Frequent Use Of Antibiotics Research Articles

Impact of Early Empiric Antibiotic Regimens on the Gut Microbiota in Very Low Birth Weight Preterm Infants: An Observational Study.

Frequent use of antibiotics in preterm infants disturbs their gut microbial balance. In this preliminary observational study, we investigated the effect of different antibiotic regimens, administered during the first week of life, on microbial composition and diversity in very low birth weight (VLBW) preterm infants. We performed fecal sampling of breastfed VLBW infants on days 7, 14, and 30. After excluding stool samples from infants who received probiotics or who were administered antibiotics beyond the age of 7 days, we compared gut microbiota profiles between infants receiving a combination of ampicillin and gentamicin for 3 days (AG group, n = 10) and those receiving a combination of ampicillin and cefotaxime for 7 days (AC group, n = 14) using 16S ribosomal DNA community profiling. We also assessed the changes over time in each group. Compared to the AG group, Enterococcus species were significantly more abundant in the AC group (P = 0.002), especially in 7-day samples (12.3 vs. 0.6%, respectively, P = 0.032). No difference was observed at phylum and genus level over time within each group. Species richness in the AC group decreased significantly in the 14-day (P = 0.038) and 30-day (P = 0.03) samples compared to that in the 7-day sample. The same was observed for microbial evenness; in contrast, no significant difference in Shannon index and beta-diversity was detected between the two groups. Controlling for relevant confounding variables did not change the results. In conclusion, different antibiotic regimens affect the early development of gut microbiota in VLBW preterm infants. Prolonged use of ampicillin and cefotaxime might result in overabundance of Enterococcus. However, given that no significant differences were observed in 1-month samples, bacterial genera appear to continue colonizing the gastrointestinal tract despite previous exposure to antibiotics. The clinical relevance of these findings should be elucidated by further studies.

Alta sensibilidad a la mupirocina en aislados de Staphylococcs aureus que colonizan pacientes en hemodiálisis en una unidad renal de Medellín, Colombia

Objetivo: describir el porcentaje de resistencia a la mupirocina y a otros antibióticos en aislados de Staphylococcus aureus que colonizan pacientes en hemodiálisis.
 Métodos: estudio descriptivo en el que se incluyeron pacientes en hemodiálisis en una unidad renal de Medellín. La colonización por S. aureus fue evaluada en las fosas nasales y en la piel. La identificación bacteriana se realizó por PCR y la sensibilidad antibiótica se determinó por el sistema automatizado VITEK-2 y por el método E-test. Las características clínicas de los pacientes fueron evaluadas con la historia clínica.
 Resultados: se incluyeron 210 pacientes, de estos el 50,5 % (n = 106) fueron mujeres, con una mediana para la edad de 62 años (RIC 51,87-71,13). De las características clínicas se destacó el uso frecuente de antibióticos: 59 % (n = 124) y la historia de hospitalización: 69 % (n = 145). El porcentaje de colonización por S. aureus fue de 33,8 % (n = 71) y el sitio más frecuente de colonización fue las fosas nasales (19 %; n = 40). Todos los aislados fueron sensibles a la mupirocina por el método de VITEK-2. Sin embargo, un aislado presentó resistencia de bajo nivel a la mupirocina por E-test. La colonización por aislados resistentes a meticilina (SARM) fue de 4,8 % (n = 10) y estos presentaron, principalmente, resistencia solamente a la oxacilina (58,3 %; n = 7).
 Conclusión: la alta sensibilidad a la mupirocina en aislados de S. aureus colonizantes sugiere su uso como terapia profiláctica en pacientes en hemodiálisis con alto riesgo de infección. Es importante fortalecer los programas de uso racional de antibióticos para evitar la diseminación de mecanismos de resistencia a estos y a otros en las unidades renales.

Occurrence of Cryptosporidium and other enteropathogens and their association with diarrhea in dairy calves of Buenos Aires province, Argentina

