Microbiology
Fatemeh Haj Ebrahim Tehrani; Mohammad Moradi; Narjes Ghorbani
Abstract
Background & Objective: Neonatal sepsis is one of the leading causes of mortality in neonatology wards. The aim of this study was to assess sepsis pathogens and antibacterial resistance patterns in a teaching hospital during seven years in Tehran, Iran. Methods: In this retrospective study, all neonates ...
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Background & Objective: Neonatal sepsis is one of the leading causes of mortality in neonatology wards. The aim of this study was to assess sepsis pathogens and antibacterial resistance patterns in a teaching hospital during seven years in Tehran, Iran. Methods: In this retrospective study, all neonates suspected to sepsis and fulfilling the sepsis criteria admitted to NICU ward of Mustafa Khomeini Hospital, Tehran, Iran during 2007 to 2014 were included. Demographic information, blood test results, blood culture results of neonates and antibiogram findings were extracted from their documents. Data was analyzed using SPSS 15. Results:Ninety neonates with positive culture test were included. Fifty-three were male (58.9%). Thirty neonates were delivered vaginally (33.3%) and 60 caesarean section (66.7%). Most bacterial growths in culture were Staphylococcus aureus and E. coli. The rates of resistance for antibiotics like ceftriaxone, cefotaxim and gentamycin were 5%, 30% and 15%, correspondingly. There were 15 cases (16.7%) with resistance to imipenem. Conclusion: Antibacterial resistance patterns vary in different parts of the world and even within a country, therefore assessing resistance patterns in a region is of great importance for proper management and treatment. Our findings might help physicians for proper selection of antibiotics for treatment of neonatal sepsis.
Ali Majidpour; Sara Fathi Zadeh; Mastaneh Afshar; Mohammad Rahbar; Mina Boustanshenas; Marjan Heidarzadeh; Leila Arbabi; Somayeh Soleymanzadeh Moghadam
Abstract
Background & Objective: Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA), represent serious nosocomial and community infections. Biofilm formation as an important virulence factor may be affected by sub-inhibitory levels of antibiotics. Few studies examined the effects of ...
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Background & Objective: Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA), represent serious nosocomial and community infections. Biofilm formation as an important virulence factor may be affected by sub-inhibitory levels of antibiotics. Few studies examined the effects of all therapeutic antimicrobial agents on clinical S.aureus. The current study aimed at observing the inducing and reducing effects of antibiotics, commonly used to treat staphylococcal infections on the production of staphylococcal biofilm. Methods: Four MRSA (1ATCC and 3 clinical) and 1 methicillin-susceptible Staphylococcus aureus (MSSA) strains with biofilm forming ability, evaluated by the Congo red agar (CRA) plate test, were employed. Biofilm formation was measured by crystal violet microtiter plate assay. Cefazolin, rifampicin, vancomycin, oxacillin, clindamycin, cotrimoxazole, minocycline, linezolid, azithromycin, and clarithromycin were added to wells ranging from 0.06to 128 µg/mL (1× to 1/1024 MIC dependent on the MIC value of each strain). Results: The current study showed that azithromycin and vancomycin had a significant inducing effect on biofilm formation. In contrast, linezolid, cefazolin, and clarithromycin, and in the second place, clindamycin and minocycline could inhibit the level of biofilm production in the sub-minimal inhibitory concentrations. Conclusion: The findings demonstrated that the biofilm formation as an important virulence factor may be affected by the subinhibitory levels of antibiotics.