Effect Of Antimicrobial Treatment Research Articles

Change starts at home: summary of the 2023 inaugural Small Animal Antimicrobial Stewardship Workshop for US Veterinary Schools.

Small animal antimicrobial stewardship (AS) is emerging as a priority area in the global battle against antimicrobial resistance. Veterinary practices have limited support for implementation of AS programs, and even within veterinary schools, efforts are largely siloed and often limited in scope. Increased collaboration is needed to support and unify AS and infection prevention and control efforts, and to identify priorities for continued research. To address this, a 2-day in-person small animal AS workshop was held in August 2023. Delegates representing 23 US veterinary schools and 4 corporations/government agencies gathered for a series of lightning talks and focused group discussions in 3 domains: implementation of clinical AS programs, research opportunities and needs, and education. The workshop's goal was to identify and propose solutions for AS challenges. Meeting discussion identified a lack of resources and training as the greatest barriers to hospital AS program advancement and suggested creating standards for AS programs and a road map to support program development. Assessing antimicrobial treatment effects and performing studies to establish necessary treatment durations were considered the highest research priorities. Integrated educational practices were recommended to support unified messaging of AS concepts between preclinical and clinical training. The development of strategies to implement these suggestions was delegated to working groups with a goal to continue meeting biennially as a large group. Sharing news of these efforts is considered integral to heightening awareness and promoting implementation of AS practices moving forward in academic, specialty, and primary care settings.

An in vitro evaluation of the effect of antimicrobial treatment on bovine mammary microbiota

Antimicrobial-resistant bacteria have been an increasing problem in human medicine and animal husbandry since the introduction of antimicrobials on the market in the 1940s. Over the last decades, efforts to reduce antimicrobial usage in animal husbandry have been shown to limit the development of resistant bacteria. Despite this, antimicrobial-resistant bacteria are still commonly detected and isolated worldwide. In this study, we investigated the presence of antimicrobial-resistant bacteria in bovine milk samples using a multiple approach based on culturing and amplicon sequencing. We first enriched milk samples obtained aseptically from bovine udders in the presence of two antimicrobials commonly used to treat mastitis and then described the resistant microbiota by amplicon sequencing and isolate characterization. Our results show that several commensal species and mastitis pathogens harbor antimicrobial resistance and dominate the enriched microbiota in milk in presence of antimicrobial agents. The use of the two different antimicrobials selected for different bacterial taxa and affected the overall microbial composition. These results provide new information on how different antimicrobials can shape the microbiota which is able to survive and reestablish in the udder and point to the fact that antimicrobial resistance is widely spread also in commensal species.

Antimicrobial, phytochemical, and antioxidant characterization of the leaf extracts of Clematis montana and Clematis grata

The worldwide emergence of multidrug-resistant bacterial infections among the population has impaired the existing effectiveness of antimicrobial treatments, necessitating the hunt for other alternatives. We aimed to find the antibacterial and antioxidant activities of Clematis montana and C. grata leaf extracts (both species have medicinal use among the local population). Extracts were assessed against four pathogenic bacterial strains (Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa, and Staphylococcus aureus), through the agar well diffusion method. Total flavonoid content (TFC), total phenolic content (TPC), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity were quantified. Results suggested that all plant extracts, particularly those extracted with methanol, were potentially active in suppressing pathogenic bacterial growth (particularly against P. aeruginosa and E. coli) although their efficiency varied when compared to vancomycin. However, the antibacterial activity of methanolic extracts from both species was not greatly influenced by the method of extraction (maceration/soxhlet apparatus). TFC was significantly higher in the methanolic extracts of both species in comparison to the n-hexane extracts, whereas TPC and DPPH scavenging activity were detected to be highest in the methanolic extract from the leaves of C. grata. Our results suggested that the leaf extracts from both Clematis species, particularly the methanolic-based extract of C. montana, might serve as a promising source of an effective antibacterial agent.

