Given that the Shigella species that were studied showed a high level of resistance to the most frequently used antibiotics, surveillance activities should be implemented in order to detect and control the appearance of new resistant strains. Applying epidemiological typing techniques can provide more precise information about the distribution and evolution of resistant strains of circulating microorganisms.

Salmonella Infantis has been the second most common serovar in Argentina in the last two years, being isolated mostly from paediatric hospitalised patients. In order to determine the clonal relationship among Salmonella Infantis strains, we examined 15 isolates from paediatric patient faeces in Argentina (12 geographically related and 3 geographically non-related) by using antimicrobial susceptibility, plasmid profiling, repetitive extragenic palindromic (REP) PCR, enterobacterial repetitive intergenic consensus (ERIC) PCR, and low-frequency restriction analysis of chromosomal DNA by pulsed field gel electrophoresis (PFGE). Four Spanish strains were included as controls of clonal diversity in molecular techniques. Antibiotype and plasmid profile was not useful as epidemiological tools. PFGE and REP-PCR were able to discriminate between Argentinean and Spanish isolates of Salmonella Infantis allowing to detect genetically related strains in three different cities. This finding indicates that a possible spread of a clone of this serovar in the North-eastern Region of Argentina has taken place in 1998.

We studied the bacteriology ofmaxillary sinus aspirates obtain ed from patients diagnosed with chronic sinusitis. We recovered 659 strains from 510 aspirates; of these, 572 (86.8 %) were aerobes and 87 (13.2 %) were anaerobes. Aerobes only were recovered from 310 of the 510 specimens (60.8%) and anaerobes only from 31 (6.1 %). Among the 572 aerobic bacteria, the most prevalent organisms were Streptococcus viridans (158 strains [27.6%]), Streptococcus pneumoniae (67 [11 .7 %}), Corynebacterium species (66 [11 .5 %]), Staphylococcus aureus (54 [9.4%]), Moraxella catarrhalis (38 [6.6%]), Hemophilus parainfluenzae (33 [5.8%]), and group C beta-hemolytic streptococci (26 [4.5%]). Amon g the 87 recovered anaerobes were species ofPep tostreptococcus (32 strains [36.8 %]), Prevotella (22 [25.3 %]), Actinomyces (13 [14.9 %]), Propionibacterium (11 [12.6%]), Fusobacterium (8 [9 .2 %]), and Veillonella (l [1.1%]). Beta-lactamase p roduction was detected in 115 ofthe 572 aerobic strains (20.1 %) and in 10 of the 87 anaerobic strains (11.5 %). Wefound that the prevalence and type of organisms we identified in chronic sinusitis did not differ substantiallyfrom those reported in pr evious studies. Our study is one ofthe more extensive reports on the type and prevalence ofpathogens in chronic sinusitis that has been publ ished to date.

No abstract

No abstract