the control.

Evaluation of Local Drug Delivery System Containing 1% (W/V) Chitosan Gel Used as an Adjunct to Scaling and Root Planning in Chronic Periodontitis– A Split Mouth Study

Introduction: Periodontitis is defined as an inflammatory disease of supporting tissues of teeth,In the treatment of periodontitis systemic antibiotics has potential side effect such as the development of resistant bacteria. These limitations can be avoided by application of the antimicrobials in local drug delivery (LDD) systems directly into the periodontal pocket. Natural polymer chitosan which is found in abundance in nature has antibacterial, antiinflammatory properties and is biodegradable and biocompatible. Materials and Method: A randomized controlled split-mouth study was designed. 30 patients were randomly selected.A resorbable chitosan gel of 1% (w/v) was placed in the selected test sites one week after scaling and root planing (SRP). Gel was injected into the periodontal pockets using a blunt cannula till the pocket was completely filled. Periodontal dressing was applied after placement of the gel. The ancillary parameters were assessed. Results: Statistically significant difference was present in mean plaque index scores and modified gingival index scores at 1 month and 3 months from baseline in both the groups as chitosan shows a strong activity in reducing dental plaque against various periodontal pathogens. Statistically significant difference was present in pocket depth between group I and group II at 1 month and 3 month. Statistically, significant difference was present in Relative Attachment Level between group I and group II at 1 months and 3 months. Discussion: In this study Chitosan biopolymer, used in a gel form, (1% w/v) demonstrated the effectiveness for treatment of localized pockets in patients with chronic periodontitis.the results suggest chitosan has its own properties which causes reduction of pocket depth. Conclusion: Chitosan is an effective local drug delivery agent for chronic periodontitis patients.

Bacillus coagulans as an alternative to antibiotics in the performance and control of Salmonella Enteritidis in broilers

The use of antimicrobial growth promoters in broiler feed has been beneficial for improving performance and preventing diseases. However, the indiscriminate use of these products in the feed can result in the development of resistant bacteria, the accumulation of residues in the products, and an imbalance in the microflora of birds. Therefore, it is necessary to evaluate alternatives, such as beneficial microorganisms that improve microbial growth without affecting animal health and product quality. This research aimed to evaluate the supplementation with the probiotic Bacillus coagulans on the performance, carcass characteristics, and health of broilers from seven to 42 days. In total, 720 broilers were used, distributed in a randomized block design with six treatments and eight replicates. The evaluated treatments were as follows: Control ration (RC); PROB1 (Probiotic 400 g/t); PROB2 (Probiotic 400 g/t until 21 days and 200 g/t from 22 to 42 days); RC + antibiotic; RC + Salmonella inoculation; PROB1 + Salmonella inoculation. The treatments did neither influence feed intake, carcass yield, and cuts nor the incidence of injuries to the chest, hock, and footpad. Weight gain and feed conversion were better in birds that received antibiotic or probiotic diets. There was an incidence of Salmonella in the e challenges excreta at 42 days only in the treatment with challenge without adding probiotics. We conclude that the probiotic Bacillus coagulans can be used as an alternative to antibiotics in the diet of broilers as it facilitates similar performance and is efficient in the control of Salmonella Enteritidis.

β-glucan as a promising food additive and immunostimulant in aquaculture industry

Abstract The use of antibiotics in aquatic feed reduces the incidence of disease and enhances growth performance, although it presents harmful effects, such as development of resistant bacteria and accumulation in the natural environment. A variety of immune stimulants including probiotics, prebiotics, synbiotics, phytobiotics, organic acids, nucleotides, antioxidants, microalgae, yeast and enzymes have been used in the aquaculture industry. In recent decades, much attention has been paid to finding a variety of immunostimulants with lower cost which also affect specific and non-specific immunity and improve fish resistance against a wide range of pathogens. These stimulants strengthen the fish’s immune system by increasing the number of phagocytes, lysozyme activity and level of immunoglobulin. The use of immune stimulants as an effective tool to overcome diseases and strengthen the immune system of farmed species, leads to the promotion of cellular and humoral defense mechanisms and increases resistance to infectious diseases. Among these immunostimulants used in aquaculture, β-glucans are of particular importance. Glucans are complex polysaccharide compounds extracted from the cell wall of yeasts and fungi. These compounds can stimulate fish growth, survival, and immune function. Therefore, this review discusses the role and importance of β-glucan as a food additive in aquaculture and examines the impact of these compounds on the growth performance, immunity and biochemical parameters of farmed species.

Does Chlorination Promote Antimicrobial Resistance in Waterborne Pathogens? Mechanistic Insight into Co-Resistance and Its Implication for Public Health.

