Epidemiological Significance Research Articles

Monitoring of Klebsiella pneumoniae as one of the criteria of microecological characterization of a water body

Introduction. Representatives of the family Enterobacteriaceae are ubiquitous in the environment, causing severe, including opportunistic diseases in immunocompromised individuals. The occurrence of antibiotic-sensitive bacteria of the Klebsiella genus within the recreational zone of a water body is potent of posing an epidemiologic danger to the inhabitants of the settlement. 
 Materials and Methods. Water samples from the surface aquifers of the Don and Temernik rivers of Rostov-on-Don served as the material for the study. The sensitivity of isolates of Kl. pneumoniae isolates to fourteen antibacterial preparations were investigated by disk-diffusion method in accordance with the requirements of MUK 4.2.1980-04 and EUCAST v. 13.0 (2023). 13.0 (2023). Carbapenemase genes VIM, IMP, NDM, KPC, OXA-48, NDM were determined using commercial diagnostic kits AmpliSense MDR MBL-FL, AmpliSense MDR KPC/OXA-48-FL, AmpliSense MDR Ab-OXA-FL.
 Results. In 2022, 247 isolates of Klebsiella pneumoniae were isolated in 14 biotopes of water bodies of Rostov-on-Don. Biotopes of epidemiological significance were identified with the presence of antibiotic resistance genes in 28 isolates isolated above and below the sewage discharge site (sampling point #1 and #5) and strains isolated from the mouth of the Temernik River (sampling point #14). Phenotype of multidrug-resistant (MDR) in point No. 1 possessed 22%, point No. 5 – 26.9%, point No. 14 – 26%; phenotype of extreme drug resistance (XDR) in point No. 1 possessed 11.1 %, point No. 5 – 15.3%, point No. 14 – 13%; phenotype of pan-drug-resistant (PDR) in point No. 1 did not possess, point No. 5 – 3.8%, point No. 14 – 4.3%.
 Limitations. A limitation of the study is related to the location of water sampling from the river. Don and R. Temernik on the territory of Rostov-on-Don, covering from March to November 2022. In this article, we limited ourselves to sanitary-bacteriological and molecular genetic analysis.
 Conclusion. The detection of PDR, XDR, and MDR antibiotic-resistant phenotypes of Klebsiella pneumoniae, as well as the detection of resistance genes, indicates to an increased risk of water-associated acute intestinal infections, especially in immunosuppressed individuals.

Evaluation of the toxicogenetic potential of visceral leishmaniasis in naturally infected dogs and salivary samples for definitive disease diagnosis

Visceral leishmaniasis is an infectious and zoonotic disease caused by the protozoan Leishmania infantum chagasi, transmitted through the bite of the sandfly Lutzomyia longipalpis, with dogs serving as the primary reservoir. Given the increasing spread of this disease in dogs and its epidemiological and public health significance, this study aimed to investigate whether salivary samples from naturally infected dogs could serve as a diagnostic tool, attempting to replace invasive conventional methods. Additionally, the study analyzed the potential toxicogenetic effects of the disease. Ten adult dogs, both males and females, intact and neutered, of mixed breed, from Rifaina (SP) and attended at the Veterinary Hospital of the University of Franca, were included. These dogs exhibited various clinical signs suggestive of visceral leishmaniasis, with five of them confirmed through serological and parasitological examinations. Salivary samples were collected using sterile swabs from the five seropositive dogs, placed on glass slides, and stained with hematoxylin-eosin for subsequent analysis of amastigote forms of the protozoan using bright-field microscopy; the results were descriptive. Furthermore, bone marrow samples from the sternum were collected from the five seropositive dogs and compared with those from the five seronegative dogs to investigate the toxicogenetic potential of the disease through the micronucleus test. To assess possible genotoxicity, each slide made from bone marrow was analyzed for 2000 immature erythrocytes (IE), totaling 4000 IE/animal, and those containing micronuclei (MN) were identified (IE-MN). Cytotoxicity was determined by analyzing 1000 erythrocytes/slide, totaling 2000 erythrocytes/dog, and subsequently calculating the ratio of IE/IE+NCE (normochromatic erythrocytes). Toxicogenetic results of seropositive dogs were compared with seronegative dogs and statistically verified by simple analysis of variance (ANOVA). The protozoan Leishmania was not detected in any of the salivary samples from seropositive dogs. The mean frequency of IE-MN in seropositive dogs was statistically higher compared to seronegative dogs (p<0.0001), indicating the genotoxicity of the disease. In two of the five seropositive dogs, a decrease in erythrocyte production suggested cytotoxicity of the disease. Given the established methodology, it can be inferred that simple saliva analysis, without more specific assays, does not detect amastigote forms of the protozoan in dogs seropositive for visceral leishmaniasis and should not replace established diagnostic methods. Additionally, the micronucleus test suggested the genotoxicity and cytotoxicity of the disease.

