Sustained Transmission of Neisseria gonorrhoeae Strains with High-Level Azithromycin Resistance (MIC ≥ 256 μg/mL) in Argentina, 2018 to 2022.

Azithromycin combined with ceftriaxone is the recommended dual therapy for uncomplicated gonorrhea in many countries. Nevertheless, the increasing prevalence of azithromycin resistance compromises the effectiveness of this treatment strategy. From 2018 to 2022, we collected 13 gonococcal isolates with high-level azithromycin resistance (MIC ≥ 256 μg/mL) across Argentina.

Genomic epidemiology of isolated from bloodstream infections in South America during 2019 supports regional surveillance.

remains one of the leading causes of infections worldwide and a common cause of bacteraemia. However, studies documenting the epidemiology of in South America using genomics are scarce. We hereby report on the largest genomic epidemiology study to date of both methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) in South America, conducted by the StaphNET-SA network.

New sequence type of an Enterobacter cloacae complex strain with the potential to become a high-risk clone.

Objectives: Enterobacter cloacae complex (ECC) has awakened interest recently because of its increasing resistance to carbapenems codified by several genes all over the globe. Even though there are some sequence types (STs) which represent high-risk clones, there is substantial clonal diversity in the ECC. This work aimed to perform whole-genome sequencing (WGS), genomic analysis, and phylogenetic studies of a Klebsiella pneumoniae carbapenemase (KPC) -producing multidrug-resistant (MDR) ECC isolate from Argentina.

Testing of Susceptibility of Neisseria gonorrhoeae to Azithromycin: Comparison of Disk Diffusion and Reference Agar Dilution Methods.

Azithromycin in combination with ceftriaxone is recommended as the first-line treatment for uncomplicated gonorrhea in many countries. Therefore, monitoring of azithromycin susceptibility of isolates is essential. In 2019, the Clinical and Laboratory Standards Institute (CLSI) listed the MIC breakpoint for a susceptible-only category to azithromycin, but breakpoints for disk diffusion are not yet available.

Mucoidy, quorum sensing, mismatch repair and antibiotic resistance in Pseudomonas aeruginosa from cystic fibrosis chronic airways infections.

Survival of Pseudomonas aeruginosa in cystic fibrosis (CF) chronic infections is based on a genetic adaptation process consisting of mutations in specific genes, which can produce advantageous phenotypic switches and ensure its persistence in the lung. Among these, mutations inactivating the regulators MucA (alginate biosynthesis), LasR (quorum sensing) and MexZ (multidrug-efflux pump MexXY) are the most frequently observed, with those inactivating the DNA mismatch repair system (MRS) being also highly prevalent in P. aeruginosa CF isolates, leading to hypermutator phenotypes that could contribute to this adaptive mutagenesis by virtue of an increased mutation rate.

Pharmacodynamic assessment of Amoxicillin-Sulbactam against Acinetobacter baumannii: searching the optimal dose and infusion time through a human ex-vivo model.

Amoxicillin-sulbactam (AMX-SUL) is an aminopenicillin/ss-lactamase inhibitor combination currently available in 29 countries and may be a suitable option for treating infections caused by Acinetobacter spp. Thus, we sought to search the optimal dosing strategy for this formulation through an ex vivo pharmacodynamic human model against Acinetobacter baumanniii. Four volunteers were randomized to receive alternatively a single dose AMX-SUL infused both either over 30 min or 3h at the following ratios (g/g): 1/0.

Emergence of high level azithromycin-resistant Neisseria gonorrhoeae strain isolated in Argentina.

One Neisseria gonorrhoeae strains highly resistant to azithromycin AzHLR (MIC >2048 mg/L) was isolated in Argentina in 2001 and it has been characterized by N. gonorrhoeae multiantigen sequence typing (NG-MAST) as ST696, suggesting a different event to other isolates in Europe. Neither, mtrR mutations or presence of mef gene were detected.

Vaginal microflora associated with bacterial vaginosis in nonpregnant women: reliability of sialidase detection.

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-).

Comparison of several methods to determine methicillin-resistance in Staphylococcus aureus with focus on borderline strains.

We compared the performance of several phenotypic tests to detect methicillin-resistant Staphylococcus aureus, with special focus on borderline strains. The reliability of the agar screen oxacillin and BBL Crystal tests was asserted for all methicillin-susceptible (n = 25), -resistant (n = 29) and borderline beta-lactamase-hyperproducer (n = 10) strains. Whereas these tests failed to detect 4 of 5 rare borderline strains containing few cells with high-level methicillin resistance (i.

Broth disk elution method for anaerobic bacteria: a collaborative study to assess its reliability for clinical purposes.

A collaborative study involving seven laboratories was undertaken to evaluate the reproducibility and the reliability of the broth disk elution test against anaerobic bacteria by comparing with the reference agar dilution method. A two breakpoint broth test was also evaluated. Assays were performed using the same testing conditions (i.