Chemical agents including chlorine and antibiotics are used extensively to control infectious microorganisms. While antibiotics are mainly used to treat bacterial infections, chlorine is widely used for microbial inactivation in the post-secondary disinfection steps of water treatment. The extensive use of these agents has been acknowledged as a driving force for the expansion of antimicrobial resistance (AMR) and has prompted discourse on their roles in the evolution and proliferation of resistant pathogens in the aquatic milieus. We live in a possible “post-antibiotic” era when resistant microbes spread at startling levels with dire predictions relating to a potential lack of effective therapeutic antibacterial drugs. There have been reports of enhancement of resistance among some waterborne pathogens due to chlorination. In this context, it is pertinent to investigate the various factors and mechanisms underlying the emergence and spread of resistance and the possible association between chlorination and AMR. We, therefore, reflect on the specifics of bacterial resistance development, the mechanisms of intrinsic and acquired resistance with emphasis on their environmental and public health implications, the co-selection for antibiotic resistance due to chlorination, biofilm microbiology, and multidrug efflux activity. In-depth knowledge of the molecular basis of resistance development in bacteria will significantly contribute to the more rational utilization of these biocidal agents and aid in filling identified knowledge gap toward curbing resistance expansion.

Overcoming Multidrug Resistance of Antibiotics via Nanodelivery Systems.

Antibiotic resistance has become a threat to microbial therapies nowadays. The conventional approaches possess several limitations to combat microbial infections. Therefore, to overcome such complications, novel drug delivery systems have gained pharmaceutical scientists’ interest. Significant findings have validated the effectiveness of novel drug delivery systems such as polymeric nanoparticles, liposomes, metallic nanoparticles, dendrimers, and lipid-based nanoparticles against severe microbial infections and combating antimicrobial resistance. This review article comprises the specific mechanism of antibiotic resistance development in bacteria. In addition, the manuscript incorporated the advanced nanotechnological approaches with their mechanisms, including interaction with the bacterial cell wall, inhibition of biofilm formations, activation of innate and adaptive host immune response, generation of reactive oxygen species, and induction of intracellular effect to fight against antibiotic resistance. A section of this article demonstrated the findings related to the development of delivery systems. Lastly, the role of microfluidics in fighting antimicrobial resistance has been discussed. Overall, this review article is an amalgamation of various strategies to study the role of novel approaches and their mechanism to fight against the resistance developed to the antimicrobial therapies.

NMR Hydrophilic Metabolomic Analysis of Bacterial Resistance Pathways Using Multivalent Antimicrobials with Challenged and Unchallenged Wild Type and Mutated Gram-Positive Bacteria.

Multivalent membrane disruptors are a relatively new antimicrobial scaffold that are difficult for bacteria to develop resistance to and can act on both Gram-positive and Gram-negative bacteria. Proton Nuclear Magnetic Resonance (1H NMR) metabolomics is an important method for studying resistance development in bacteria, since this is both a quantitative and qualitative method to study and identify phenotypes by changes in metabolic pathways. In this project, the metabolic differences between wild type Bacillus cereus (B. cereus) samples and B. cereus that was mutated through 33 growth cycles in a nonlethal dose of a multivalent antimicrobial agent were identified. For additional comparison, samples for analysis of the wild type and mutated strains of B. cereus were prepared in both challenged and unchallenged conditions. A C16-DABCO (1,4-diazabicyclo-2,2,2-octane) and mannose functionalized poly(amidoamine) dendrimer (DABCOMD) were used as the multivalent quaternary ammonium antimicrobial for this hydrophilic metabolic analysis. Overall, the study reported here indicates that B. cereus likely change their peptidoglycan layer to protect themselves from the highly positively charged DABCOMD. This membrane fortification most likely leads to the slow growth curve of the mutated, and especially the challenged mutant samples. The association of these sample types with metabolites associated with energy expenditure is attributed to the increased energy required for the membrane fortifications to occur as well as to the decreased diffusion of nutrients across the mutated membrane.

Diptool-A Novel Numerical Tool for Membrane Interactions Analysis, Applying to Antimicrobial Detergents and Drug Delivery Aids.

The widespread problem of resistance development in bacteria has become a critical issue for modern medicine. To limit that phenomenon, many compounds have been extensively studied. Among them were derivatives of available drugs, but also alternative novel detergents such as Gemini surfactants. Over the last decade, they have been massively synthesized and studied to obtain the most effective antimicrobial agents, as well as the most selective aids for nanoparticles drug delivery. Various protocols and distinct bacterial strains used in Minimal Inhibitory Concentration experimental studies prevented performance benchmarking of different surfactant classes over these last years. Motivated by this limitation, we designed a theoretical methodology implemented in custom fast screening software to assess the surfactant activity on model lipid membranes. Experimentally based QSAR (quantitative structure-activity relationship) prediction delivered a set of parameters underlying the Diptool software engine for high-throughput agent-membrane interactions analysis. We validated our software by comparing score energy profiles with Gibbs free energy from the Adaptive Biasing Force approach on octenidine and chlorhexidine, popular antimicrobials. Results from Diptool can reflect the molecule behavior in the lipid membrane and correctly predict free energy of translocation much faster than classic molecular dynamics. This opens a new venue for searching novel classes of detergents with sharp biologic activity.