Comparison of the effects of cefmetazole and meropenem on microbiome: A pilot study

BackgroundCefmetazole (CMZ) is a carbapenem-sparing option in the treatment of extended-spectrum beta-lactamase (ESBL)-producing bacterial infection. In this pilot study, we aimed to compare the effects of antimicrobial treatment (meropenem [MP] and CMZ) with those of no antimicrobial treatment (control group) on the microbiome. MethodsThe study was a multicenter, prospective, observational pilot study conducted from October 2020 to October 2022. Feces and saliva samples were collected for microbiome analyses at two time points (early-period: days 1–3; and late-period: days 4–30) for the antimicrobial treatment group, and at one time point for the control group. ResultsFive feces (MP-F and CMZ-F) and five saliva (MP-S and CMZ-S) samples were included in the MP and the CMZ groups. Ten feces (C–F) and saliva (C–S) samples were included in the control group. Group α diversity was notably lower in the late-period MP-F group than the control group as determined with the Shannon richness index. β diversity analysis of the feces samples based on weighted and unweighted UniFrac distances revealed distinctions in both the late-period CMZ-F and MP-F groups compared with the control group. Weighted UniFrac analysis showed that only the early-period MP-F group differed from the control group. In the saliva samples, weighted and unweighted UniFrac analyses showed significant differences between the control group and the early CMZ, late CMZ, and late MP groups. ConclusionsMP treatment may cause larger impact on the feces microbiome than CMZ in Japanese patients.

Influence and metabolomic basis of an indigenous yeast CECA, from Ningxia wine region of China, on the aroma and flavor of Cabernet Sauvignon wines

In this study, three fermentation treatments of spontaneous fermentation (SF), direct inoculation of CECA (YF), and inoculation with CECA after addition of dimethyl dicarbonate (YDF) were carried out. Multivariate statistical analysis approved that CECA inoculation significantly influenced the composition of 141 metabolites (15 volatile organic compounds (VOCs) and 126 non-VOCs), mainly consisting of 36 acids and derivatives and 25 lipids and lipid-like molecules. YF and YDF wines exhibited similar correlations with aroma types, while there were differences in the kinds and number of VOCs. Moreover, CECA-inoculated fermentation was more favorable to the formation of aftertaste-A, umami, sourness, and richness. The KEGG metabolic pathway analysis indicated that the inoculation strategy significantly affected the amino acid metabolism. The antimicrobial treatment effectively enhanced bitterness, astringency, umami and saltiness while reducing acidity. Further studies are needed to assess the effects of antimicrobial treatment on lipid metabolism.

An Integrated Analysis of Abattoir Lung Lesion Scores and Antimicrobial Use in Italian Heavy Pig Finishing Farms.

Respiratory diseases significantly affect intensive pig finishing farms, causing production losses and increased antimicrobial use (AMU). Lesion scoring at slaughter has been recognized as a beneficial practice to evaluate herd management. The integrated analysis of abattoir lesion scores and AMU data could improve decision-making by providing feedback to veterinarians and farmers on the effectiveness of antimicrobial treatments, thus rationalizing their use. This study compared lung and pleural lesion scores collected at Italian pig slaughterhouses with on-farm AMU, estimated through a treatment index per 100 days (TI100). Overall, 24,752 pig carcasses, belonging to 236 batches from 113 finishing farms, were inspected. Bronchopneumonia and chronic pleuritis were detected in 55% and 48% of the examined pigs, respectively. Antimicrobials were administered in 97% of the farms during the six months prior to slaughter (median TI100 = 5.2), notwithstanding compliance with the mandatory withdrawal period. EMA category B (critical) antimicrobials were administered in 15.2% of cases (median TI100 = 0.06). The lung score was not associated with the total AMU, but significant, positive associations were found with the past use of critical antimicrobials (p = 0.041) and macrolides (p = 0.044). This result highlights the potential of abattoir lung lesion monitoring to rationalize antimicrobial stewardship efforts, contributing to AMU reduction.

Confirmed bacteriological diagnosis and cure of nonsevere gram-positive clinical mastitis cases enrolled in a randomized clinical trial based on results of on-farm culture