Spatiotemporal heterogeneity and potential drivers of human tick-borne encephalitis in the south of Russian Far East

The south of the Russian Far East is distinguished by diversity of natural conditions for the presence of vectors and circulation of pathogens, primarily tick-borne infections. Despite the relatively low proportion of tick-borne encephalitis in the structure of tick-borne infections and the rather low incidence rate compared to other Russian regions, the disease here has epidemiological significance, which is associated with its severe course. Therefore, it is important to identify local areas of greatest epidemic manifestation of the disease and potential drivers influencing the spread of tick-borne encephalitis. This study uses data on population incidence in the municipal districts of Khabarovsk Krai, Amur Oblast, Jewish Autonomous Oblast and Zabaikalsky Krai between 2000 and 2020. Based on Kulldorf spatial scanning statistics, a temporally stable cluster of virus circulation in the population in the southwest of Zabaikalsky Krai was identified, which existed during 2009-2018. Regression modeling using zero-inflated negative binomial regression based on a set of environmental and socio-economic predictors allowed to identify variables determining the probability of infection: the share of forest, the amount of precipitation in the warm period, population density, as well as variables reflecting population employment and socio-economic well-being. Despite the fact that tick-borne encephalitis is a natural focal disease and may be characterized by natural periods of increased incidence, the influence of the social component can have a strong impact on the epidemiological manifestation. The identified spatio-temporal differences within the study region and potential drivers must be taken into account when developing a set of preventive measures.

Epidemiology and clinical significance of carbapenemases in Australia: a narrative review.

Carbapenemase-producing gram-negative bacteria (CP-GNB) infections threaten public health with high mortality, morbidity and treatment costs. Although frequencies remain low in Australia (total number of CP-GNB infections reported was 907 in 2022), blaIMP-4 has established low levels of endemicity in many states. Imipenemase metallo-β-lactamase types alone accounted for more than half of all carbapenemases in carbapenemase-producing Enterobacterales isolates in Australia, particularly in Enterobacter cloacae complex. New Delhi metallo-β-lactamase constitutes almost 25% of all carbapenemases in Australia and was identified predominantly in Escherichia coli. The OXA-48-like carbapenemases include almost 10% of all carbapenemases and are mainly seen in Klebsiella pneumoniae and E. coli. Although K. pneumoniae carbapenemase-type carbapenemases are rare in Australia, some local outbreaks have occurred. Most carbapenem-resistant (CR) Pseudomonas aeruginosa strains in Australia do not produce carbapenemases. Finally, OXA-23-like carbapenemases are overwhelmingly positive in CR-Acinetobacter baumannii strains in Australia. Treatment of CR-GNB infections challenges physicians. Of 10 new antibiotics active against at least some CR-GNB infections that are approved by the USFood and Drug Administration, just three are approved for use in Australia. In this context, there is still an unmet need for novel antibacterials that can be used for the treatmentof CR-GNB infections in Australia, as well as a pressing requirement for new mechanisms to 'de-link' antibiotic sales from their availability. In this narrative review, we aim to overview the epidemiology and clinical significance of carbapenem resistance in Australia as it pertains to Enterobacterales, P. aeruginosa and A. baumannii.

