Epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) is continually changing. Frequency of genotypes typical for community-associated MRSA (CA-MRSA) is increasing in hospitals, as well ...as resistance to antimicrobial agents. Moreover, different clones predominate in different geographic regions, and temporal shifts occur in the predominant clonal type. The aim of this study was to estimate the prevalence of MRSA, CA-MRSA and PVL-positive MRSA isolates from patients hospitalised in the Military Medical Academy (MMA) and from outpatients, and to perform genotyping of PVL-positive MRSA isolates. MRSA isolates were obtained by standard microbiological techniques. PVL-positive MRSA were detected by single PCR. Determination of SCCmec types in MRSA isolates was done using multiplex PCR and genotyping of PVL-positive MRSA by PFGE, MLST and spa typing. The prevalence of MRSA among S. aureus isolates from different clinical specimens was 43.4%. In outpatients the prevalence of MRSA was 3.2%. SCCmec types specific for CA-MRSA were found in 26% of MRSA isolates from hospitalised patients. In groups, hospitalised patients and outpatients, the prevalence of PVL-positive MRSA isolates was 4%, and all of them harboured SCCmec type V genetic element. PFGE revealed minor differences between four groups of PVL-positive MRSA isolates, but all of them belonged to ST152, and all except one were of the t355 spa type. High prevalence of MRSA and CA-MRSA in MMA, especially the presence of PVL-positive CA-MRSA, represent a serious health threat for patients. Genotype t355/ST152/SCCmec V is the dominant MRSA clone among PVL-positive CA-MRSA.
Twenty-seven colistin-resistant, carbapenemase-producing
isolates were identified from hospitals in Serbia. All isolates were
positive; ST101, ST888, ST437, ST336, and ST307 were
positive; and ST340 ...was
positive. ST307 had an insertion, and ST336 had a premature stop codon in the
gene. Amino acid substitutions were detected in PmrAB of isolates ST101, ST888, ST336, and ST307. The
and
were not detected. An increase in
,
, and
gene transcription was detected for all sequence types.
Bacterial biofilms play an important role in the pathogenesis of chronic upper respiratory tract infections. In addition to conventional antimicrobial therapy, N-acetyl-L-cysteine (NAC) and propolis ...are dietary supplements that are often recommended as supportive therapy for upper respiratory tract infections. However, no data on the beneficial effect of their combination against bacterial biofilms can be found in the scientific literature. Therefore, the aim of our study was to investigate the in vitro effect of N-acetyl-L-cysteine (NAC) and dry propolis extract in fixed combinations (NAC/dry propolis extract fixed combination) on biofilm formation by bacterial species isolated from patients with chronic rhinosinusitis, chronic otitis media, and chronic adenoiditis. The prospective study included 48 adults with chronic rhinosinusitis, 29 adults with chronic otitis media, and 33 children with chronic adenoiditis. Bacteria were isolated from tissue samples obtained intraoperatively and identified using the MALDI-TOF Vitek MS System. The antimicrobial activity, synergism, and antibiofilm effect of NAC/dry propolis extract fixed combination were studied in vitro. A total of 116 different strains were isolated from the tissue samples, with staphylococci being the most frequently isolated in all patients (57.8%). MICs of the NAC/dry propolis extract fixed combination ranged from 1.25/0.125 to 20/2 mg NAC/mg propolis. A synergistic effect (FICI ≤ 0.5) was observed in 51.7% of strains. The majority of isolates from patients with chronic otitis media were moderate biofilm producers and in chronic adenoiditis they were weak biofilm producers, while the same number of isolates in patients with chronic rhinosinusitis were weak and moderate biofilm producers. Subinhibitory concentrations of the NAC/propolis combination ranging from 0.625–0.156 mg/mL to 10–2.5 mg/mL of NAC combined with 0.062–0.016 mg/mL to 1–0.25 mg/mL of propolis inhibited biofilm formation in all bacterial strains. Suprainhibitory concentrations ranging from 2.5–10 mg/mL to 40–160 mg/mL of NAC in combination with 0.25–1 mg/mL to 4–16 mg/mL of propolis completely eradicated the biofilm. In conclusion, the fixed combination of NAC and dry propolis extract has a synergistic effect on all stages of biofilm formation and eradication of the formed biofilm in bacteria isolated from upper respiratory tract infections.