Our objectives were to describe the confirmed bacteriological diagnosis of mastitis pathogens cultured from cases of nonsevere clinical mastitis (CM) identified as gram-positive (GP) using on-farm culture and to compare differences in bacteriological cure (BC) based on antimicrobial (AM) therapy. Cows that developed nonsevere CM in a single quarter were enrolled in a randomized clinical trial based on microbial growth on GP selective agars. Cows were randomly assigned to receive a once-daily intramammary treatment: 3 d hetacillin (n = 69), 3 d ceftiofur (n = 69), 8 d ceftiofur (n = 70), or to a nontreated group (n = 32). Etiologies were confirmed with MALDI-TOF using frozen duplicate milk samples. The crude proportion of BC was determined using milk samples collected at 14, 21, and 28 d after enrollment for cases caused by streptococci, NAS, Streptococcus-like organisms (consisting of Enterococcus and Lactococcus; SLO), and Staphylococcus aureus. Multivariable models were used to determine the effect of AM treatment on BC cure at d 21 for a subset of cases that had complete data for all covariates (n = 88). Growth on GP agar resulted in enrollment of 240 cases with confirmed etiologies distributed as Streptococcus spp. (21.7%; n = 52), Lactococcus spp. (19.2%; n = 46), NAS (16.3%; n = 39), Staph. aureus (6.3%; n = 16), Enterococcus spp. (5.0%; n = 12), and others (10%; n = 24). Thirty-five (14.5%) duplicate milk samples collected from enrolled cows had no significant growth in the laboratory and 16 (6.7%) were contaminated. Among sampling dates, combined crude BC for cases caused by target pathogens ranged from 68% to 71%. Crude BC ranged from 58% to 73% for the small group of nontreated cases (n = 12) and 69% to 71% for the combined group of cases that received intramammary AM (n = 113). Among all groups and all follow-up dates, crude BC was least for cases caused by Staph. aureus (ranging from 33% to 43%), followed by cases caused by SLO (58%–67%), NAS (79%–80%), and Streptococcus spp. (81%–91%). The proportion of BC at 21 d (LSM ± SE) did not vary between all cases that received AM (0.77 ± 0.06) and cases in the nontreated group (0.73 ± 0.16). The odds of BC at 21 d was about 5× greater for cases that occurred in primiparous as compared with multiparous cows and decreased 1.3-fold for each 1 log unit increase in SCC before the case. While this study does not have sufficient power to detect small differences in BC among pathogen groups or treatments, our results demonstrate that CM is caused by a wide diversity of GP bacteria with varying ranges of BC. These results provide justification for inclusion of negative control groups in future studies and confirm that important characteristics such as parity and history of subclinical mastitis influence the probability of BC.

Influence of gamma radiation treatment on microbial contamination, quality indicators and anthocyanin content in dark raisins

One of the most promising and gentle methods for reducing the number of microorganisms in food and agricultural raw materials is treatment with ionizing radiation. The work aimed to evaluate the effect of antimicrobial treatment with gamma radiation on quality indicators and anthocyanin content in dark raisins. The object of the study was dark raisins produced in Uzbekistan. The studied samples were analyzed according to quality indicators (organoleptic, moisture, color) and microbiological indicators (total microbial contamination, yeast content, mold, and coliform bacteria). The main groups of microorganisms isolated from the surface of raisins were also identified using MALDI-TOF mass spectrometry. The anthocyanin content of the samples was measured by pH differential spectroscopy. Studies have shown that when dark raisins are irradiated in the dose range from 1.5 to 9 kGy, there is a significant decrease in the number of main sanitary-indicative microorganisms. It has been established that the optimal dose for suppressing microflora is 4-6 kGy. Microbial contamination of raisins is mainly caused by molds of the genera Mucor, Rhizopus, and Aspergillus and yeasts of the genera Candida and Phomopsis. As a result of treatment with ionizing radiation, a decrease in the content of anthocyanins by 1.5-2 times was noted. At the same time, no changes in the color, taste, and presentation of raisins were established. Treatment of dark varieties of raisins with gamma radiation can be recommended as an alternative to chemical treatment.

Zophobas morio larvae as a novel model for the study of Acinetobacter virulence and antimicrobial resistance.

The use of mammalian models for in vivo testing of bacterial virulence raises ethical concerns and is expensive and time-consuming. As an alternative, non-mammalian models are sought. Galleria mellonella larvae have been used as a model to study several bacterial pathogens. However, their maintenance is challenging, and commercial supply is low. In this study, we aimed to establish the Zophobas morio larvae as an alternative non-mammalian model for the evaluation of the pathogenicity and antimicrobial susceptibility of Acinetobacter baumannii. We infected Z. morio with Acinetobacter strains and determined the optimal temperature and inoculum. To visualize the bacterial distribution within the larvae, hematoxylin and eosin (H&E) staining was performed. Next, a survival model of infected larvae was established, and virulence was compared between strains. The effect of antimicrobial treatment in relation to antibiotic susceptibility was studied. Our results demonstrate that Z. morio can be used as a model system for in vivo studies of A. baumannii.

Exploring the effects of antimicrobial treatment on the gut and oral microbiomes and resistomes from elderly long-term care facility residents via shotgun DNA sequencing.