Assessment of the Current State of the Hissar High-Mountain Natural Plague Focus in the Republic of Tajikistan

The review is devoted to discussing the results of survey in the Hissar high-mountain natural plague focus on the territory of the Republic of Tajikistan in 2015–2023. Regular examination of the focus was carried out in 1970–1991. According to its results, the main carrier of the plague pathogen was the juniper vole, in the population of which a strain of the non-main subspecies central asiatica (0.PE4) of Hissar biovar (0.PE4h) was steadily circulating, the strain considered avirulent for humans. During that period, 853 strains were isolated in the focus, of which 799 (93.7%) were from the juniper vole and its fleas. Secondary carriers – the silver vole, the pygmy wood mouse, and the gray hamster – were rarely involved in epizootics. The red marmot, which has epidemiological significance due to its hunting by the local population, occupies a special position in the focus. Socio-political phenomena at the end of the 20th – early 21st century caused a long break in the work of the Tajik Plague Control Station. In 2008, the Station was transformed into the Republican Center for Combating Quarantine Diseases under the Ministry of Health and Social Protection of the Population of the Republic of Tajikistan. In 2015, studies were resumed, but carried out on a small scale. In 2021–2023, epizootiological monitoring in the Hissar focus was performed jointly with Russian specialists with the testing of field material samples for plague and other natural-focal infections. Currently, against the background of low numbers and population density of small mammals and their blood-sucking ectoparasites – potential carriers and vectors of zoonoses – the circulation of agents of plague, tularemia, pseudotuberculosis, tick-borne viral encephalitis, Ixodidae tick-borne borreliosis, human granulocytic anaplasmosis, human monocytic ehrlichiosis has not been registered. Markers (DNA) of causative agents of leptospirosis and intestinal yersiniosis have been identified. Joint Tajik-Russian cooperation on issues of ensuring the epidemiological well-being of the population of the Republic of Tajikistan must be continued.

Epidemiology and Prognostic Significance of Cough in Fibrotic Interstitial Lung Disease.

Rationale: Cough is a key symptom in patients with fibrotic interstitial lung disease (ILD). Objectives: This study evaluated the prevalence, longitudinal change, associations, and prognostic significance of cough severity in patients with fibrotic ILD. Methods: We included consecutive patients with idiopathic pulmonary fibrosis (IPF) and non-IPF fibrotic ILD who completed the 100-mm Cough Severity Visual Analog Scale from the prospective multicenter Canadian Registry for Pulmonary Fibrosis. Baseline cough severity and associations with patient demographics and clinical factors were determined. Relationships between baseline cough severity and health outcomes were evaluated. Measurements and Main Results: Patients with IPF (n = 1,061) had higher median baseline cough severity than those with non-IPF fibrotic ILD (n = 2,825) (24 vs. 20 mm; P < 0.001), with worse cough associated with gastroesophageal reflux disease for both cohorts. Worse cough severity was independently associated with worse health-related quality of life at baseline, larger annualized decline in DlCO, development of disease progression, and reduced transplant-free survival in both IPF and non-IPF fibrotic ILD cohorts. The IPF cohort (2.2 mm; 95% confidence interval, 1.6-2.9 mm) had larger annualized increments in cough severity than the non-IPF fibrotic ILD cohort (1.1 mm; 95% confidence interval, 0.8-1.4 mm; P = 0.004). There was no difference in worsening cough over time comparing those receiving and not receiving ILD-targeted therapy or with and without lung function decline. Conclusions: Cough is common in patients with IPF and non-IPF fibrotic ILD, with increasing cough severity over time irrespective of ILD-targeted therapy. Patient-reported cough severity has prognostic implications on health-related quality of life, disease progression, and survival in fibrotic ILD.

Human Herpes Virus-6 (HHV-6) Reactivation after Hematopoietic Cell Transplant and Chimeric Antigen Receptor (CAR)- T Cell Therapy: A Shifting Landscape.