Cryptosporidiosis of neonatal dairy calves causes diarrhea, resulting in important economic losses. In Argentina, prevalence values of Cryptosporidium spp. and other enteropathogens such as group A rotavirus (RVA), bovine coronavirus (BCoV) and enterotoxigenic Escherichia coli (ETEC, endotoxin STa+), have been independently studied in different regions. However, an integrative epidemiological investigation on large-scale farms has not been carried out. In this study, fecal samples (n=908) were randomly collected from diarrheic and healthy calves from 42 dairy farms, and analyzed for the presence of Cryptosporidium spp., RVA, BCoV, ETEC (STa+) and Salmonella spp. In all sampled dairy farms, dams had been vaccinated against rotavirus and gram-negative bacteria to protect calves against neonatal diarrhea. The proportion of calves shedding Cryptosporidium spp., RVA, and BCoV in animals younger than 20days of age were 29.8%, 12.4% and 6.4%, and in calves aged between 21 and 90days, 5.6%, 3.9%, and 1.8%, respectively. ETEC was absent in the younger, and occurred only sporadically in the older group (0.9%), whereas Salmonella spp. was absent in both. The observed sporadic finding or even absence of bacterial pathogens might be explained by the frequent use of parenteral antibiotics in 25.3% and 6.5% of the younger and the older group of calves, respectively, within 2days prior to sampling and/or vaccination of dams against gram-negative bacteria. Diarrhea was observed in 28.8% (95% CI, 24.7-32.8%) of the younger calves and 11.7% (95% CI, 9.1-15.5%) of the older calves. Importantly, Cryptosporidium spp. (odds ratio (OR)=5.7; 95% CI, 3.3-9.9; p<0.0001) and RVA (OR=2.5; 95% CI, 1.2-5.1; p<0.05) were both found to be risk factors for diarrhea in calves younger than 20days old. Based on its high prevalence and OR, our results strongly suggest that Cryptosporidium spp. is the principal causative factor for diarrhea in the group of neonatal calves, whereas RVA seems to play a secondary role in the etiology of diarrhea in the studied farms, with about three-times lower prevalence and a half as high OR. Furthermore, a coinfection rate of Cryptosporidium spp. and RVA of 3.7% was observed in the group of younger calves, which strengthens the assumption that these events are independent. In contrast, due to a low infection rate of enteropathogens in older calves, mixed infection (<< 1%) was virtually absent in this group.

Survey on the use of antibiotics in exotic pets among Swiss veterinarians

Monitoring programs and guidelines on the use of antibiotics and antibiotic resistance in human and veterinary medicine have been developed worldwide to promote the prudent use of antibiotics in recent years. However, such information on the use of antibiotics in exotic pets is absent. This fact must be taken into account, since the number of exotic pet patients is constantly increasing and the administration of antibiotics is particular challenging due to the diversity of species and the differences in physiology. The present study reports the results of a survey of frequently used antibiotics and the criteria of antibiotic usage in exotic pets (rabbits, rodents, birds and reptiles) among Swiss veterinarians. These data should form the basis for the development of antibiotic usage guidelines in exotic pets. A total of 61 veterinarians returned the questionnaire. The most important decision-making criteria for antibiotic treatment and antibiotic selection were clinical symptoms (55/59, 93% for antibiotic treatment and 40/59, 68% for antibiotic selection), experience (41/59, 69% and 36/59, 61%, respectively) and textbooks (39/59, 66% and 40/59, 68%). The most important decision-making criteria for dosage and duration of therapy were textbooks (59/59, 100%) and experience (31/59, 53%). The use of a microbial culture was used as a decision criterion for both antibiotic treatment and antibiotic selection by 39% of the participants, sensitivity testing was chosen as a decision criterion by 37% for antibiotic treatment and by 46% for antibiotic selection. Fluoroquinolones were used most frequently, 46/56 (82% of the participants) for rabbits, 49/57 (86%) for rodents, 36/37 (97%) for reptiles and 38/46 (83%) for birds. The vast majority of veterinarians (57/58, 98%) would consult a guide for the use of antibiotics. The frequent use of critical antibiotics in exotic pets underscores the need for a guide to the prudent use of antibiotics. The positive influence of such guidelines has already been proven in dogs and cats.

Febrile reaction after hematopoietic stem cell infusion is more frequent if no steroid premedicaton is given which results in more frequent use of antibiotics in early post-transplant phase

Background: There is no consensus as to the need for steroid premedication before fresh product hematopoietic stem cell (HSC) infusion. In case of febrile reaction post-HSC infusion, on-call staff frequently prescribe antibiotics empirically. Considering the recent data on the value of microbiota and its influence on GVHD incidence, we analysed the frequency of febrile reactions and the use of antibiotic after HSC infusion in 149 consecutive patients. Methods: In the time period between 1/2018 and 10/2019, 149 patients were subject to transplantation in our institution. Per institutional standard operating procedure (SOP), all the patients received premedication before hematopoietic stem cell infusion consisting of 20 mg chloropyramine-chlorid iv, and in case of ABO incompatible graft 1 mg/kg methylprednisolone iv. Retrospective data was collected by using patient charts. Survival probability was calculated by applying Kaplan-Meier method. Results: Fifty-two patients received steroids, 12 patients (23%) developing fever after graft infusion, 46 patients received no steroids, 26 of them (57%) developed fever (p&amp;lt;0.001). There was no difference in the number of patients having positive blood cultures. Nine (17%) and 16 (35%) patients received IV antibiotics in the “steroid” and no-steroid” group, respectively (p&amp;lt;0.05). There was no difference in survival between “steroid” and “no-steroid” group. Conclusions: Even with no difference in the frequency of febrile episodes caused by systemic infection, a significantly more patients not receiving steroid premedication develop fever and are treated with IV antibiotics, which could potentially have further implications on transplantation outcomes due to its influence on microbiota early post-transplant.

