Antibiotic utility and susceptibility changes of multidrug-resistant Escherichia coli and Klebsiella spp: 5-year experience in a tertiary healthcare centre.

OBJECTIVES: Multiple studies have identified cross-sectional relationships between antibiotic use and bacterial resistance. The aim of this study was to analyse the susceptibility of multidrug-resistant (MDR) and non-MDR (nMDR) isolates of Escherichia coli and Klebsiella spp to cephalosporins: ceftazidime (CTZ), ceftriaxone (CTX), cefepime (CEF) and fluoroquinolones: ciprofloxacin (CIP) and levofloxacin (LEV) in a tertiary healthcare centre from 2014 to 2018. In addition, we aimed to evaluate a correlation between the antibiotic utility and susceptibility of the selected enterobacteria. METHODS: Antibiotics consumption and antimicrobial resistance were monitored in a tertiary care university hospital from 2014 to 2018. Utilisation of antibiotics in the observed period was expressed as defined daily dose (DDD) per 100 bed/days (DBD). Bacterial susceptibility was reported as the percentage of susceptible results among all tested isolates from all patient samples. In further analysis, bacterial strains were considered as MDR or nMDR species. An MDR bacterial strain was defined as one with acquired non-susceptibility to at least one agent in three or more antimicrobial categories. RESULTS: Our results suggest that cephalosporins were the most used antibiotics, followed by fluoroquinolones, during the entire observed period 2014-2018. Our findings show that MDR isolates of E. coli had an increasing trend in susceptibility in relation to CTX (p=0.005), whereas a decreasing trend was observed for MDR isolates of E. coli susceptibility towards CIP and LEV (p<0.001). Klebsiella spp susceptibility for MDR isolates showed a decreasing trend in relation to CEF (p<0.001) and both fluoroquinolones (p<0.001). A significant negative association between CEF consumption and Klebsiella spp MDR isolates susceptibility was observed (p=0.045). CONCLUSION: Implementation of antimicrobial stewardship programmes with early detection and close monitoring of MDR bacterial strains of E. coli and Klebsiella spp may be a crucial step in reducing the menace of antimicrobial resistance, which is now a global problem.

Streptococcus pyogenes as the cause of vulvovaginitis and balanitis in children.

BACKGROUND: Streptococcus pyogenes (group A Streptococcus) is the etiological agent of perineal infection in children, consisting of perianal infection, vulvovaginitis and balanitis. If it is not properly diagnosed and treated, it can persist for many months and can cause severe complications. Furthermore, treatment with penicillin can be followed by failures and recurrences. METHODS: We report here the prevalence of S. pyogenes isolates in genital tract specimens from girls (n = 1692) with symptoms of vulvovaginitis and from boys (n = 52) with balanitis in the municipality of Nis, Southeast-Serbia (the Western Balkans) in a 10 year period, and the seasonal distribution, patient age and sensitivity to bacitracin and antimicrobial drugs used in the treatment of streptococcal infection. RESULTS: Streptococcal vulvovaginitis was diagnosed in 2.30% of examinees. Of those cases, 64.10% were detected from April to September, and it was most common (71.79%) in girls aged 3-7 years. Streptococcal balanitis was diagnosed in two instances: in a 4-year-old boy and in a 7-year-old boy. S. pyogenes strains resistant to bacitracin were identified in five girls. Two isolates with M phenotype and five isolates with cMLSB phenotype were identified. CONCLUSIONS: Streptococcal vulvovaginitis was diagnosed less often in the present study, but it was still far more common than streptococcal balanitis in childhood. Bacitracin resistance of S. pyogenes strains should be taken into account in routine microbiological identification, and the detection of S. pyogenes isolates resistant to erythromycin requires surveillance in the present geographical territory.

SUSCEPTIBILITY OF RESPIRATORY ISOLATES OF STREPTOCOCCUS PNEUMONIAE ISOLATED FROM CHILDREN HOSPITALIZED IN THE CLINICAL CENTER NIS.

INTRODUCTION: Streptococcus pneumoniae is one of the most common causes of respiratory infections. The aim was to study the susceptibility to antimicrobial agents of respiratory isolates ofStreptococcus pneumoniae obtained from hospitalized children. MATERIAL AND METHODS: A total of 190 respiratory pneumococcal isolates obtained from children aged from 0 to 14 years were isolated and identified by using standard microbiological methods. Susceptibility to oxacillin, erythromycin, clindamycin, tetracycline, cotrimoxazole, ofloxacin and rifampicin was tested by disc diffusion method. Minimal inhibitory concentrations for amoxicillin and ceftriaxone were determined by means of E test. The macrolide-resistant phenotype was detected by double disc diffusion test. RESULTS: All tested isolates were susceptible to amoxicillin and ceftriaxone. The minimal amoxicillin concentration inhibiting the growth of 50% of isolates and of 90% of isolates was 0.50 microg/ml and 1.0 microg/ml, respectively and the minimal ceftriaxone concentration inhibiting the growth of 50% of isolates and of 90% of isolates was 0.25 microg/ml and 0.50 microg/ml, respectively. Susceptibility to erythromycin and clindamycin was observed in 21.6% and 29.47% of isolates, respectively. The resistence to macrolides-M phenotype was detected in 10.07% of isolates and constitutive macrolide-lincosamide-streptogramin phenotype (constitutive MLS phenotype) was found in 89.93% of isolates. All tested isolates were susceptible to ofloxacin and rifampicin. CONCLUSION: Amoxicillin could be the therapy of choice in pediatric practice. The macrolides should not be recommended for the empirical therapy of pneumococcal respiratory tract infection in our local area.

