Between January 1997 and December 1999, bloodstream isolates from 15,439 patients infected with Staphylococcus aureus and 6350 patients infected with coagulase-negative Staphylococcus species (CoNS) were referred by SENTRY-participating hospitals in the United States, Canada, Latin America, Europe, and the Western Pacific region. S. aureus was found to be the most prevalent cause of bloodstream infection, skin and soft-tissue infection, and pneumonia in almost all geographic areas. A notable increase in methicillin (oxacillin) resistance among community-onset and hospital-acquired S. aureus strains was observed in the US centers. The prevalence of methicillin (oxacillin)-resistant S. aureus varied greatly by region, site of infection, and whether the infection was nosocomial or community onset. Rates of methicillin resistance were extremely high among S. aureus isolates from centers in Hong Kong and Japan. Uniformly high levels of methicillin resistance were observed among CoNS isolates. Given the increasing multidrug resistance among staphylococci and the possible emergence of vancomycin-resistant strains, global strategies are needed to control emergence and spread of multiply resistant staphylococci.
Two bla OXA-48 -like-positive isolates (Klebsiella pneumoniae and Enterobacter cloacae) were recovered in Argentina in 2008 as part of a large-scale survey focused on multidrug resistance in Enterobacteriaceae. In both cases, sequencing identified -lactamase OXA-163, differing from OXA-48 by a single amino substitution and a 4-amino-acid deletion. OXA-163 hydrolyzed penicillins, ceftazidime, and cefotaxime, whereas OXA-48 did not. However, OXA-163 had a much lower ability to hydrolyze carbapenems than OXA-48, therefore barely being considered a carbapenemase. In both isolates, the bla OXA-163 gene was located on plasmids that differed in structure and size. However, a detailed genetic analysis revealed a similar genetic context in those isolates, with the bla OXA-163 gene being bracketed by novel transposase genes, making this genetic environment different from that reported for the bla OXA-48 gene. This study identified the first class D -lactamase compromising both extended-spectrum cephalosporin and carbapenem activities.Class D -lactamases or oxacillinases are widely distributed among clinically relevant Gram-negative species (31). A high degree of diversity is observed at the biochemical and genetic levels among these enzymes exhibiting a narrow or broad spectrum of hydrolysis toward -lactams (31). Genes encoding oxacillinases are usually embedded as gene cassettes into class 1 integrons, but other potentially mobile genetic vehicles have also been described, including insertion sequences (ISs) (31). Among class D -lactamases, some enzymes confer the ability to hydrolyze carbapenems and have mostly been identified in Acinetobacter spp. (32) but rarely in Enterobacteriaceae (33). The carbapenem-hydrolyzing class D -lactamase (CHDL) OXA-48 was initially identified in Turkey, first in Klebsiella pneumoniae and then in other enterobacterial species (1,5,6,15,23,29). OXA-48 exhibits a hydrolysis profile that includes penicillins and carbapenems and that spares cephalosporins (29). Lately, the bla OXA-48 gene has been identified in different countries, such as Lebanon, Tunisia, Israel, Belgium, and France and recently in Senegal and Morocco (3,[9][10][11]14,19,[20][21][22]34). Several isolates producing OXA-48 have been involved as a source of nosocomial outbreaks (5, 11). The bla OXA-48 gene has often been identified on a 70-kb plasmid featured by the replication protein RepP (6). The bla gene is usually identified in association with two IS1999 insertion sequences, forming the composite transposon Tn1999 (2). Here we report an OXA-48-related CHDL that possesses very peculiar hydrolytic properties and whose gene is associated with novel genetic structures. MATERIALS AND METHODSBacterial strains. Identification of K. pneumoniae (isolate Kp6299) and Enterobacter cloacae 2185 (isolate Enc2185) was performed by using the API 20E system (bioMérieux, Marcy l'Étoile, France). Escherichia coli TOP10 was used as the host strain for cloning, and E. coli J53 (resistant to azide) was used as the host for conjugation ...
Twenty-five plasmid-specified antimicrobial resistance determinants common to gram-negative bacilli from nosocomial infection were investigated from 31 Stenotrophomonas maltophilia isolates. Twenty-four clones were identified by pulsed-field gel electrophoresis, and in three clones that exhibited an increased trimethoprimsulfamethoxazole MIC, the sul1 determinant was found. These results support not only the higher spread of class 1 integrons compared to other mechanisms but also the potential limitation of using trimethoprimsulfamethoxazole for therapy of severe S. maltophilia infections.
Objective: To determine the prevalence of Gardnerella vaginalis, anaerobic bacteria and Mycoplasma hominis in vaginal specimens of women with and without bacterial vaginosis (BV) as well as to determine the sensitivity and specificity of the direct sialidase assay of vaginal fluid as a rapid test for diagnosing this syndrome. Methods: Vaginal cultures were obtained from 109 nonpregnant women (mean age 33 ± 7.1 years), 47 of them with clinical signs of BV (BV+) and 62 of them without BV (BV- ). In addition, we determined the vaginal sialidase activity in both groups, which may serve as a feature of this syndrome. Results: Anaerobic bacteria were isolated in 91% and 18% of the BV+and BV- groups, respectively (p < 0.001). Peptostreptococcus spp., Prevotella bivia and Porphyromonas spp. were strongly associated with BV. P. bivia and Prevotella spp. represented 44% of all the anaerobes isolated in the BV+ group. All the isolated P. bivia strains presented sialidase activity. G. vaginalis and M. hominis were isolated in 76% and 42% of the BV+ and 1% and 0% of the BV- women, respectively (p < 0.001). Mobiluncus morphotypeswere observed in 34% of the BV+and 0% of BV- women. Sensitivity, specificity, positive predictive value and negative predictive value of sialidase activity were 81%, 94%, 90% and 86%, respectively. Conclusions: Our data demonstrate a strong association between G. vaginalis, M. hominis, and P. bivia and BV. Sialidase activity and Gram stain of vaginal fluid represent accurate methods for diagnosing BV.
Saksenaea erythrospora is a species of the order Mucorales recently described and reported as a cause of human mucormycosis. We report a case of S. erythrospora in a man involved in a serious sailing accident causing deep skin and soft tissue contamination with soil and water. Direct microscopic examination of the clinical sample with Giemsa stains showed hyaline and nonseptate hyphae belonging to the order Mucorales. Fungal identification was performed by culture of biopsy material on SDA, and identification of species by floating an agar block containing the fungus in a nutritionally deficient medium consisting of sterile distilled water supplemented with 0.05 % yeast extract; and by sequencing the ITS region of the rDNA. This is the first report to our knowledge of infection with S. erythrospora in Argentina, confirming the presence of this fungus in this country.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.