Antibiotic Therapy Associated Cardiotoxicity

The improper and frequent use of antibiotics has been on a rise. Empirical use for unapproved indications leads to development of resistant pathogens. Many other adverse drug reactions are associated with the use of antibiotics. These may be due to the direct effect of these drugs or due to their interactions with other therapeutic agents. Cardiac toxicities like QT prolongation, aortic aneurysms and dissections are of high concern and may result in long-term health risks. To prevent these adverse reactions, antibiotics should be used as per the manufacturer’s and physician’s instructions. The use of interacting drugs should be avoided wherever possible. Polypharmacy practice should be done after considering all the patient’s health aspects. This review summarizes the cardiac toxicities of commonly prescribed antibiotics and their interactions with other drugs.

Safety and efficacy of fecal microbiota transplantation to treat and prevent recurrent Clostridioides difficile in cancer patients.

Background: Cancer patients are at increased risk of recurrent Clostridioides difficile infection (rCDI) due to malignancy itself, cancer therapy, and frequent antibiotic use and have a lower response rate to standard oral antibiotics. There are limited data on the safety and efficacy of fecal microbiota transplantation (FMT) for treating rCDI in cancer patients. We aim to describe our experience of using FMT to treat rCDI at a tertiary cancer center.Methods: We conducted a retrospective study of cancer patients who underwent FMT for rCDI at The University of Texas MD Anderson Cancer Center from June 2017 through January 2020. Baseline clinical data and risk factors related to rCDI and FMT were evaluated and compared between cancer types and between cases with remission and recurrence.Results: A total of 19 patients were studied: 12 with solid malignancies and 7 with hematologic malignancies. Most patients had stage IV cancer, and 21% of patients were in cancer remission. On average, patients had 2 episodes of CDI and received 3 courses of antibiotics within 1 year before FMT. 84% of patients with rCDI responded to FMT. Compared with patients who had CDI remission following FMT, non-remission cases were more likely to have received antibiotics following FMT. There were no serious adverse events or mortality within 30 days associated with FMT.Conclusions: FMT is safe, well-tolerated, and efficacious in treating rCDI in selected cancer patients. However, additional antibiotic use for complications from chemotherapy or immunosuppression negatively affected the efficacy of FMT in this population with advanced cancer.

Nosiheptide analogues as potential antibacterial agents via dehydroalanine region modifications: Semi-synthesis, antimicrobial activity and molecular docking study

The frequent and inappropriate use of antibiotics aggravate the variation and evolution of multidrug-resistant bacteria, posing a serious threat to public health. Nosiheptide (NOS) has excellent lethality against a variety of Gram-positive bacteria, however the physical and chemical drawbacks hamper its routine application in clinical practice. In this study, by using NOS as the starting material, a total of 15 NOS analogues (2a-4e) were semi-synthesized via its dehydroalanine residue reacting with monosubstituted anilines. In vitro antimicrobial susceptibilities of NOS and its analogues against two methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE) clinical isolates were determined by broth microdilution assay to determine the minimum inhibitory concentration (MIC). Antimicrobial susceptibility testing data shown that most of the NOS analogues had a better antibacterial effect than the parent compound, with compound 3c exhibiting the highest antibacterial activity against VRE (MIC = 0.0078 mg/L) and MRSA (MIC < 0.0039 mg/L). Molecular docking of synthetic compounds was also performed to verify the binding interactions of NOS analogues with the target. Our data indicated that compound 3c possesses stronger and more complex intermolecular force than other analogues, which is consistent with the results of the biological activity evaluation. Overall, this study identified a number of potential antibacterial NOS analogues that could act as potent therapeutic agents for multidrug-resistant bacterial infections.