The role of currently used medicinal plants in aquaculture and their action mechanisms: A review

AbstractGlobal aquaculture development increased rapidly in recent years, and the sector has become one of the fastest‐growing industries in the animal‐derived food production system. However, disease outbreak remains a major challenge that hinders sustainable production through an advanced level of intensification. Recently, antibiotics applied have been restricted globally against aquatic disease outbreaks due to their apparent accumulation in the tissues, which imposes on the development of resistant bacteria. Naturally available medicinal plants were tested to combat some pathogens affecting humans and animals, as they contain a wide range of active substances that can induce biological functions. Currently, medicinal plants are being tested in aquaculture as a safe and eco‐friendly substance to modulate immune status, enhance growth performance and prevent fish disease. Moreover, different parts (e.g. leaf, flower and rhizome) and forms (e.g. crude, extract and active ingredient) of plants are used to modulate specific biological functions (e.g. growth promoter, anti‐stress, immunostimulants, appetite stimulation, antibacteria, anti‐parasite and anti‐virus). Medicinal plants are also used to defend the aquaculture animal from external stressors, such as poor water quality, high environmental temperature and overcrowding. This paper aims to provide information on the role of currently used medicinal plants on aquaculture animals and their action mechanisms. In conclusion, the current review suggested that the utilisation of medicinal plants remained untapped in uncovering the biological activities of active substances against a variety of diseases across diverse species of aquaculture animals.

Extrapulmonary Tuberculosis: An Otorhinolaryngologist's Perspective.

The study aimed to determine the clinical manifestations and epidemiology of extrapulmonary tuberculosis (EPTB) of the head and neck in the otorhinolaryngeal regions. There is an increase in the incidence of EPTB in recent years because of increase in immunocompromised states and development of resistant bacteria. The clinical symptoms and signs of EPTB of the otorhinolaryngeal regions overlap with that of malignancies and other diseases in otorhinolaryngology thereby requiring correct early diagnosis so as to avoid unnecessary surgeries and procedures with initiation of appropriate anti tuberculous treatment under RNTCP. Our prospective study was done on 45 patients who attended the ENT OPD at a tertiary care centre in Southern India over a period of 18months with diagnosed EPTB of the otorhinolaryngeal regions. The study included 29 (64.4%) patients who presented with cervical lymphadenopathy, 11 (24.4%) patients with tuberculous laryngitis, 3 (6.6%) patients with tuberculous otitis media and 1 each with nasal and oral cavity tuberculosis. In our study 6 (13.3%) patients had co-existing pulmonary tuberculosis, 8 (18%) had diabetes, 5 (11%) had past history of tuberculosis and 7 (16%) had contact with patient with tuberculosis. A high index of suspicion of EPTB must be kept among patients where (i) the clinical symptoms are out of proportion to the signs, (ii) common treatment fails or (iii) there is persistence or recurrence of symptoms despite therapy. The challenge is in confirming diagnosis which requires histopathological examination (HPE) of the tissue specimen. The timely diagnosis and initiation of anti tuberculous treatment (ATT) as per RNTCP helps in complete recovery thereby reducing morbidity.

Elimination from wastewater of antibiotics reserved for hospital settings, with a Fenton process based on zero-valent iron

The Fenton process activated by Zero Valent Iron (ZVI-Fenton) is shown here to effectively remove antibiotics reserved for hospital settings (specifically used to treat antibiotic-resistant infections) from wastewater, thereby helping in the fight against bacterial resistance. Effective degradation of cefazolin, imipenem and vancomycin in real urban wastewater was achieved at pH 5, which is quite near neutrality when compared with classic Fenton that works effectively at pH 3–4. The possibility to operate successfully at pH 5 has several advantages compared to operation at lower pH values: (i) lower reagent costs for pH adjustment; (ii) insignificant impact on wastewater conductivity, because lesser acid is required to acidify and lesser or no base for neutralization; (iii) undetectable release of dissolved Fe, which could otherwise be an issue for wastewater quality. The cost of reagents for the treatment ranges between 0.04 and 0.07 $ m−3, which looks very suitable for practical applications. The structures of the degradation intermediates of the studied antibiotics and their likely abundance suggest that, once the primary compound is eliminated, most of the potential to trigger antibiotic action has been removed. Application of the ZVI-Fenton technique to wastewater treatment could considerably lower the possibility for antibiotics to trigger the development of resistance in bacteria.