Multidrug-resistance of methicillin-resistant Staphylococcus aureus (MRSA) is a serious therapeutical problem. Chalcones belong to a group of naturally occurring flavonoids, usually found in various ...plant species, and have potent antibacterial, antiviral and antifungal activities. The goal of this study was to evaluate the antibacterial effect of three newly-synthesized chalcones against clinical isolates of MRSA, and their synergism with β-lactam and non-β-lactam antibiotics.
Antimicrobial activity of the three newly-synthesized chalcones was tested against 19 clinical isolates of MRSA and a laboratory control strain of MRSA (ATCC 43300). The synergism with β-lactams: cefotaxime (CFX), ceftriaxone (CTX), and non-β-lactam antibiotics: ciprofloxacin (CIP), gentamicin (GEN) and trimethoprim/sulphamethoxazole (TMP-SMX) was investigated by checkerboard method.
All evaluated compounds showed significant anti-MRSA activity with MIC values from 25-200 μg/ml. Observed synergism with antibiotics demonstrated that chalcones significantly enhanced the efficacy of CIP, GEN and TMP-SMX.
Our study demonstrated that three newly-synthesized chalcones exhibited significant anti-MRSA effect and synergism with non-β-lactam antibiotics. The most effective compound was 1,3-Bis-(2-hydroxy-phenyl)-propenone. Our results provide useful information for future research of possible application of chalcones in combination with conventional anti-MRSA therapy as promising new antimicrobial agents.
Background
Chronic rhinosinusitis (CRS) is one of the most common health disorders in humans and has a major impact on health-related quality of life (HRQoL). Of the many factors contributing to the ...etiology of CRS, less is known about the correlation between CRS and bacterial biofilms and their impact on HRQoL.
Objective
The aim of this prospective study was to investigate the relationship between biofilm-producing bacteria and patients' objective findings and HRQoL.
Methods
Forty-eight patients with CRSwNP were enrolled in a 12-month prospective study. The Lund-Mackay (LM) CT and endoscopic Lund-Kennedy (LK) scores were obtained before endoscopic sinus surgery (ESS), and patients completed the HRQoL instruments: the 22-item Sinonasal Outcome Test (SNOT−22), the 36-item Short Questionnaire (SF−36), and the visual analog scale (VAS). A sinus culture was obtained at ESS, bacteria were isolated, and in vitro quantification of the biofilm was performed. The LK score and HRQoL were determined postoperatively at months 1, 3, 6, and 12.
Results
The most common bacterial isolates in patients with CRSwNP were Staphylococcus aureus (28%), coagulase-negative staphylococci (52%), and Pseudomonas aeruginosa (8%). Preoperatively, the highest LM and LK scores were found in patients with strong biofilm producers. Postoperative LK scores were significantly reduced in all patients. Postoperative VAS scores were significantly reduced from month 1 to month 12 postoperatively. Patients with strong biofilm producers had significantly worse nasal blockage, secretion, headache, facial pressure and pain, and loss of smell preoperatively, compared to patients with low biofilm producers. The most significant reduction in preoperative scores SNOT−22 and SF−36 (excluding physical functioning) was seen in patients with S. aureus and P. aeruginosa.
Conclusions
Patients with strong biofilm producers had higher LK and LM scores preoperatively, and greater improvement in LK and HRQoL scores postoperatively. Microbiologic surveillance of all CRS patients is recommended.
Hands of healthcare workers play essential role in the spreading of antimicrobial-resistant microorganisms in and out of the healthcare settings. Less is known about the role of laboratory workers ...(LWs). The aim of our study was to evaluate the presence of biofilm-forming staphylococci on the surface of jewelry rings of LWs and their antimicrobial susceptibility pattern.A total of 79 LWs from eight different microbiology laboratories that process and analyze specimens from the tertiary care hospitals in Belgrade, Serbia participated in the study. The study was reviewed and approved by the institutional review boards at hospitals. Samples were taken after hand washing. Bacteria on LWs wedding rings were detected with the rolling method, and further analyzed in order to determine the number of colony forming unit (CFU) per ring, species of bacteria and their antimicrobial susceptibility pattern, methicillin resistance and biofilm-producing capacity in vitro.Staphylococci were recovered from 60.8% of wedding rings. All strains produced biofilm (25% weak, 56.2% moderate and 18.8% large amount), with significant difference between species (P < 0.001). Staphylococcus aureus and Staphylococcus epidermidis formed the largest amount of biofilm and had the largest number of CFU per ring. Staphylococci were most commonly resistant to penicillin (66.7%), tetracycline (50.0%), and erythromycin (45.8%); 41.7% of isolates was multidrug resistant and mecA gene was detected in five strains. All strains were susceptible to linezolid, vancomycin, teicoplanin and tigecycline.Staphylococci colonize LWs wedding rings, form biofilm on it, have multidrug resistant phenotype and/or carry mecA gene, representing a significant reservoir for the spreading of microorganisms and resistance. As far as we know, our study is the first that address this topic in laboratory workers.