Low temperature preservation: Influence of putative bioactive microalgae and hop extracts on sperm quality and bacterial load in porcine semen

The frequent use of antibiotics in artificial insemination promotes the development of antibiotic resistance. Therefore, alternatives must be considered. In this study, putative bioactive microalgae and hop extracts were examined to estimate their effect on quality and bacterial load of preserved porcine semen when used a low-temperature storage at 5 °C in Androstar® Premium (ASP) extender (Minitüb). Firstly, five algae extracts (Neochloris oleoabundans (NEO), Pseudococcomyxa simplex (PSEY), Phormidium ambiquum (PHA), Schizochlamydella minutissima (SCH), Cyanidioschyzon merolae (CYA)) and one hop extract (Humulus lupulus (HOP)) in four concentrations (0.2, 2, 20 and 200 μg/mL) were tested on their sperm-compatibility at 17 °C. All extracts in the concentrations 0.2 and 2 μg/mL appeared to be sperm compatible. After 72 h of storage at 5 °C, variants showed an increase of total bacterial subcultures from 103 (ASP w/o supplements) to 113/136/135/136/126/118 (ASP w/NEO/PSEY/PHA/HOP/SCH/CYA). Even though bacterial growth was not inhibited in general, all extracts showed an antimicrobial effect on specific bacteria, including Gram-positive (Trueperella pyogenes, Streptococcus porcinus) and Gram-negative bacterial species (Alcaligenes faecalis, Pseudomonas aeruginosa, Ralstonia sp., Pasteurella sp., Proteus sp., Providencia stuartii, and Escherichia coli). While the proportion of these species was 10% in the control (ASP w/o supplements), their proportion in the supplemented variants ranged from 8% (NEO, HOP) to as low as 3% (PSEY). Although the tested extracts are not suitable to replace conventional antibiotics due to their lack of broad-spectrum antimicrobial activity, they nevertheless present promising opportunities for bacteria-specific, customizable usage in boar semen extenders combined with antibiotics or other antimicrobial agents.

Upper-airway dysbiosis related to frequent sweets consumption increases the risk of asthma in children with chronic rhinosinusitis.

Innate immunity response to local dysbiosis seems to be one of the most important immunologic backgrounds of chronic rhinosinusitis (CRS) and concomitant asthma. We aimed to assess clinical determinants of upper-airway dysbiosis and its effect on nasal inflammatory profile and asthma risk in young children with CRS. We recruited one hundred and thirty-three children, aged 4-8years with doctor-diagnosed CRS with or without asthma. The following procedures were performed in all participants: face-to-face standardized Sinus and Nasal Quality of Life questionnaire, skin prick test, taste perception testing, nasopharynx swab, and sampling of the nasal mucosa. Upper-airway dysbiosis was defined separately by asthma-specific microbiome composition and reduced biodiversity. Multivariate methods were used to define the risk factors for asthma and upper-airway dysbiosis and their specific inflammatory profile of nasal mucosa. The asthma-specific upper-airway microbiome composition reflected by the decreased ratio of Patescibacteria/Actinobacteria independently of atopy increased the risk of asthma (OR:8.32; 95%CI: 2.93-23.6). This asthma-specific microbiome composition was associated with≥7/week sweet consumption (OR:2.64; 95%C:1.11-6.28), reduced biodiversity (OR:3.83; 95%CI:1.65-8.87), the presence of Staphylococcus strains in the nasopharynx (OR:4.25; 95%CI:1.12-16.1), and lower expression of beta-defensin 2, IL-5, and IL-13 in the nasal mucosa. The reduced biodiversity was associated with frequent antibiotic use and with a higher nasal expression of IL-17 and T1R3 (sweet taste receptor). In asthmatic children, reduced sweet taste perception was observed. Specific upper-airway dysbiosis related to frequent sweet consumption, frequent antibiotic courses, and altered nasal immune function increases the risk of asthma in young children with CRS.

Evaluation of the efficacy of Chinese Children's Asthma Action Plan on the long-term management of children with asthma at home