HHV-6B reactivation affects approximately half of all allogeneic hematopoietic cell transplant (HCT) recipients. HHV-6B is the most frequent infectious cause of encephalitis following HCT and is associated with pleiotropic manifestations in this setting, including graft-versus-host disease, myelosuppression, pneumonitis, and CMV reactivation, although the causal link is not always clear. When the virus inserts its genome in chromosomes of germ cells, the chromosomally integrated form (ciHHV6) is inherited by offspring. The condition of ciHHV6 is characterized by the persistent detection of HHV-6 DNA, often confounding diagnosis of reactivation and disease-this has also been associated with adverse outcomes. Recent changes in clinical practice in the field of cellular therapies, including a wider use of post-HCT cyclophosphamide, the advent of letermovir for CMV prophylaxis, and the rapid expansion of novel cellular therapies require contemporary epidemiological studies to determine the pathogenic role and spectrum of disease of HHV-6B in the current era. Research into the epidemiology and clinical significance of HHV-6B in chimeric antigen receptor T cell (CAR-T cell) therapy recipients is in its infancy. No controlled trials have determined the optimal treatment for HHV-6B. Treatment is reserved for end-organ disease, and the choice of antiviral agent is influenced by expected toxicities. Virus-specific T cells may provide a novel, less toxic therapeutic modality but is more logistically challenging. Preventive strategies are hindered by the high toxicity of current antivirals. Ongoing study is needed to keep up with the evolving epidemiology and impact of HHV-6 in diverse and expanding immunocompromised patient populations.

Prevalence and clinical outcomes of isolated or combined moderate to severe mitral and tricuspid regurgitation in patients with cardiac amyloidosis.

Evidence on the epidemiology and prognostic significance of mitral regurgitation (MR) and tricuspid regurgitation (TR) in patients with cardiac amyloidosis (CA) is scarce. Overall, 538 patients with either transthyretin (ATTR, n = 359) or immunoglobulin light-chain (AL, n = 179) CA were included at three Italian referral centres. Patients were stratified according to isolated or combined moderate/severe MR and TR. Overall, 240 patients (44.6%) had no significant MR/TR, 112 (20.8%) isolated MR, 66 (12.3%) isolated TR, and 120 (22.3%) combined MR/TR. The most common aetiologies were atrial functional MR, followed by primary infiltrative MR, and secondary TR due to right ventricular (RV) overload followed by atrial functional TR. Patients with isolated or combined MR/TR had a more frequent history of heart failure (HF) hospitalization and atrial fibrillation, worse symptoms, and higher levels of NT-proBNP as compared to those without MR/TR. They also presented more severe atrial enlargement, atrial peak longitudinal strain impairment, left ventricular (LV) and RV systolic dysfunction, and higher pulmonary artery systolic pressures. TR carried the most advanced features. After adjustment for age, sex, CA subtypes, laboratory, and echocardiographic markers of CA severity, isolated TR and combined MR/TR were independently associated with an increased risk of all-cause death or worsening HF events, compared to no significant MR/TR [adjusted HR 2.75 (1.78-4.24) and 2.31 (1.44-3.70), respectively]. In a large cohort of patients with CA, MR, and TR were common. Isolated TR and combined MR/TR were associated with worse prognosis regardless of CA aetiology, LV, and RV function, with TR carrying the highest risk.

Direct Evidence of Powassan Virus Vertical Transmission in Ixodes scapularis in Nature.

Powassan virus (POWV) is a tick-borne flavivirus endemic in North America and Russia. Experimental infections with POWV have confirmed horizontal, transstadial, vertical, and cofeeding transmission routes for potential virus maintenance. In the field, vertical transmission has never been observed. During New York State tick-borne pathogen surveillance, POWV RNA and/or infectious POWV was detected in five pools of questing Ixodes scapularis larvae. Additionally, engorged female I. scapularis adults were collected from hunter-harvested white-tailed deer (Odocoileus virginianus) in a region with relatively high tick infection rates of POWV and allowed to oviposit under laboratory conditions. POWV RNA was detected in three female adult husks and one pool of larvae from a positive female. Infectious virus was isolated from all three RNA-positive females and the single positive larval pool. The detection of RNA and infectious virus in unfed questing larvae from the field and larvae from replete females collected from the primary tick host implicates vertical transmission as a potential mechanism for the maintenance of POWV in I. scapularis in nature, and elucidates the potential epidemiological significance of larval ticks in the transmission of POWV to humans.