Monitoring antibiotic-resistant bacteria (ARB) and understanding the effects of antimicrobial drugs on the human microbiome and resistome are crucial for public health. However, no study has investigated the association between antimicrobial treatment and the microbiome-resistome relationship in long-term care facilities, where residents act as reservoirs of ARB but are not included in the national surveillance for ARB. We conducted shotgun metagenome sequencing of oral and stool samples from long-term care facility residents and explored the effects of antimicrobial treatment on the human microbiome and resistome using two types of comparisons: cross-sectional comparisons based on antimicrobial treatment history in the past 6 months and within-subject comparisons between stool samples before, during and 2-4 weeks after treatment using a single antimicrobial drug. Cross-sectional analysis revealed two characteristics in the group with a history of antimicrobial treatment: the archaeon Methanobrevibacter was the only taxon that significantly increased in abundance, and the total abundance of antimicrobial resistance genes (ARGs) was also significantly higher. Within-subject comparisons showed that taxonomic diversity did not decrease during treatment, suggesting that the effect of the prescription of a single antimicrobial drug in usual clinical treatment on the gut microbiota is likely to be smaller than previously thought, even among very elderly people. Additional analysis of the detection limit of ARGs revealed that they could not be detected when contig coverage was <2.0. This study is the first to report the effects of usual antimicrobial treatments on the microbiome and resistome of long-term care facility residents.

Transmission of antimicrobial resistance in the gut microbiome of gregarious cockroaches: the importance of interaction between antibiotic exposed and non-exposed populations.

Antimicrobial resistance (AMR) is a major global health concern, further complicated by its spread via the microbiome bacterial members. While mathematical models discuss AMR transmission through the symbiotic microbiome, experimental studies are scarce. Herein, we used a gregarious cockroach, Pycnoscelus surinamensis, as an in vivo animal model for AMR transmission investigations. We explored whether the effect of antimicrobial treatment is detectable with metagenomic sequencing, and whether AMR genes can be spread and established in unchallenged (not treated with antibiotics) individuals following contact with treated donors, and under various frequencies of interaction. Gut and soil substrate microbiomes were investigated by metagenomic sequencing for bacterial community composition and resistome profiling. We found that tetracycline treatment altered the treated gut microbiome by decreasing bacterial diversity and increasing the abundance of tetracycline resistance genes. Untreated cockroaches that interacted with treated donors also had elevated tetracycline resistance. The levels of resistance differed depending on the magnitude and frequency of donor transfer. Additionally, treated donors showed signs of microbiome recovery due to their interaction with the untreated ones. Similar patterns were also recorded in the soil substrate microbiomes. Our results shed light on how interacting microbiomes facilitate AMR gene transmission to previously unchallenged hosts, a dynamic influenced by the interaction frequencies, using an in vivo model to validate theoretical AMR transmission models.IMPORTANCEAntimicrobial resistance is a rising threat to human and animal health. The spread of resistance through the transmission of the symbiotic gut microbiome is of concern and has been explored in theoretical modeling studies. In this study, we employ gregarious insect populations to examine the emergence and transmission of antimicrobial resistance in vivo and validate modeling hypotheses. We find that antimicrobial treatment increases the levels of resistance in treated populations. Most importantly, we show that resistance increased in untreated populations after interacting with the treated ones. The level of resistance transmission was affected by the magnitude and frequency of population mixing. Our results highlight the importance of microbial transmission in the spread of antimicrobial resistance.

Optimizing a high-sensitivity NanoLuc-based bioluminescence system for in vivo evaluation of antimicrobial treatment.

Focal and systemic infections are serious threats to human health. Preclinical models enable the development of new drugs and therapeutic regimens. In vivo, animal bioluminescence (BL) imaging has been used with bacterial reporter strains to evaluate antimicrobial treatment effects. However, high-sensitivity bioluminescent systems are required because of the limited tissue penetration and low brightness of the BL signals of existing approaches. Here, we report that NanoLuc (Nluc) showed better performance than LuxCDABE in bacteria. However, the retention rate of plasmid constructs in bacteria was low. To construct stable Staphylococcus aureus reporter strains, a partner protein enolase (Eno) was identified by screening of S. aureus strain USA300 for fusion expression of Nluc-based luciferases, including Nluc, Teluc, and Antares2. Different substrates, such as hydrofurimazine (HFZ), furimazine (FUR), and diphenylterazine (DTZ), were used to optimize a stable reporter strain/substrate pair for BL imaging. S. aureus USA300/Eno-Antares2/HFZ produced the highest number of photons of orange-red light in vitro and enabled sensitive BL tracking of S. aureus in vivo, with sensitivities of approximately 10 CFU from mouse skin and 750 CFU from mouse kidneys. USA300/Eno-Antares2/HFZ was a powerful combination based on the longitudinal evaluation of the therapeutic efficacy of antibiotics. The optimized S. aureus Eno-Antares2/HFZ pair provides a technological advancement for the in vivo evaluation of antimicrobial treatment.