Objective: During the COVID-19 pandemic, the electronic "questionnaire star" was employed to investigate the general situation, medication situation and pandemic impact of children diagnosed with asthma in our hospital and enrolled in the electronic platform of the Chinese Children's Asthma Action Plan (CCAAP). The internet technology and big data were used to grasp the trend and asthma control of children who had been at home for a long time due to the pandemic, so as to facilitate the management. Methods: By random cluster sampling survey method, according to the needs and medication adherence score, the electronic "questionnaire star" was designed to conduct a survey among children (0 to 14 years old) who diagnosed with asthma and joined the CCAAP on the basis of bronchial asthma medication adherence scale. Finally, the results of electronic questionnaire survey were analyzed. Results: A total of 423 questionnaires were sent out, 422 of which were valid, with an effective response rate of 99.7%. The results of questionnaire survey showed that 296 cases were male, accounting for 70.1%, and 126 cases were female, accounting for 29.9%, with an average age of (5.4±2.6) years old. The average age of males and females was (5.3±2.6) and (5.4±2.6) years old, respectively. There were more children aged ≥5 years than children who were younger than 5 years. Additionally, 13.95% of the parents thought that the pandemic had more than moderate impact on children with asthma, and 76.12% of the children were in the green zone and had no asthma attack. The proportion of green zone inhaled drugs (79.8%) was higher than yellow zone and red zone (49.8%). After using the CCAAP platform, the dissatisfaction rate was only 1.42%. Moreover, 71.87% of the children's medical expenses decreased, and the proportion of frequent use and intermittent use of antibiotics reduced, however, the proportion of occasional use and never use of antibiotics increased significantly (all P<0.05). The average score of drug compliance was 4.56, and the more frequently the platform was used, the higher the score of medication compliance was (P<0.05). Conclusions: After using CCAAP management with the aid of internet technology, children with asthma who had been isolated at home for a long time were less affected by COVID-19, with high medication compliance, generally lower medical expenses, significantly reduced use of antibiotics, and high satisfaction. This management mode provides a new idea for internet medicine.

Reduced graphene oxide-chitosan flexible nanocomposites for efficient bacteria capture and photothermal ablation

AbstractOne of the major public health concerns today is bacterial infection-associated diseases. Traditional antibacterial therapies are becoming less efficient because frequent and inadequate use of antibiotics has caused mutations in bacteria that led to many antibiotic-resistant bacterial strains. It is, therefore, crucial to develop novel antibacterial materials and strategies that will successfully combat both gram-positive and gram-negative bacteria. In the present study, we will demonstrate a simple and efficient method for bacteria capture and elimination through photothermal ablation. The developed material consists of a flexible Kapton substrate, coated with reduced graphene oxide-chitosan (rGO-CS) thin films. Reduced graphene oxide has strong absorption in the near-infrared (NIR) region, while chitosan has the ability to bind bacteria through electrostatic interactions. The K/rGO-CS device proved to capture and efficiently eradicate both planktonic Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) bacteria after 10 min of NIR (980 nm) irradiation.

In vitro antibacterial activity of ethanol extract ofArtemisia annuaand its bioactive fractions against fish pathogens

Bacterial pathogens cause significant economic losses in fish farms worldwide. The frequent use of antibiotics is a growing concern due to the adverse effects on human health and the environment. We evaluate the antibacterial activity of the Artemisia annua and its bioactive components against the Aeromonas hydrophila, Streptococcus agalactiae and Flavobacterium columnare, the main bacteria that affect fish culture. Bioactive components of the A. annua were obtained using an alcoholic extraction process, yielding 10.6% of dry material. The alcoholic extract of A. annua (ae-Aa) bioactive compounds was fractionated, obtaining the fractions F1 + 2, F3, F4, F5 and F6. Artemisinin up to 10.0 mg.ml-1 was ineffective in controlling studied bacteria. Microorganisms tested were all sensitive to ae-Aa (MIC and MBC 0.40 to 2.50 mg.ml-1). The ae-Aa components F3, F4, F5 and F6 were also effective (MIC and MBC 0.015 to 2.00 mg.ml-1). F3 showed the most effective antibacterial activity (MIC 0.015 to 0.5 mg.ml-1 and MBC 0.015 to 2.0 mg.ml-1). The ae-Aa and its bioactive components presented efficacy to inhibit growth and eliminate bacterial pathogens and can be an alternative to synthetic antibiotics for farmed fish.

Assessment and treatment of recurrent urinary tract infections in women: development of a questionnaire based on a qualitative study of patient expectations in secondary care

BackgroundTo develop a questionnaire to facilitate the inventorying of women’s expectations for the assessment and treatment of recurrent urinary tract infection (UTI) in secondary care.MethodsSemi-structured interviews were conducted among women with recurrent UTI referred to our urology department. The interviews were conducted by one interviewer, recorded, transcribed verbatim, and analyzed thematically by two researchers. We first developed 35 questions to identify potential themes, and we then tested them among women with and without recurrent UTI. Changes were made according to the feedback received.ResultsSix interviews were conducted before saturation was reached. Thematic analysis identified three themes: patient pathway, personal knowledge, and social implications. All respondents had received multiple antibiotic courses but no prophylactic antibiotic therapy, and although all were aware of some preventive measures, they wanted more information about their disease. However, some women were afraid to access information for fear of what they might learn. Recurrent UTI also significantly affected the daily lives all respondents. Some women expressed fears over frequent antibiotic use, and others felt that there must be something wrong with their body to have so many UTIs. Women expected the urologist to provide an explanation and to start adequate therapy for their recurrent UTI. We created a 32-item questionnaire based on these themesConclusionThis study not only developed a questionnaire for use when assessing patient expectations of recurrent UTI management in secondary care but also provided novel insights into the thoughts, opinions, and expectations of women who are referred.

