Nontyphoidal Salmonella serotypes are diverse in their host range and vary in their pathogenic capability. They can cause huge economic losses due to human and animal infections worldwide. Biofilms are essential to the survival of microorganisms in their natural habitat, either the environment or the human body. This study aimed to investigate the ability of nontyphoidal Salmonella strains isolated from contaminated food of animal origin to produce biofilm in different incubation conditions such as nutrient media and incubation temperatures. Bacterial strains analyzed in this study were recovered from the food samples of animal origin in the Public Institution Veterinary Institute of the Republic of Srpska "Dr. Vaso Butozan" between 2017 and 2018 year. Biofilm production was determined by crystal violet assay in a microtiter plate in Trypticase-Soy (TSB) and Brainheart Infusion (BHI) broths during overnight incubation at 4 ℃, 25 ℃, and 37 ℃. A total of 30 Salmonella isolates were detected in 730 samples (4.1%), mainly from chicken meat (27 isolates). S. Infantis (14 isolates) and S. Enteritidis (12 isolates) were the two most common serotypes. As expected, none of the isolates were strong biofilm producers at all three incubation temperatures in both broths. Although the refrigeration temperature was the most unfavorable for biofilm creation, there were no significant statistical differences between tested incubation temperatures in BHI broth (p ≥ 0.05). In TSB broth, a significant statistical difference was found between isolates incubated at all three temperatures (p < 0.001, p < 0.001, p < 0.001). The lowest temperature was the least suitable for the formation of biofilm, whereas ambient temperature was the most favorable for biofilm production. When we compared the biofilm production in TSB and BHI broths, we observed that TSB was the better broth for efficient biofilm production only at 25 ℃ and 37 ℃ (p <0.001, p=0.049).  The temperature and medium composition are important for biofilm production. Salmonella's ability to form biofilms at ambient and refrigeration temperatures is significant in the poultry, catering, and household industries, allowing for long-term bacterial persistence.

The human cytomegalovirus (CMV) is a ubiquitous pathogen and an important factor contributing to morbidity and mortality in patients with hematologic malignancies. Serological demonstration of prior exposure to CMV is essential in this population. A number of factors including gender and age may influence CMV seropositivity in patients with B-cell neoplasms as they do in healthy individuals. Herein, we have investigated CMV serostatus in non-transplanted patients with lymphoid B-cell malignancies. Significance of gender, age, and the underlying type of lymphoid cancer in connection to seroprevalence were examined. Blood samples of seventy adult patients were screened for CMV IgG and IgM antibodies by means of an enzyme linked immunosorbent assay (ELISA). Group comparisons were performed using pertinent statistical tests and data were analyzed using IBM SPSS 20.0 statistical software. The overall CMV seroprevalence was 88.6%. The acquisition of CMV was greater in females (p=0.266) and older patients (p=0.07) than male and younger individuals. The largest seroprevalence was evidenced in patients >60 years (95.2%). Age was ostensibly co-incremental with the degree of CMV exposure (p=0.054). The extent of CMV seropositivity and the particular type of B-cell malignancy were not related (p=0.339). CMV seroprevalence in patients with lymphoid B-cell neoplasms is higher in females and older individuals, without predilection for a particular type of underlying neoplasm.

Carbapenem-resistant Acinetobacter baumannii (CRAB) is endemic in Serbia. CRAB initially emerged around the 2000s, and since then, carbapenemases have played a crucial role in its appearance. Oxacillinases (OXAs) are the most prevalent carbapenemases detected in CRAB isolates collected from patients admitted to Serbian hospitals. Among acquired OXA enzymes, OXA-23 and OXA-24 are the most commonly found. NDM-1-producing CRAB was also detected. The predominant OXA-23 and OXA-24 producers are associated with multilocus sequence typing (MLST) Pasteur scheme sequence type (ST) 2 and ST492 clonal strains of the international clone (IC) II. Isolated CRABs are typically multidrug-resistant (MDR) strains which complicates the treatment options. This review aims to go through the molecular epidemiology of CRAB clinical isolates in Serbia, as one of the most important aspects for implementing infection control measures and adjusted antimicrobial treatment strategies in hospital settings that could confine clonal CRAB spread.

Streptococcus pneumoniae is the most common causative agent of community-acquired pneumonia, which may progress to invasive pneumococcal infections when the pathogen penetrates the pleura or bloodstream, leading to sepsis. This study aimed to determine the distribution of serotypes among patients with pneumonia and analyze the invasive serotypes’ re-sistance to antibiotics. A retrospective research study was conducted at the Department of Microbiological Diagnostics at the Institute for Pulmonary Diseases of Vojvodina in Sremska Kamenica from January 2015 to December 2020. Isolates were obtained from the blood and pleural fluid of pneumonia patients. Antimicrobial susceptibility was determined using the disc diffu-sion method and gradient tests. Serotype determination was performed by the National Reference Laboratory for Strepto-cocci (NRL) using the Quellung reaction and capsular polysaccharide antisera. During the study period, 66 isolates were collected from an equal number of patients. Of all the patients, 46 (69.7%) were male, and 20 (30.30%) were female. Among these, 33 (50%) were adults, and 33 (50%) were elderly. Pleural fluid yielded 40 (60.6%) isolates, while blood samples provided 26 (39.4%) isolates. There were 21 (31.8%) isolates from the summer period and 45 (68.1%) from the winter period. The isolates exhibited high resistance to co-trimoxazole (39.4%), penicillin (33.3%), erythromycin (28.78%), and clindamycin (25.8%), while they remained fully sensitive to vancomycin, teicoplanin, and linezolid. A total of 11 distinct serotypes were detected: 1, 3, 4, 7F, 9N, 10A, 14, 15A, 19A, 19F, and 23B. Invasive serotypes displayed substantial resistance to co-trimoxazole, penicillin, erythromycin, clindamycin, levofloxa-cin, and moxifloxacin. The highest resistance was observed in serotypes 19F, 15A, and 14..

In the post-COVID-19 era, there has been a notable surge in the development of mRNA vaccines. These vaccines are not only targeting various pathogens beyond SARS-CoV-2 but also hold promise in treating cancer and genetic disorders. These type of vaccines are revolutionizing vaccinology through their inherent possibility for rapid pandemic response, high efficacy, minimal side effects, and cost-effectiveness. Achieving these benefits hinges on seamlessly integrating mRNA production steps, from plasmid DNA (pDNA) design and antigen cloning, in vitro transcription to lipid nanoparticle formulation. A critical initial step in mRNA vaccine production is pDNA cloning vector design. The vector should be carefully constructed considering a copy number of plasmid, vector backbone with a promoter, the origin of replication, multiple cloning sites, polyadenylation signal, and markers for selection. However, despite careful design, challenges like poly-A tail deletion may arise, prompting the exploration of stable large-size and low-copy vectors, as well as linear and bacteriophage vectors. Additionally, for large-scale production and regulatory compliance, vector systems must be scalable and well-documented. This overview aims to elaborate upon the intricacies in pDNA cloning vector design. The focus is on achieving accurate insert sequence, especially those encoding the complex antigens and gene expression, highlighting the critical role of pDNA design in ensuring vaccine effectiveness. Although commercial vectors and automated synthesis facilitate gene construction, challenges still exist. This emphasizes that a multifaceted approach, combining molecular biology techniques, computational tools, and collaboration with experts in microbiology, molecular biology, and vaccine development, is required for successful mRNA vaccine development.