Exploring Nature’s Treasure to Inhibit β-Barrel Assembly Machinery of Antibiotic Resistant Bacteria: An In silico Approach

Background: The development of antibiotic resistance in bacteria is a matter of global concern due to the exceptionally high morbidity and mortality rates. The outer membrane of most gram-negative bacteria acts as a highly efficient barrier and blocks the entry of the majority of antibiotics, making them ineffective. The Bam complex, β-barrel assembly machinery complex, contains five subunits (BamA, B, C, D, E), which plays a vital role in folding and inserting essential outer membrane proteins into the membrane, thus maintaining outer membrane integrity. BamA and BamD are essential subunits to fulfill this purpose. Therefore, targeting this complex to treat antibiotic resistance can be an incredibly effective approach. Natural bacterial pigments like violacein, phytochemicals like withanone, semasin, and several polyphenols have often been reported for their effective antibiotic, antioxidant, anti-inflammatory, antiviral, and anti-carcinogenic properties. Objective: Structural inhibition of the Bam complex by natural compounds can provide safe and effective treatment for antibiotic resistance by targeting outer membrane integrity. Methods: In-silico ADMET and molecular docking analysis was performed with ten natural compounds, namely violacein, withanone, sesamin, resveratrol, naringenin, quercetin, epicatechin, gallic acid, ellagic acid, and galangin, to analyse their inhibitory potential against the Bam complex. Results: Docking complexes of violacein gave high binding energies of -10.385 and -9.46 Kcal/mol at C and D subunits interface and at A subunits of the Bam complex, respectively. Conclusion: Henceforth, violacein can be an effective antibiotic against to date reported resistant gram-negative bacteria by inhibiting the Bam complex of their outer membrane. Therefore the urgent need for exhaustive research in this concern is highly demanded.

Role and place of levofloxacin in the treatment of community-acquired pneumonia

Lower respiratory tract infections are the third mortality cause in the world and the first mortality cause in low-income countries. Community-acquired pneumonia (CAP) is a dangerous infectious pathology, especially in children younger than 5 years, elderly people and patients with compromised immunity. Antibiotic therapy is a standard treatment method for CAP. But an increase in antibiotics use caused a development of resistance in bacteria and onset of adverse events in humans. A new class of fluorchinolones is widely used nowadays in clinical practice. They have good activity against Gram-negative bacteria, as early chinolones, as well as against Gram-positive bacteria, such as pneumococci and atypical bacteria. An increasing amount of penicillin-resistant streptococcal pneumonia leads to more intensive studies of the use of new chinolones. In this review the data of 750 mg levofloxacin is presented. It is used in short courses for the treatment of severe and moderate CAP. Taking into account the broad spectrum of activity of levofloxacin ad bactericidal activity of this antibiotic, it can be a potential alternative therapy for the treatment of children and adults with CAP, especially with a tendency of an increase in antibiotic resistance of pneumococcus.

Determination of antibiotics and other veterinary drugs in the solid phase of pig manure

The presence of residues of veterinary pharmaceuticals in farm wastewaters such as pig slurry represents a problem that needs to be tackled to avoid further contamination of environmental waters and the development of resistant bacteria. For their monitoring and control, it is necessary the existence of reliable analytical tools. The present paper describes for the first time the development and optimization by statistical experimental design of a specifically designed analytical method for the analysis of 21 veterinary drugs, including 18 antibiotics of several families (β-lactams, tetracyclines, fluoroquinolones, sulfonamides, macrolides, among others), 1 antiparasitic, 1 analgesic and 1 hormone, in a complex environmental matrix such as the fresh solid phase of pig slurry. The resulting method, consisted of an ultrasound assisted extraction (UAE) combined with in-situ dispersive solid phase extraction (d-SPE) from a 0.3 g of freeze-dried sample aliquot followed by a preconcentration step by compact solid phase extraction (c-SPE) and subsequent instrumental analysis by ultra-high-performance-liquid-chromatography (UHPLC) coupled to mass spectrometry in tandem (MS/MS) by a triple quadrupole, was successfully validated as a very sensitive (method limit of quantification in the low ng g−1) and reliable method (relative recoveries around 100% and method repeatability featured by a general relative standard deviation below 20%). Provided raw data was intended to be processed by matrix-matched quantification approach. The resulting methodology was applied to the characterization of several pig manures from different Spanish farms sampled across breeding season between 2018 and 2019. Sample precedence showed to have a high impact in the positives, its frequency and concentration.