Clinical and molecular characteristics of OXA-72-producing Acinetobacter baumannii ST636 outbreak at a neonatal intensive care unit in Serbia.

AIM: To describe an Acinetobacter baumannii outbreak among preterm neonates in a neonatal intensive care unit (NICU) in Serbia. METHODS: A case-control study was conducted in the NICU at the Institute of Neonatology, Belgrade, Serbia. The case definition of A. baumannii bloodstream infection (BSI) was blood culture confirmation of systemic infection. Isolation, identification and susceptibility testing were performed using conventional methods. Molecular characterization of isolates included resistance gene detection, pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing. Outcomes and clinical and demographic data were obtained from patients' medical records. An infection prevention team was formed and infection control interventions were implemented. FINDINGS: During the outbreak period (May-July 2018), there were 13 cases of A. baumannii BSI among 82 hospitalized neonates. All A. baumannii strains were carbapenem resistant and susceptible to colistin. Molecular characterization of the isolates revealed that they harboured blaOXA66 and blaOXA72 beta-lactamases and belonged to sequence type 636, while the PFGE pattern indicated clonal spread. Lower gestational age, lower Apgar score, vaginal delivery and mechanical ventilation were risk factors for A. baumannii infection. Four patients died, eight patients were treated successfully with colistin, and one patient with sepsis and meningitis on dual ampicillin-sulbactam and colistin therapy recovered with sequelae. The outbreak was eventually controlled by reinforcement of the infection control measures based on a multi-tiered interventional approach. CONCLUSION: This is the first description of an outbreak of BSI among preterm neonates caused by A. baumannii blaOXA66/blaOXA72/ST636 in Serbia.

Trends in macrolide resistance of respiratory tract pathogens in the paediatric population in Serbia from 2004 to 2009.

We report the first study of macrolide resistance in respiratory tract pathogens in a Serbian paediatric population. It included 5293 Streptococcus pneumoniae, 4297 Streptococcus pyogenes, 2568 Moraxella catarrhalis and 1998 Haemophilus influenzae isolates derived from the respiratory tract and 110 invasive isolates from children aged up to 18 years during 2004-2009. Over the 6-year period, a significant increase (P < 0·01) in macrolide resistance was found in both S. pneumoniae and S. pyogenes that reached 45% and 19%, respectively, in 2009. In the same period, consumption of macrolides increased continually from 2·46 to 5·8 defined daily dose/1000 inhabitants per day. The increase in macrolide resistance in S. pyogenes correlated with consumption of total macrolide and long-acting macrolides (r = 0·879, P = 0·05 and r = 0·922, P = 0·026, respectively). A similar trend was observed in pneumoccoci, although it did not reach statistical significance. The growing problem of macrolide resistance in pneumococci and S. pyogenes in Serbia requires further vigilant surveillance.

Typing of macrolide resistant group A streptococci by random amplified polymorphic DNA analysis.

OBJECTIVE: Several studies of group A streptococci (GAS) have revealed that a small number of dominant resistant clones might be responsible for the spread of Streptococcus (S.) pyogenes resistance to macrolides. We aimed to determine the genetic diversity of macrolide resistant group A streptococci (MRGAS), isolated from patients with pharyngitis in Serbia. MATERIALS AND METHODS: The clonal relationships among 76 MRGAS isolates collected during 2008 were studied using two molecular typing methods: emm typing and random amplified polymorphic DNA (RAPD) analysis. Isolates that share the same emm type and RAPD pattern were considered to belong to the same clone. RESULTS: Out of 7 distinct emm types identified, the 3 most frequently occurring overall were emm12, emm75 and emm77 (> 90% of isolates). Although as many as 26 different RAPD patterns were found among the isolates studied, two clones with emm12 and emm77 accounted 32 out of 76 (42%) isolates. CONCLUSIONS: The results indicate a polyclonal spread of erythromycin-resistant Streptococcus pyogenes in our country. Furthermore, predominance of two clones, particularly among emm12 and emm77 strains indicates that erythromycin-resistant GAS of the same clonal origin are widely distributed in Serbia.

Distribution of emm types among group A streptococcal isolates from Serbia.