Role of ixodid ticks in tick-borne pathogen spread and circulation in the Belarusian Lakeland

Results of ixodid tick analysis for their ecological, epizootological and epidemiological significance for tick-borne pathogen spread across the Belarusian Lakeland are presented. The ticks were collected in publicly accessible areas of the Vitebsk Raion in April – November 2022: 8 routes were tracked, 18 flag-km were passed, 529 tick specimens were collected, including 350 imago ticks and 179 nymph ticks. The ixodid tick genus and species were determined using N. A. Filippova’s ixodid tick determinator. All caught ticks were tested for Borrelia spp., Anaplasma spp. (Ehrlichia spp.), Babesia spp. and Tick-borne encephalitis virus genetic materials with real-time polymerase chain reaction using the reagent kit for nucleic acid extraction from environmental samples in accordance with the manufacturer’s instruc­tions. The specimens were grouped in accordance with the MG 3.1.1027-01 “Collection, recording and preparation for laboratory tests of blood-sucking arthropods being vectors of natural focal infections”; therewith, one specimen includes only one tick. Differences in the numbers of ixodid ticks and the occurrence of genetic markers of tick-borne pathogens in them were found to be associated with ecological characteristics of the examined territories. The following epidemically and epizootically significant ticks contributing to transmissible infection and invasion spread were found in the Belarusian Lakeland: ticks of Ixodes and Dermacentor genera; their frequency index was 70.1 and 29.9%, respectively. Tick-transmitted pathogen prevalence rate in the examined territories of the Vitebsk Raion was as follows: 61.7% for Borrelia spp., 25.8% for Anaplasma spp. (Ehrlichia spp.) and 25% for Babesia spp., mixed infections were found in 10.8% of the ticks. No tick-borne encephalitis virus genetic materials were found in the specimens. Total infection rate for ixodid ticks was 22.7%.

Characteristics of campylobacteriosis in the Arkhangelsk Region

In recent years, the incidence of campylobacteriosis in Russia has decreased significantly, but the Arkhangelsk Region is an area where the incidence of campylobacteriosis among all acute intestinal infections is increasing. According to the WHO, campylobacters make up 15 % of the etiological structure of diarrheal diseases in humans, which determines the epidemiological significance of this infection and reflects the urgency of the problem.

Tyrosine kinase inhibitor-induced hypothyroidism: mechanism and clinical implications.

Since the first experimentally proven tyrosine kinase inhibitor (TKI) imatinib was introduced in the clinical setting, TKIs have attracted widespread attention because of their remarkable therapeutic effects and improvement of survival rates. TKIs are small-molecule, multi-target, anti-cancer agents that target different tyrosine kinases and block downstream signaling. However, with in-depth research on TKI drugs, the adverse reactions-for example, thyroid dysfunction-have become a concern and thus have attracted the attention of numerous researchers. Thyroid dysfunction, especially hypothyroidism, that occurs in high incidence during TKI therapy has a close relationship with treatment efficacy, but the mechanism of TKI-induced thyroid dysfunction is obscure. This review discusses the epidemiology, possible mechanisms, and clinical significance of hypothyroidism in cancer patients treated with TKI.

Bifurcation analysis of a delayed stochastic HBV epidemic model: Cell-to-cell transmission

In the present study, we develop a model for hepatitis B virus (HBV) that integrates cell-to-cell transmission of the virus, CTL immunological response, delay effects, and the effect of fluctuating environmental noise. The inheritance randomness of the system shifting the system from a deterministic to another system consists of stochastic differential equations (SDEs). After model formulation, the dynamical aspects of the model are investigated by using the key threshold quantity R0. If the threshold value R0 is assumed less than unity, then it is proven that the solution trajectories are fluctuating around the disease-free state (DFS) of the associated deterministic model. The fluctuation of the trajectories around the DFS explains the phenomenon of extinction of the stochastic models. It is also proved that the trajectories of the SDE model oscillate around the endemic state of the underlying ODE system when R0s>1 explains the sure persistence theory of the proposed model. One notable finding of the present manuscript is the positive association between the fluctuating amplitude and the intensities of the white noises. This understanding can provide useful control tools for managing the worst dynamic(s) of the infection. The exact value of the parameter for time delay determines the stability of the model under consideration. By analyzing the time-delayed parameter, it was identified that the model is stable by keeping the value of the parameter below the crucial value that causes the Hopf bifurcation. This conclusion is supported by the numerical examples having epidemiological significance. Furthermore, the findings suggest that stochastic environmental disturbance can impact the spread of infectious illnesses. Notably, the high levels of noise can help to slow down the spread of epidemics in the population.