Detection of multidrug resistant Vibrio parahaemolyticus and anti-Vibrio Streptomyces sp. MUM 178J

The growing global population has increased the demand for seafood, making the aquaculture industry a vital food source. However, climate change has negatively impacted the industry as natural inhabitants of aquatic environments such as Vibrio parahaemolyticus are thriving in the warming waters. These foodborne pathogens can cause disease in marine animals, resulting in lowered production rates and substantial economic losses. V. parahaemolyticus is transmitted from these marine animals in aquaculture to humans via raw or undercooked seafood, resulting in gastroenteritis outbreaks. In addition, the extensive use of antibiotics in aquaculture to treat infections within marine animals has led to the development of multidrug-resistant (MDR) V. parahaemolyticus, which threatens the effectiveness of antimicrobial treatments. Thus, it is vital to explore the alternatives of antibiotics in aquaculture to manage the spread of antibiotic resistance. This study aimed to investigate the prevalence of MDR V. parahaemolyticus to provide insight into the current antibiotic resistance patterns of this pathogen and to determine potential anti-Vibrio properties of Streptomyces MUM 178J which was previously isolated from the soils of a mangrove forest in Sarawak, Malaysia. Colony morphology and toxR-assay indicated that all samples tested positive for V. parahaemolyticus. Further identification with genomic analyses confirmed that 64% (64/100) of the isolates were V. parahaemolyticus. The multiple antibiotic resistance index (MAR) of the isolates ranged between 0.07 and 0.57, with 81% (52/64) of the isolates resistant to more than one antibiotic. The isolates were most resistant to ampicillin (98.4%), followed by ceftazidime (53.1%). In contrast, the isolates were highly susceptible to nalidixic acid (98.4%), tetracycline (93.8%), and sulfamethoxazole/trimethoprim (90.6%). They also demonstrated susceptibilities of 89.1% to levofloxacin, oxytetracycline, and gentamicin. Streptomyces sp. MUM 178J exhibited antagonistic effects on select V. parahaemolyticus strain, RP0132, with a minimum inhibitory concentration of 12.5 mg/mL and a minimum bactericidal concentration of 50 mg/mL.

Comparative meta-analysis of antimicrobial resistance from different food sources along with one health approach in the Egypt and UK

BackgroundAntimicrobial resistance (AMR) is a critical global issue that poses significant threats to human health, animal welfare, and the environment. With the increasing emergence of resistant microorganisms, the effectiveness of current antimicrobial medicines against common infections is diminishing. This study aims to conduct a competitive meta-analysis of surveillance data on resistant microorganisms and their antimicrobial resistance patterns in two countries, Egypt and the United Kingdom (UK).MethodsData for this study were obtained from published reports spanning the period from 2013 to 2022. In Egypt and the UK, a total of 9,751 and 10,602 food samples were analyzed, respectively. Among these samples, 3,205 (32.87%) in Egypt and 4,447 (41.94%) in the UK were found to contain AMR bacteria.ResultsIn Egypt, the predominant resistance was observed against β-lactam and aminoglycosides, while in the United Kingdom, most isolates exhibited resistance to tetracycline and β-lactam. The findings from the analysis underscore the increasing prevalence of AMR in certain microorganisms, raising concerns about the development of multidrug resistance.ConclusionThis meta-analysis sheds light on the escalating AMR problem associated with certain microorganisms that pose a higher risk of multidrug resistance development. The significance of implementing One Health AMR surveillance is emphasized to bridge knowledge gaps and facilitate accurate AMR risk assessments, ensuring consumer safety. Urgent actions are needed on a global scale to combat AMR and preserve the effectiveness of antimicrobial treatments for the well-being of all living beings.

High burden of ESBL and carbapenemase-producing gram-negative bacteria in bloodstream infection patients at a tertiary care hospital in Addis Ababa, Ethiopia.