This is the first study concerning the molecular epidemiology of group A streptococcus in Serbia and includes 145 isolates from patients with various infections during the period 2001-2007. The emm types, superantigen profile and susceptibility pattern were determined. Among 31 emm types identified, the most prevalent were emm 6, emm 12, emm 1, and emm 58. All isolates showed uniform antimicrobial susceptibility to all tested antibiotics, with the exception of tetracycline and erythromycin (41% and 0.7% resistant strains, respectively). Significant heterogeneity of emm types was found, with a high frequency of emm 6 and emm 58, as well as a considerable prevalence of tetracycline resistance, and a low level of macrolide resistance.

Biotypes of group A streptococci from patients with pharyngitis and soft tissue infections.

This study determined the biotypes of group A streptococci (GAS) isolated from 66 pharyngeal and 62 skin and soft-tissue infections. Among all GAS isolates tested, the most common biotypes were 1 and 3, irrespective of the isolation source and the severity of clinical symptoms. However, compared with the pharyngeal group, a more heterogeneous distribution of biotypes was observed among the cutaneous group of isolates, including seven isolates that were non-typeable but had an identical biotype pattern, suggesting that they may represent a new biotype.

[Colonization of cental venous catheter in the Intensive Care Units at the Institute of Cardiovascular Disease "Dedinje"--one year study].

OBJECTIVES: The application of Central Venous Catheters (CVC) is associated with increased risk of microbial colonization and infection. The aim of present study was to assess the frequency of pathogens colonizing CVC and to determine their susceptibility pattern to various antimicrobial agents. MATERIALS AND METHODS: A total of 253 samples of CVC from intensive care units (ICU) patients were received for culture during 2003. All microorganisms were identified by standard microbiological methods and the susceptibility to antimicrobial agents was determined according to NCCLS recommendations. RESULTS: A total of 184 (72.7%) cultures were positive and 223 pathogens were isolated. Coagulase negative staphylococci (CNS) were the dominant isolates (24.7%), followed by Enterobacter spp. (12.1%), Pseudomonas spp. (11.7%), Enterococcus spp. (9.9%), Klebsiella spp. (8.6%), Candida spp. (7.6%), Acinetobacter spp. (7.6%), other Gram negative nonfermentative bacilli (5.8%), Serratia spp. (4.5%), Staphylococcus aureus (2.6%), Proteus mirabilis (2.2%), E. coli (1.8%) and Citrobacter spp. (0.9%). Meropenem (84.5%) and vancomycin (100%) remain the most effective antimicrobial agents against Gram negative and Gram positive bacteria, respectively. CONCLUSION: Gram negative bacilli and CNS are the commonest microorganisms colonizing CVC from ICU patients. The increasing resistance of the bacteria to antimicrobial agents is the major problem in spite of restricted policy of using antimicrobial agents in ICU.

[Role of environmental factors in the development of insulin-dependent diabetes mellitus (IDDM) in Venezuelan children]. / Papel de los factores ambientales en el desarrollo de la Diabetes Mellitus Insulino Dependiente (DMID) en niños venezolanos.

In view of the controversy surrounding the role of environmental factors, such as the presence of bovine albumin in milk, or viral infections, in the etiology of IDDM, a study was undertaken to determine the relationship between these events and the subsequent risk of developing IDDM. On 40 venezuelan diabetic children (< 18 y) and forty, age, sex and race-matched controls were studied at the same time. Parents of children completed a questionnaire on the infant's feeding habits, its environment and family history. The X2 method and the Fischer's exact test were used to analyze the results. We found that 20% of the controls, and 10% of IDDM (NS), were never breast-fed. In 95% of controls vs 65% of IDDM (p < 0.001), cow's milk was given exclusively from birth, or combined with breast-feeding, 65% of IDDM and 60% of controls (NS) were breast-fed (alone or combined with milk substitutes) for more than three months. These results do not support the hypothesis that early exposure to breast milk substitutes increases the risk of IDDM in venezuelan children. The study revealed, however, that a family history of diabetes mellitus was present in 55% of IDDM vs 30% of controls (p < 0.05) and mumps infection before the onset of diabetes was recorded in 42.5% of IDDM in comparison with 12.5% of controls (p = 0.005). Other viral infections (rubella, chicken pox) had no statistical significance. The latter results suggest an association between a family history of diabetes mellitus and viral infections with the development of IDDM among this group of children.