The results of entomological monitoring West Nile fever on the territory of the Crimean peninsula in the 2022 season

Objective: to evaluate the role of blood-sucking mosquitoes of various species living in the northern and central regions of the Crimean Peninsula in the transmission of West Nile virus (WNV).Materials and methods: the collection of bloodsucking mosquitoes was carried out in 7 administrative units of the Republic of Crimea with automatic traps and a vertical handheld vacuum cleaner from July 1 to August 5, 2022. The species composition of mosquitoes was determined visually using an MSP-1 stereomicroscope (option 22) using standard keys. Detection of WNV RNA in the samples was performed by RT-PCR. Mosquito infection levels and dominance index were calculated.Results: a common eudominant species for urban and rural biotopes of the surveyed areas was determined Ae. caspius, whose dominance index was 72.4% and 31.3%. Mosquitoes of the species Cx. modestus were the most numerous in rural biotopes (dominance index — 48.4%). The invasive species Ae. albopictus in the central part of the Crimean peninsula, which indicates the expansion of its habitat. Of 18.6 thousand mosquitoes of 12 species, merged in 693 samples, WNV RNA was detected in 14 samples (2.02%), 3 isolates of the pathogen were isolated. A high level of WNV infection of mosquitoes in urban biotopes was established, which amounted to 4.12%. WNV circulation was first confirmed in the northern part of Crimea (Krasnoperekopsky district).Conclusion: the epidemiological significance of mosquitoes of various species on the territory of the Crimean Peninsula has been determined. The data on the spread of WNV in the Republic of Crimea were supplemented, taking into account which the estimated zoning of the territory was carried out according to the degree of risk of infection with WNV. Recommendations are given to strengthen epidemiological surveillance and preventive measures.

Transmission Electronic Microscopy of Vibrio cholerae Biofilms on Chitin-Containing Substrates

Introduction. The evolutionary association of Vibrio cholerae with chitin provided resistance to stress and protection from predators. The most important mechanism that provided V. cholerae with the effectiveness of association with chitin is biofilm formation. The ability to form a biofilm in V. cholerae depends on the presence of a factor, toxin-corrected adhesion pili (TCP), which are synthesized by the tcp A-F genes. One of the key methods for studying biofilms is microscopy. It allows one to visualize the structural elements and study various parameters of biofilms and the effects of various factors on them. Aim. To determine the epidemiological significance of the biofilm-forming ability of toxigenic strains by their morphological characteristics on chitin-containing substrates. Study of structural differences in biofilms of Vibrio cholerae tcpA+– and tcpA– strains on chitin-containing substrates. Results. It has been shown that Vibrio cholerae tcpA+– and tcpA– strains are able to form biofilms on the surface of chitin-containing substrates. The intensity of biofilm formation is more pronounced in tcpA+ strains, because V. cholerae ctxA+ tcpA+ cells in the biofilm are predominantly singly located and the surface of the chitinous exoskeleton with which they are in contact is intact, V. cholerae ctxA– tcpA– cells form chains in the biofilm, which indicates division processes, and scattered chitin of the endocuticle indicates activity of metabolic processes. Conclusion. The strains of V. cholerae used in the work, regardless of the presence or absence of the ctx and tcp genes, form bioplecs on a chitin substrate. The indicator of biofilm formation in terms of the thickness of the biofilm matrix is higher in V. cholerae ctxA+ tcpA+ , in terms of the degree of degradation of the chitin substrate it is higher in V. cholerae ctxA– tcpA– .

Possibilities of Using Geoinformation Technologies in Epidemiological Surveillance of COVID-19 Infection at the Regional Level