Bloodstream infection due to beta-lactamase and carbapenemase-producing gram-negative bacteria poses a substantial challenge to the effectiveness of antimicrobial treatments. Therefore, this study aimed to investigate the magnitude of beta-lactamase, carbapenemase-producing gram-negative bacteria, and associated risk factors of bloodstream infections in patients at a tertiary care hospital, in Addis Ababa, Ethiopia. An institutional-based cross-sectional study was conducted with convenience sampling techniques from September 2018 to March 2019. Blood cultures were analyzed from 1486 bloodstream infection suspected patients across all age groups. The blood sample was collected using two BacT/ALERT blood culture bottles for each patient. Gram stain, colony characteristics, and conventional biochemical tests were used to classify the gram-negative bacteria at the species level. Antimicrobial susceptibility testing was carried out to screen beta-lactam and carbapenem drug-resistant bacteria. The E-test was conducted for extended-spectrum-beta-lactamase and AmpC-beta-lactamase-producers. A modified and EDTA-modified carbapenem inactivation method was conducted for carbapenemase and metallo-beta-lactamases producers. Data collected using structured questionnaires and medical records were reviewed, encoded, and cleaned using EpiData V3.1. software. The cleaned data were exported and analyzed using SPSS version 24 software. Descriptive statistics and multivariate logistic registration models were used to describe and assess factors associated with acquiring drug-resistant bacteria infection. A p-value <0.05 was considered statistically significant. Among 1486 samples, 231 gram-negative bacteria were identified; of these, 195(84.4%) produce drug-hydrolyzing enzymes, and 31(13.4%) produce more than one drug-hydrolyzing enzyme. We found 54.0% and 25.7% of the gram-negative bacteria to be extended-spectrum-beta-lactamase and carbapenemase-producing, respectively. The extended-spectrum-beta-lactamase plus AmpC-beta-lactamase-producing bacteria account for 6.9%. Among the different isolates Klebsiella pneumonia 83(36.7%) was the highest drug-hydrolyzing enzyme-producing bacteria. Acinetobacter spp 25(53.2%) was the most carbapenemase producer. Extended-spectrum-beta-lactamase and carbapenemase-producing bacteria were high in this study. A significant association between age groups and extended-spectrum-beta-lactamase producer bacterial infection was seen, with a high prevalence in neonates (p = <0.001). Carbapenemase showed a significant association with patients admitted to the intensive care unit (p = 0.008), general surgery (p = 0.001), and surgical intensive care unit (p = 0.007) departments. Delivery of neonates by caesarean section, and insertion of medical instruments into the body were exposing factors for carbapenem-resistant bacterial infection. Chronic illnesses were associated with an extended-spectrum-beta-lactamase-producing bacterial infection. Klebsiella pneumonia and Acinetobacter species showed the greatest rates of extensively drug-resistant (37.3%) and pan-drug-resistance (76.5%), respectively. According to the results of this study, the pan-drug-resistance prevalence was found to be alarming. Gram-negative bacteria were the main pathogens responsible for drug-resistant bloodstream infections. A high percentage of extended-spectrum-beta-lactamase and carbapenemase-producer bacteria were found in this study. Neonates were more susceptible to extended-spectrum-beta-lactamase and AmpC-beta-lactamase-producer bacteria. Patients in general surgery, caesarean section delivery, and intensive care unit were more susceptible to carbapenemase-producer bacteria. The suction machines, intravenous lines, and drainage tubes play an important role in the transmission of carbapenemase and metallo-beta-lactamase-producing bacteria. The hospital management and other stakeholders should work on infection prevention protocol implementation. Moreover, special attention should be given to all types of Klebsiella pneumoniae and pan-drug resistance Acinetobacter spp transmission dynamics, drug resistance genes, and virulence factors.

Indicators of immune status in women with different recurrence rates of nonspecific inflammatory diseases of the genital organs

