Department of Microbiology, Kaunas University of Medicine, A. Mickeviciaus 9, 44307 Kaunas, Lithuania.
The aim of this study was to identify the phage groups of Staphylococcus aureus strains, their prevalence, and resistance of different phage groups to antibiotics.
MATERIALS AND METHODS.
A total of 294 Staphylococcus aureus strains in Kaunas hospitals were obtained; they were phage typed and their resistance to antibiotics was determined. We used the method of routine dilution to test 17 antibiotics against the isolates. Susceptibility of Staphylococcus aureus to studied antibiotics was estimated on the basis of National Committee for Clinical Laboratory Standards according to minimal inhibition concentration of each antibiotic. Staphylococcus aureus strains were phage typed by the international diagnostic set of Staphylococci bacteriophages (Moscow, Russia).
After evaluating the resistance of obtained Staphylococcus aureus strains to oxacillin/methicillin, it was determined that 5.8% of Staphylococcus aureus were resistant to methicillin. Almost all strains (93.75%) of methicillin-resistant Staphylococcus aureus were susceptible to the fusidic acid, 18.75% - to ciprofloxacin; 31.25% of methicillin-resistant Staphylococcus aureus strains were susceptible to gentamicin, 37.5% - to doxycycline, and just 6.25% - to erythromycin. The strains of methicillin-susceptible Staphylococcus aureus are susceptible to many studied antibiotics. The strains of methicillin-susceptible Staphylococcus aureus are most resistant to penicillin - 83.1% and to erythromycin - 29.9%. Phage typing revealed that 20.9% of methicillin-susceptible Staphylococcus aureus and 56.2% of methicillin-resistant Staphylococcus aureus were nontypable.
Using the international set of bacteriophages, 79.1% of methicillin-susceptible Staphylococcus aureus and 43.8% of methicillin-resistant Staphylococcus aureus strains were phage typed. Among the strains of methicillin-resistant Staphylococcus aureus, phagotype 77 of phagogroup III was the most common and among the strains of methicillin-susceptible Staphylococcus aureus - phagotype 3C of phagogroup II.
PMID: 16687905 [PubMed - as supplied by publisher]A study on Staphylococcus aureus strains submitted to a reference laboratory.
Mehndiratta PL, Vidhani S, Mathur MD.
National Staphylococcal Phage Typing Center, Department of Microbiology, Maulana Azad Medical College, New Delhi, India.
BACKGROUND & OBJECTIVES:
Staphylococcus aureus is regarded as one of the most devastating human pathogens. Recently there have been reports of increasing incidence of S. aureus strains resistant to methicillin (MRSA). A surveillance study was undertaken to record the occurrence of MRSA and to study the prevalence of various phage groups in India.
A total of 7574 strains of S. aureus received during 1992-98 at the National Staphylococcal Phage Typing Centre, New Delhi were tested for methicillin resistance and susceptibility to phages of the International basic set. The occurrence of various phage groups between MRSA and MSSA (methicillin sensitive S. aureus) was compared. Results were analyzed according to the geographical origin and source of isolation of the strains.
The dominant phage group from different parts of the country was phage group III. Prevalence of phage group III among the MRSA and MSSA isolates was 62.32 and 33.95 per cent respectively. The highest isolation of phage group III strains was from nasal carriers (45.94%), phage group II strains from skin (8.74%), phage group I strains from blood (19.44%) and nontypable strains from the environment (80.68%). An increase in the occurrence of MRSA has been noticed from 9.83 per cent in 1992 to 45.44 per cent in 1998.
INTERPRETATION & CONCLUSION:
S. aureus strains of phage group III are prevalent in India. The increase in occurrence of MRSA indicates an alarming spread of these organisms. A constant monitoring is important to take appropriate and timely measures to control their spread.PMID: 11873403
[PubMed - indexed for MEDLINE]