PROSPECTS OF ANTIQUORUM SUBSTANCES AS AN ALTERNATIVE TO ANTIBIOTIC THERAPY IN ANIMAL HUSBANDRY (review)

Frequent and inappropriate use of antibiotics in animal husbandry threatens to expand the spectrum of antibiotic-resistant bacteria. Quorum sensing (QS) is one of the mechanisms responsible for this process. For its implementation, bacteria use autoinducers, the special signaling molecules for information exchange (A.A. Miller et al., 2011). The studies to give insight of this mechanism have shed light on the existence of substances that act as Quorum sensing inhibitors (quorum suppressors) (B. Remy et al., 2018), which made such studies even more relevant (J. Bzdreng et al., 2017). In our review, we have summarized the latest data on the search and development of the biologically active compounds that can become an alternative to antibiotic drugs used in animal husbandry. These include bacterial enzymes (AGL-lactonases, AGL-acylases, decarboxylases, and deaminases) that can degrade quorum sensing signal autoinducers (V.C. Kalia et al., 2011), as well as α-amylases, β-glucanases, lipases, and proteases involved in the destruction of biofilms (R. Sharma et al., 2001). The antimicrobial properties are also characteristic of animal enzymes acylase I (D. Paul et al., 2010), paraoxonase (J.F. Teiber et al., 2008), and lactonase, plant enzymes laccase (R. Al-Hussaini et al., 2009), alliinase, thiol-dependent enzyme and lactonase derived from garlic and medicinal plants (A. Adonizio et al., 2008), enzymes of marine organisms, particularly bromoperoxidase of the algae Laminaria digitata, alginate lyases from algae, invertebrates, and marine microorganisms, and halogenated furanones of Delisea pulchra (S.A. Borchardt et al., 2001; M. Mane-field et al., 2000). In addition, we can distinguish antimicrobial digestive enzymes used as feed additives, e.g., phytase (O. Adeola et al., 2011), xylanase and lysozyme (G. Cheng et al., 2014). Studies of phytobiotics and essential oils as quorum sensing inhibitors are promising (V.I. Fisinin et al., 2018). Their inhibitory ability is shown due to the similarity of the chemical structures of some plant extracts to the structure of acyl-homoserine-lactone and inactivation of signaling molecules (R. Chevrot et al., 2006; F. Nazzaro et al., 2013). Another prospective alternative is the use of antimicrobial combinatins enabling a synergistic effect due to the variety of mechanisms of overcoming the recurrent bacterial communications and destroying persistent bacterial cells. These polypeptide cocktails may include the combination of antibiotics with natural compounds. The amtimicrobial efficacy has shown for combination of tobramycin and some plant extracts, partilularly cinnamaldehyde and baykalin hydrate against Burkholderia cenocepacia and Pseudomonas aeruginos (G. Brackman et al., 2011), a wide range of antibiotics, e.g., aminoglycosides (T.H. Jakobsen et al., 2012; M. Stenvang et al., 2016), quinolones (Q. Guo et al., 2016), polypeptide antibiotics (A. Furiga et al., 2016; Z.P. Bulman et al., 2017), cephalosporins and glycopeptides (D. Maura et al., 2017), and various quorum sensing inhibitors.

ПЕРСПЕКТИВА ПРИМЕНЕНИЯ ВЕЩЕСТВ АНТИКВОРУМА КАК АЛЬТЕРНАТИВА АНТИБИОТИКОТЕРАПИИ В ЖИВОТНО-ВОДСТВЕ (обзор)