Non-specific inflammatory diseases of the female genital organs (NIDFGO) are an important problem of modern gynecology due to their high frequency in the population, the tendency to frequent recurrences, and many cases of resistance to recommended antimicrobial and anti-inflammatory drugs. Aim: to study indicators of immune status in women with different recurrence rates of NIDFGO and biomarkers of recurrences to improve potential therapeutic approaches and prevent recurrences in the further. Materials and methods. A prospective single-center controlled non-randomized clinical study was conducted with the participation of 98 adult women. Out of them, 80 patients with NIDFGO had one-year recurrence rate of 1, 2–3, 4 or more events, and 18 age-matched women without NIDFGO were assigned to the control group. Immunogram and hemogram were performed for all study participants using standardized methods. Statistical analysis of the results was performed using IBM SPSS 23 statistical package software. Results. The mean serum concentration of IgE in patients with frequent relapses was 3 times (p &lt; 0.05) lower than that in women with only one recurrence, 2.6 times (p &lt; 0.05) lower than that in patients with medium recurrence rate, and 3.4 times (p &lt; 0.05) less than in the control. In women with frequent recurrences, the mean relative number of blood NKT cells was 3.5 times (p &lt; 0.05) less than that in patients with only one recurrence, 2.3 times (p &lt; 0.05) less than that in persons with medium recurrence rate, and 3 times (p &lt; 0.05) less as compared to women of the control group. Conclusions. Selective deficiencies of IgE and NKT cells in women with NIDFGO are factors that lead to a higher frequency of disease exacerbations per year. T he development and clinical approval of immunotherapeutic approaches to compensate for deficiencies of IgE and NKT cells in women with NIDFGO will contribute to the imposition of immune control over the inflammatory process, increase the effectiveness of antimicrobial treatment, resulting in a decrease in the recurrence rate.

Influence of surface characteristics of implant materials on MRSA biofilm formation and effects of antimicrobial treatment.

One of the main causes of treatment failure in bacterial prosthetic joint infections (PJI) is biofilm formation. The topography of the biofilm may be associated with susceptibility to antimicrobial treatment. The aims of this study were to assess differences in topography of biofilms on different implant materials and the correlation thereof with susceptibility to antimicrobial treatment. Methicillin-resistant Staphylococcus aureus (MRSA) 7-day mature biofilms were generated on disks made from titanium alloys (Ti-6Al-7Nb and Ti-6Al-4V), synthetic polymer and orthopedic bone cement, commonly used in implant surgery. The surface topography of these implant materials and the biofilms cultured on them was assessed using atomic force microscopy. This provided detailed images, as well as average roughness (Ra) and peak-to-valley roughness (Rt) values in nanometers, of the biofilm and the material surfaces. Bacterial counts within biofilms were assessed microbiologically. Antimicrobial treatment of biofilms was performed by 24-h exposure to the combination of rifampicin and ciprofloxacin in concentrations of 1-, 5- and 10-times the minimal bactericidal concentration (MBC). Finally, treatment-induced differences in bacterial loads and their correlation with biofilm surface parameters were assessed. The biofilm surfaces on titanium alloys Ti-6Al-7Nb (Ra = 186 nm) and Ti-6Al-4V (Ra = 270 nm) were less rough than those of biofilms on silicone (Ra = 636 nm). The highest roughness was observed for biofilms on orthopedic bone cement with an Ra of 1,551 nm. Interestingly, the roughness parameters of the titanium alloys themselves were lower than the value for silicone, whereas the surface of the bone cement was the roughest. Treatment with 1- and 5-times the MBC of antibiotics resulted in inter-material differences in colony forming units (CFU) counts, ultimately showing comparable reductions of 2.4-3.0 log CFU/mL at the highest tested concentration. No significant differences in bacterial loads within MRSA biofilms were observed between the various implant materials, upon exposure to increasing concentrations of antibiotics. The surface parameters of MRSA biofilms were determined by those of the implant materials on which they were formed. The antibiotic susceptibility of MRSA biofilms on the various tested implant materials did not differ, indicating that the efficacy of antibiotics was not affected by the roughness of the biofilm.

Effects of Intramammary Antimicrobial Treatment on the Milk Microbiota Composition in Mild Clinical Bovine Mastitis Caused by Gram-Positive Bacteria

The purpose of this study was to clarify the effects of antimicrobial treatment for mild mastitis caused by Gram-positive bacteria on the milk microbiota in dairy cattle. Sixteen quarters of sixteen cows with mild clinical mastitis from the same herd were included in the study. On the day of onset (day 0), the cows were randomly allocated to a no-treatment (NT; n = 10) group or an intramammary antimicrobial treatment (AMT) group that received AMT starting on day 0 (AMT-AMT group; n = 6). The next day (day 1), the cows in the NT group were randomly allocated into an NT group (NT-NT group; n = 3) that received no treatment or an AMT group that received AMT starting on day 1 (NT-AMT group; n = 7). Milk samples were collected on days 0, 1, 3 and 7, and the milk microbiota of each sample was comprehensively analyzed via 16S rRNA gene amplicon sequencing of the milk DNA. During the treatment period, the milk microbiota of the NT-NT group did not change, but those of the NT-AMT and AMT-AMT groups changed significantly on days three and seven. Thus, the use of antimicrobials for mild mastitis caused by Gram-positive bacteria changes the milk microbiota composition.