Relevance. The spread of the new coronavirus infection throughout the world has led to expressed interest in studying, among other things, the patterns of territorial distribution of cases of the disease. Aim. To investigate the spatial distribution of cases of COVID-19 infection and develop proposals for the use of GIS technologies in the epidemiological supervision system for the new coronavirus infection at the regional level. Materials and methods. The study was conducted on the territory of the closed administrative- territorial entity of Zelenogorsk, Krasnoyarsk Territory. 4176 cases of COVID-19 infection were reported during the study period of 57 weeks (04/12/2020 to 06/18/2021). Each case of the disease was geocoded by the residence of the sick person using a projection coordinate system from the open data of the Open Street Map resource. The spatial distribution of COVID-19 cases was studied with geographic information system QGIS Desktop version 3.28.0. Spatial autocorrelation analysis was carried out using the Getis-Ord index. Results. During the application of GIS technologies, the density of distribution of COVID-19 infection cases was estimated, six zones with an average core density were discovered, the outbreaks in the northern part of the city had the greatest epidemiological significance. When assessing the clustering of cases within the specified territorial zones, eleven clusters were identified, three of which were characterized by the highest density of cases - 1210.1 cases per 1 sq. km, 1155.9 and 1116.7 cases per 1 sq. km. The Getis-Ord index value ranged from 0.00 to 2.576, the majority of cases was recorded in territorial clusters located in the northern part of the city. Conclusions. New knowledge obtained on the basis of modern GIS technologies about the presence of “hot spots” or clusters in the administrative territory will make the adjustment of preventive measures in micro-areas with a high prevalence of infection possible and develop strategies for more effective control of COVID-19 infection.

Характеристика генів інтегронів клінічних ізолятів Pseudomonas aeruginosa, які реалізують резистентність до антибіотиків та біоплівкоутворення цими штамами

Pseudomonas aeruginosa is a bacterium that holds significant clinical and epidemiological significance. It serves as the principal etiological cause of opportunistic infections in individuals with impaired immune systems. Integrons are known to have a notable impact on Gram-negative bacteria, particularly in the context of P. aeruginosa, a bacterium recognized for its ability to develop resistance to antimicrobial drugs. Aim. To systematically characterize and detect integron genes (intI, intII, intIII) with antibiotic-resistant and biofilm-forming capabilities in isolated P. aeruginosa. Methods. A total of 209 samples were collected from Al Yarmouk Teaching Hospital in Baghdad City, Iraq to isolate P. aeruginosa. The process of bacterial identification was carried out phenotypically and by biochemical tests. Antibiotic susceptibility was measured using the Vitek2 system. Biofilm quantification was done by the microtiter method. The PCR approach was employed to assess the presence of class 1, 2, and 3 integrons. Results. P. aeruginosa was identified in 83 isolates by using a combination of morphological and biochemical examinations where all isolates showed the ability to grow a selective medium on cetrimide agar for P. aeruginosa. The results also showed significant variances (p &lt; 0.05) among the percentage of a number of samples and isolated P. aeruginosa. The burn and wound infection scored the highest percentages (25% and 19%) based on the positivity of P. aeruginosa, whereas burn and ear sites scored the highest percentage (58% and 50%). Also, the isolates show the ability to form biofilm at a percentage of 68.7% with resistance to a high number of antibiotics. The multidrug-resistant and sensitive P. aeruginosa isolates scored high percentages (49.4% and 34.9%) whereas potentially pan drug-resistant and extensively drug-resistant isolates scored low percentages (2.4% and 13.3%). PCR results showed that integron I scored the highest percentage (100%) compared to integron 2 found in 3 (10%) isolates, and no intI3 gene was detected in any of the P. aeruginosa isolates. Conclusions. Overall, the findings of the present investigation indicate that integrons and biofilm development are recognized as significant factors contributing to antibiotic resistance in P. aeruginosa. The prevalence of class 1 integrons is shown to be significantly high in all bacterial isolates, with a complete occurrence rate of 100%. This high incidence of class 1 integrons is associated with the development of resistance to crucial antibiotics, including β-lactams, aminoglycosides, and cephalosporins.

Mycoplasma agalactiae Vaccines: Current Status, Hurdles, and Opportunities Due to Advances in Pathogenicity Studies.

Contagious agalactia (CA) is a serious multietiological disease whose classic etiological agent is Mycoplasma agalactiae and which causes high morbidity and mortality rates in infected herds. CA is classified as a notifiable disease by the World Organization for Animal Health due to its significant worldwide economic impact on livestock, primarily involving goat and sheep farms. The emergence of atypical symptoms and strains of M. agalactiae in wildlife ungulates reestablishes its highly plastic genome and is also of great epidemiological significance. Antimicrobial therapy is the main form of control, although several factors, such as intrinsic antibiotic resistance and the selection of resistant strains, must be considered. Available vaccines are few and mostly inefficient. The virulence and pathogenicity mechanisms of M. agalactiae mainly rely on surface molecules that have direct contact with the host. Because of this, they are essential for the development of vaccines. This review highlights the currently available vaccines and their limitations and the development of new vaccine possibilities, especially considering the challenge of antigenic variation and dynamic genome in this microorganism.