In Vitro Evaluation of Nanoscale Hydroxyapatite-Based Bone Reconstructive Materials with Antimicrobial Properties.

In the field of oral implantology the loss of bone tissue prevents adequate patient care, and calls for the use of synthetic biomaterials with properties that resemble natural bone. Special attention is paid to the risk of infection after the implantation of these materials. Studies have suggested that some nanocontructs containing metal ions have antimicrobial properties. The aim of this study was to examine the antimicrobial and hemolytic activity of cobalt-substituted hydroxyapatite nanoparticles, compared to hydroxyapatite and hydroxyapatite/poly-lactide-co-glycolide. The antibacterial effects of these powders were tested against two pathogenic bacterial strains: Escherichia coi (ATCC 25922) and Staphylococcus aureus (ATCC 25923), using the disc diffusion method and the quantitative antimicrobial test in a liquid medium. The quantitative antimicrobial test showed that all of the tested biomaterials have some antibacterial properties. The effects of both tests were more prominent in case of S. aureus than in E coli. A higher percentage of cobalt in the crystal structure of cobalt-substituted hydroxyapatite nanoparticles led to an increased antimicrobial activity. All of the presented biomaterial samples were found to be non-hemolytic. Having in mind that the tested of cobalt-substituted hydroxyapatite (Ca/Co-HAp) material in given concentrations shows good hemocompatibility and antimicrobial effects, along with its previously studied biological properties, the conclusion can be reached that it is a potential candidate that could substitute calcium hydroxyapatite as the material of choice for use in bone tissue engineering and clinical practices in orthopedic, oral and maxillofacial surgery.

Microbiological aspects of vulvovaginitis in prepubertal girls.

UNLABELLED: This study aimed to establish the vaginal introitus microbial flora in girls with and without symptoms of vulvovaginitis, and to present the distribution of isolated microorganisms by age groups in girls with vulvovaginitis. We enrolled 500 girls with vulvovaginitis symptoms, aged 2-12 years, referred by their pediatricians for microbiological examination of the vaginal introitus swabs, and 30 age-matched asymptomatic girls. Similar microbial flora was isolated in both groups, but the symptomatic girls had significantly more common positive microbiological findings compared to controls (p < 0.001). In symptomatic girls, the following pathogenic bacteria were isolated: Streptococcus pyogenes (4.2%), Haemophilus influenzae (0.4%), and Staphylococcus aureus (5.8%). Bacteria of fecal origin were found in vaginal introitus swabs in 33.8% of cases, most commonly Proteus mirabilis (14.4%), Enterococcus faecalis (12.2%), and Escherichia coli (7.0%). The finding of fecal flora was more common compared to controls, reaching a statistical significance (p < 0.05), as well as in girls aged up to 6 years (p < 0.001). Candida species were found in 2.4% of girls with vulvovaginitis symptoms. CONCLUSION: The microbial ecosystem in girls with clinical signs of vulvovaginitis is complex and variable, and the presence of a microorganism does not necessarily imply that it is the cause of infection. The diagnosis of vulvovaginitis in prepubertal girls requires a complex and comprehensive approach, and microbiological findings should be interpreted in the context of clinical findings.

[High-density cervical Ureaplasma urealyticum colonization in pregnant women as a risk factor for premature rupture of membranes].

BACKGROUND/AIM: Ureaplasma urealyticum, a common commensal of the female lower genital tract, has been observed as an important opportunistic pathogen during pregnancy. The aims of this study were to determine the degree of cervical colonization with U. urealyticum in pregnant women with risk pregnancy and in pregnant women with normal term delivery and to evaluate the correlation between high-density cervical U. urealyticum colonization and premature rupture of membranes (PROM) as well. METHODS: This research was conducted on the samples comprizing 130 hospitalized pregnant women with threatening preterm delivery and premature rupture of membranes. The control group consisted of 39 pregnant women with term delivery without PROM. In addition to standard bacteriological examination and performing direct immunofluorescence test to detect Chlamydia trachomalis, cervical swabs were also examined for the presence of U. urealyticum and Mycoplasma hominis by commercially available Mycofast Evolution 2 test (International Microbio, France). RESULTS: The number of findings with isolated high-density U. urealyticum in the target group was 69 (53.08%), while in the control group was 14 (35.90%). Premature rupture of membranes (PROM) occurred in 43 (33.08%) examinees: 29 were pPROM, and 14 were PROM. The finding of U. urealyticum > or = 10(4) was determined in 25 (58.14%) pregnant women with rupture, 17 were pPROM, and 8 were PROM. There was statistically significant difference in the finding of high-density U. urealyticum between the pregnant women with PROM and the control group (chi2 = 4.06, p < 0.05). U. urealyticum was predominant bacterial species found in 62.79% of isolates in the PROM cases, while in 32.56% it was isolated alone. Among the 49 pregnant women with preterm delivery, pPROM occurred in 29 (59.18%) examinees, and in 70.83% of pregnant women with findings of high-density U. urealyticum pPROM was observed. CONCLUSION: Cervical colonization with U. urealyticum > or = 10(4) is more frequent in pregnant women with risk pregnancy than in pregnant women with normal term delivery. High-density cervical U. urealyticum colonization should be observed as a possible etiological factor for PROM.