Frequent and inappropriate use of antibiotics in animal husbandry threatens to expand the spectrum of antibiotic-resistant bacteria. Quorum sensing (QS) is one of the mechanisms responsible for this process. For its implementation, bacteria use autoinducers, the special signaling molecules for information exchange (A.A. Miller et al., 2011). The studies to give insight of this mechanism have shed light on the existence of substances that act as Quorum sensing inhibitors (quorum suppressors) (B. Remy et al., 2018), which made such studies even more relevant (J. Bzdreng et al., 2017). In our review, we have summarized the latest data on the search and development of the biologically active compounds that can become an alternative to antibiotic drugs used in animal husbandry. These include bacterial enzymes (AGL-lactonases, AGL-acylases, decarboxylases, and deaminases) that can degrade quorum sensing signal autoinducers (V.C. Kalia et al., 2011), as well as α-amylases, β-glucanases, lipases, and proteases involved in the destruction of biofilms (R. Sharma et al., 2001). The antimicrobial properties are also characteristic of animal enzymes acylase I (D. Paul et al., 2010), paraoxonase (J.F. Teiber et al., 2008), and lactonase, plant enzymes laccase (R. Al-Hussaini et al., 2009), alliinase, thiol-dependent enzyme and lactonase derived from garlic and medicinal plants (A. Adonizio et al., 2008), enzymes of marine organisms, particularly bromoperoxidase of the algae <em>Laminaria digitata</em>, alginate lyases from algae, invertebrates, and marine microorganisms, and halogenated furanones of <em>Delisea pulchra</em> (S.A. Borchardt et al., 2001; M. Mane-field et al., 2000). In addition, we can distinguish antimicrobial digestive enzymes used as feed additives, e.g., phytase (O. Adeola et al., 2011), xylanase and lysozyme (G. Cheng et al., 2014). Studies of phytobiotics and essential oils as quorum sensing inhibitors are promising (V.I. Fisinin et al., 2018). Their inhibitory ability is shown due to the similarity of the chemical structures of some plant extracts to the structure of acyl-homoserine-lactone and inactivation of signaling molecules (R. Chevrot et al., 2006; F. Nazzaro et al., 2013). Another prospective alternative is the use of antimicrobial combinatins enabling a synergistic effect due to the variety of mechanisms of overcoming the recurrent bacterial communications and destroying persistent bacterial cells. These polypeptide cocktails may include the combination of antibiotics with natural compounds. The amtimicrobial efficacy has shown for combination of tobramycin and some plant extracts, partilularly cinnamaldehyde and baykalin hydrate against <em>Burkholderia cenocepacia</em> and <em>Pseudomonas aeruginos</em> (G. Brackman et al., 2011), a wide range of antibiotics, e.g., aminoglycosides (T.H. Jakobsen et al., 2012; M. Stenvang et al., 2016), quinolones (Q. Guo et al., 2016), polypeptide antibiotics (A. Furiga et al., 2016; Z.P. Bulman et al., 2017), cephalosporins and glycopeptides (D. Maura et al., 2017), and various quorum sensing inhibitors.

Identification and antibiotic susceptibility pattern of urinary isolates in out-patients at a tertiary care center in a rural set up

Urinary tract infection (UTI) is most common infections described in out- patients settings. In almost all cases empirical antimicrobial treatment initiates before the laboratory results of urine culture are available, thus antibiotic resistance may increase in uropathogens due to frequent use of antibiotics. To identify and to determine antibiotic susceptibility pattern of bacterial pathogens of urinary tract infection reporting at a tertiary care hospital in OPD only. Cross-sectional. Department of microbiology, NKP salve institute of medical science, Lata Mangeshkar hospital, Nagpur from July to September 2018. A total of 33 culture positive bacterial isolates from 300 urine samples, submitted over a period of 2 months were included in this study. Identification of bacterial isolates was done by standard biochemical profile of the organism. The antibiotic susceptibility of culture positive bacterial isolates was performed by disk diffusion method as recommended by CLSI. Out of 33 culture positive samples the most prevalent bacterial isolate was E. Coli(48%) followed by klebsiella(18%), staphylococcus coagulase negative(12%). The susceptibility pattern of E. Coli showed that 81% of bacterial isolates were sensitive to Nitrofurantoin,75% to CIS and 50% to Gentamicin. Klebsiella was most sensitive to Gentamicin and CIS. Staphylococcus coagulase negative was most sensitive to Cd and Vancomycin. Majority of bacterial isolates were sensitive to nitrofurantoin, CIS, Gentamicin. Among the oral antibiotics, nitrofurantoin showed good susceptibility against Enterobacteriaceae family and gram positive organisms.