Клинико-эпидемиологическая и лабораторная характеристика пищевой вспышки сальмонеллеза

Among bacterial intestinal infections, salmonellosis occupies one of the leading places. The purpose to study the clinical, epidemiological and laboratory features of a food outbreak of salmonellosis. Material and methods. A retrospective analysis of 29 medical records of patients from a food outbreak of salmonellosis hospitalized in the Republican Clinical Infectious Diseases Hospital of Kazan in September 2021. Results. The likely transmission factors for Salmonellosis were poached egg and/or lightly salted salmon. Young females predominated (83%) among patients. The disease proceeded according to the gastroenteric variant (69%) of moderate severity (96.6%) with a favorable outcome (100%). The incidence of colitis syndrome was 31%. Among the biochemical parameters, high levels of CRP (161.97 (108.54) mg/l) attracted attention, reaching values characteristic of a severe bacterial infection. In bacteriological examination of faeces and/or vomit, Salmonella enteritidis was isolated from all patients. The isolated strains of S. enteritidis were sensitive to ampicillin, cefepime, ceftriaxone, chloramphenicol, salmonella bacteriophage, 80% of the isolates were resistant to pefloxacin and 40% to co-trimoxazole. Conclusions. A persistent increase in CRP can be used at the initial stage of differential diagnosis of etiologically different types of diarrheas to decide on the tactics of treating patients with infectious diarrhea. In order to maximize the effectiveness of antimicrobial treatment of salmonellosis, it is necessary to focus on regional antibiotic susceptibility profiles.

EFFECTIVENESS OF THE ANTIMICROBIAL TREATMENT OF TEXTILE MATERIALS FOR USE AT HOME AND IN PUBLIC SPACES

The purpose of the work is to develop an antimicrobial composition and study the effectiveness of antimicrobial treatment of textile materials. Methodology. Polyhexamethylene guanidine chloride with bio-based antimicrobial preparations were used as the objects of the study as effective safe antimicrobial agents. The treatment of cotton fabric was carried out by impregnation with an aqueous solution of polymer and polyhexamethylene guanidine chloride and bio-based antimicrobial preparations in a finishing bath, followed by drying and thermal fixation. Changes in the structural parameters of the acrylic polymer and the number of crosslinks in the bulk of the polymer formation were determined from the property of crosslinked polymer systems to swell in solvents to a limited extent. Examination of the antimicrobial effect of textile materials was carried out by analyzing the diffusion of the fabric disk on agar after treatment with the antimicrobial composition and after washing. To determine the effectiveness of the antimicrobial action of bio-based preparations, one of the representatives of the wound microflora, the gram-positive bacterium Staphylococcus pyoqenes from the Ukrainian collection of microorganisms, was used as a test culture. Findings. The results of the study of textile materials after treatment with bio-based antimicrobial preparations and polyhexamethylene guanidine chloride are presented. An increase in the resistance of the antimicrobial effect to washing was achieved by introducing an acrylic polymer into the finishing composition, the structure formation of which was evaluated by the amount of the acetone-insoluble fraction of polymer films during extraction in solvents. The results of the study showed that the introduction of antimicrobial agents into the polymer composition increases the degree of crosslinking of the polymer film due to the use of polyhexamethylene guanidine chloride. The effectiveness of the antimicrobial action of bio-based preparations has been proven by the results of a study on a test culture of a gram-positive bacterium Staphylococcus pyoqenes, which is confirmed by the appearance of a zone of inhibition of the microorganism around the studied fabric sample. Studies using the settle plate method showed that all fabric samples treated with the antibacterial composition are characterized by a pronounced zone of microflora growth inhibition. Originality. It has been proven that an acrylic polymer-based finishing composition containing polyhexamethylene guanidine chloride and bio-based preparations provides an antimicrobial effect to a textile material and will improve the wash resistance of the antimicrobial effect by increasing the degree of crosslinking of the acrylic polymer. Practical value. The obtained results of the experiment are of practical importance for the development of new finishing compositions for imparting antimicrobial properties to textile materials.