The types of carbapenemases and clonal relatedness among community isolates of carbapenemase-producing
in Belgrade, Serbia, were determined.
During the period 2016-2020,
community isolates were ...screened for carbapenemases, and carbapenemase production was confirmed by multiplex PCR. Clonality was determined based on genetic profiles obtained by enterobacterial repetitive intergenic consensus PCR.
Carbapenemase genes were detected in 114 of 4800 isolates (2.4%). The most frequent gene was
. Most isolates (70.5%) were grouped in ten clusters. Cluster 11 contained 16.4% of all
-positive isolates, and all
-positive isolates were grouped in one cluster.
Laboratory-based detection and surveillance are highly recommended in order to control the spread of resistance in community settings.
As the only non-European Union (EU) country, Serbia participated in a second point prevalence survey of healthcare-associated infections (HAIs) and antimicrobial use (AMU) organized by the European ...Centre for Disease Prevention and Control (ECDC) in the EU countries. Here, we aimed to estimate the prevalence of HAI and AMU in patients who had recently undergone a surgery and to compare risk profile, HAI rates, and AMU among surgical patients and non-surgical patients.
A national PPS was performed in 65 Serbian acute-care hospitals, in November 2017. In this paper, the data of 61 hospitals for adult acute-care were analyzed. To ensure the comparability of study design we used the Serbian translation of ECDC case definitions and ECDC PPS protocol. The trained infection control staff, led by a hospital coordinator, reviewed medical records to identify HAI active at the time of the survey and AMU. Only inpatients admitted to the ward before 8 a.m. on the day if the survey were included.
A total of 12,478 patients from 61 hospitals for adult acute-care were eligible for inclusion in this study. Significantly higher proportions of surgical patients were female, belonged to the 60-to-79 age group, and were less severely ill. Also, extrinsic factors (invasive devices, hospitalization at the ICU, and prior antibiotics therapy) were more frequent in surgical patients. Prevalence of HAIs was higher among surgical patients (261/3626; 7.2%) than among non-surgical patients (258/8852; 2.9%) (p < 0.0001). The highest prevalence of all HAIs was noted in patients who had kidney transplantation (4/11; 36.4%), while SSIs were the most prevalent among patients who had peripheral vascular bypass surgery (3/15; 20.0%). Non-surgical patients received treatment for community-acquired infections in significantly higher proportion (2664/8852; 64.3) (p < 0.001). Surgical prophylaxis for more than 1 day was applied in 71.4% of surgical patients.
We have provided an insight into the burden of HAIs and AMU among Serbia acute-care hospitals, and highlighted several priority areas and targets for quality improvement.
Antimicrobial resistance (AMR) is considered one of the most prevalent global health issues in both veterinarian and human medicine. This complex problem requires a "One Health" approach with the ...cooperation of all healthcare sectors, as well as agriculture, finance, and consumers. We conducted a survey with the objective to assess the knowledge and attitudes of farm animal veterinarians toward AMR and antimicrobial use in the Republic of Serbia with a small focus on mastitis therapy. A total of 110 respondents completed the questionnaire, which represents a response rate of 27.3%. The majority of our respondents (
= 102, 92.7%) completely agreed that AMR currently represents severe concern in the health sector. Unfortunately, less than one-third (
= 34, 30.9%) of the respondents had only heard about antimicrobial stewardship. Participants showed a positive attitude toward prudent antimicrobial use and were open to solutions to the AMR crisis. We noticed a certain gap between farm veterinarians' desire to improve and perform better in daily practice, while at the same time feeling like they did not have enough guidance, help, and resources.
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