Few bacterial co-infections but frequent empiric antibiotic use in the early phase of hospitalized patients with COVID-19: results from a multicentre retrospective cohort study in The Netherlands

Background Knowledge on bacterial co-infections in COVID-19 is crucial to use antibiotics appropriately. Therefore, we aimed to determine the incidence of bacterial co-infections, antibiotic use and application of antimicrobial stewardship principles in hospitalized patients with COVID-19. Methods We performed a retrospective observational study in four hospitals (1 university, 2 non-university teaching, 1 non-teaching hospital) in the Netherlands from March to May 2020 including consecutive patients with PCR-confirmed COVID-19. Data on first microbiological investigations obtained at the discretion of the physician and antibiotic use in the first week of hospital admission were collected. Results Twelve (1.2%) of the 925 patients included had a documented bacterial co-infection (75.0% pneumonia) within the first week. Microbiological testing was performed in 749 (81%) patients: sputum cultures in 105 (11.4%), blood cultures in 711 (76.9%), pneumococcal urinary antigen testing in 202 (21.8%), and Legionella urinary antigen testing in 199 (21.5%) patients, with clear variation between hospitals. On presentation 556 (60.1%; range 33.3–73.4%) patients received antibiotics for a median duration of 2 days (IQR 1–4). Intravenous to oral switch was performed in 41 of 413 (9.9%) patients who received intravenous treatment >48 h. Mean adherence to the local guideline on empiric antibiotic therapy on day 1 was on average 60.3% (range 45.3%–74.7%). Conclusions On presentation to the hospital bacterial co-infections are rare, while empiric antibiotic use is abundant. This implies that in patients with COVID-19 empiric antibiotic should be withheld. This has the potential to dramatically reduce the current overuse of antibiotics in the COVID-19 pandemic.

Identification and characterization of Pseudomonas aeruginosa derived bacteriocin for industrial applications

Drug resistance has become a major threat due to the frequent use of commercial antibiotics and there is an urgent need to combat this problem. Having this in mind, the present research was aimed at developing a novel P. aeruginosa puBac bacteriocin molecule. The bacteriocin was purified by ammonium sulfate precipitation followed by Sepharose FF and Sephadex G15 column purification and the purified bacteriocin has been reported to have the molar mass of 43 kDa. The findings of the optimization showed that 3500 AU/mL of bacteriocin was obtained at 37 °C, 3410 AU/mL of bacteriocin at 6.5 pH and 3780 AU/mL of bacteriocin at 48 h of incubation time. In addition, 3863 AU/mL of bacteriocin activity was obtained with Tween-80 followed by 3789 AU/mL with a concentration of 2% NaCl and 4200 AU/mL for Fe2+. PuBac bacteriocin has been shown to have a significant effect on test pathogens. For example, E. coli was found to have 3.6 μM of MIC, followed by Staphylococcus sp. with 6.15 μM of MIC and Bacillus sp. with a 7.5 μM of MIC. The remarkable properties of bacteriocin suggest that it could be used in various pharmaceutical and food industries.

Antibacterial spectrum of synthetic herbal-based polyphenols against Vibrio parahaemolyticus isolated from diseased Pacific whiteleg shrimp (Penaeus vannamei) in Thailand

Acute hepatopancreatic necrosis disease (AHPND) was first reported as a new shrimp disease in 2009, which caused serious disease in shrimp culture with global economic losses and high rates of mortality. Vibrio parahaemolyticus (VP) was recently identified as the leading causative agent of AHPND that contains Pir toxin bearing plasmid coding toxins (PirA and PirB). Classic antibiotic treatments have been used for the control of infections, however, the frequent use of antibiotics has led to the emergence of antibiotic-resistant bacterial strains of public health concern. The present study aimed to investigate the potential use of synthetic herbal-based polyphenols compounds as natural, eco-friendly antimicrobial agents for disease control. Polyphenols and their active ingredients were investigated against 96 VP isolates retrieved from Pacific whiteleg shrimp (Penaeus vannamei) in Thailand and compared with various commercial antibiotics using a broth microdilution method, time-kill assay, and scanning electron microscope (SEM). All VP isolates were identified using conventional bacteriology and molecular-based tools. Bacteriological examination revealed that all isolates harbored toxR gene with specific amplicons of 368 bp. Only 56 isolates were positive to AP3, a toxin-encoding gene of AHPND-VP with a fragment size of 336 bp. In terms of susceptibility, all isolates were entirely resistant to ampicillin and amoxicillin, whereas they showed different susceptibility patterns to the other tested antibiotics. Among the polyphenols, there was no apparent activity of syringic acid and rutin, while vanillic acid showed higher bactericidal activity against VP isolates at MICs and MBCs of 1024–2048 μg mL−1. Pyrogallol exhibited the strongest antibacterial activity even at very low concentrations with a MIC and MBC of 32–256 μg mL−1, and the majority of cells showed disruption and an indistinguishable cell wall structure by SEM analysis. The present study offers pyrogallol as a potential synthetic herbal-based antimicrobial agent for the adoption of inventory management practices and control of V. parahemolyticus causing AHPND in shrimp producing sectors.