Genomic Features and Phylogenetic Analysis of Antimicrobial-Resistant Salmonella Mbandaka ST413 Strains.

In recent years, Salmonella enterica subsp. enterica serovar Mbandaka (S. Mbandaka) has been increasingly isolated from laying hens and shell eggs around the world. Moreover, this serovar has been identified as the causative agent of several salmonellosis outbreaks in humans. Surprisingly, little is known about the characteristics of this emerging serovar, and therefore, we investigated antimicrobial resistance, virulence, and prophage genes of six selected Brazilian strains of Salmonella Mbandaka using Whole Genome Sequencing (WGS). Multi-locus sequence typing revealed that the tested strains belong to Sequence Type 413 (ST413), which has been linked to recent multi-country salmonellosis outbreaks in Europe. A total of nine resistance genes were detected, and the most frequent ones were aac(6')-Iaa, sul1, qacE, blaOXA-129, tet(B), and aadA1. A point mutation in ParC at the 57th position (threonine → serine) associated with quinolone resistance was present in all investigated genomes. A 112,960 bp IncHI2A plasmid was mapped in 4/6 strains. This plasmid harboured tetracycline (tetACDR) and mercury (mer) resistance genes, genes contributing to conjugative transfer, and genes involved in plasmid maintenance. Most strains (four/six) carried Salmonella genomic island 1 (SGI1). All S. Mbandaka genomes carried seven pathogenicity islands (SPIs) involved in intracellular survival and virulence: SPIs 1-5, 9, and C63PI. The virulence genes csgC, fimY, tcfA, sscA, (two/six), and ssaS (one/six) were absent in some of the genomes; conversely, fimA, prgH, and mgtC were present in all of them. Five Salmonella bacteriophage sequences (with homology to Escherichia phage phiV10, Enterobacteria phage Fels-2, Enterobacteria phage HK542, Enterobacteria phage ST64T, Salmonella phage SW9) were identified, with protein counts between 31 and 54, genome lengths of 24.7 bp and 47.7 bp, and average GC content of 51.25%. In the phylogenetic analysis, the genomes of strains isolated from poultry in Brazil clustered into well-supported clades with a heterogeneous distribution, primarily associated with strains isolated from humans and food. The phylogenetic relationship of Brazilian S. Mbandaka suggests the presence of strains with high epidemiological significance and the potential to be linked to foodborne outbreaks. Overall, our results show that isolated strains of S. Mbandaka are multidrug-resistant and encode a rather conserved virulence machinery, which is an epidemiological hallmark of Salmonella strains that have successfully disseminated both regionally and globally.

The role of human rhinovirus in COPD exacerbations in Abu Dhabi: molecular epidemiology and clinical significance

ABSTRACT This study aimed to describe the molecular epidemiology and seasonality of human rhinovirus (HRV) in chronic obstructive pulmonary disease (COPD) and its association with COPD exacerbations in Abu Dhabi, the United Arab Emirates (UAE). Sputum specimens were collected for analysis from all COPD patients who visited a medical center from November 2021 to October 2022. The real-time quantitative polymerase chain reaction (qPCR) test was used to detect HRV. Of the 78 COPD patients included in the study, 58 (74%) patients presented with one or more exacerbation episodes. The incidence of COPD exacerbation peaked over the winter and substantially decreased during the summer. HRV positivity in patients during exacerbation (E1) was 11/58 (19%) and 15/58 (26%) two weeks after the exacerbation episode (E2). There was no significant difference in the HRV load in these patients. No statistically significant difference was observed in the detection of HRV during exacerbation compared to patients with stable COPD. This is the first study to assess the association between HRV detection by qPCR and COPD exacerbations in the UAE. The high sensitivity of the detection technology helped collect reliable epidemiologic data. Few studies have provided similar Middle East data. This study’s pattern of COPD exacerbations and HRV detection parallels that of temperate countries. This information can help with future, more extensive surveillance of respiratory viruses in the UAE and the Middle East and their association with COPD exacerbations.