BACKGROUND: Achromobacter spp. are opportunistic pathogens, mostly infecting immunocompromised patients and patients with cystic fibrosis (CF) and considered as difficult-to-treat pathogens due to both intrinsic resistance and the possibility of acquired antimicrobial resistance. Species identification remains challenging leading to imprecise descriptions of resistance in each taxon. Cefiderocol is a broad-spectrum siderophore cephalosporin increasingly used in the management of Achromobacter infections for which susceptibility data remain scarce. We aimed to describe the susceptibility to cefiderocol of a collection of Achromobacter strains encompassing different species and isolation sources from CF or non-CF (NCF) patients.
METHODS: We studied 230 Achromobacter strains (67 from CF, 163 from NCF patients) identified by nrdA gene-based analysis, with available susceptibility data for piperacillin-tazobactam, meropenem and trimethoprim-sulfamethoxazole. Minimal inhibitory concentrations (MICs) of cefiderocol were determined using the broth microdilution reference method according to EUCAST guidelines.
RESULTS: Strains belonged to 15 species. A. xylosoxidans represented the main species (71.3%). MICs ranged from ≤ 0.015 to 16 mg/L with MIC50/90 of ≤ 0.015/0.5 mg/L overall and 0.125/2 mg/L against 27 (11.7%) meropenem-non-susceptible strains. Cefiderocol MICs were not related to CF/NCF origin or species although A. xylosoxidans MICs were statistically lower than those of other species considered as a whole. Considering the EUCAST non-species related breakpoint (2 mg/L), 228 strains (99.1%) were susceptible to cefiderocol. The two cefiderocol-resistant strains (A. xylosoxidans from CF patients) represented 3.7% of meropenem-non-susceptible strains and 12.5% of MDR strains.
CONCLUSIONS: Cefiderocol exhibited excellent in vitro activity against a large collection of accurately identified Achromobacter strains, irrespective of species and origin.

UNASSIGNED: To investigate Corynebacterium striatum as a nosocomial pathogen infecting hard-to-heal peripheral wounds, such as skin wounds, soft tissue abscesses and osteomyelitis. As of 2023, the medical community were alerted against the risk of emerging systemic and central infections; on the other hand literature on peripheral cutaneous regions is still scarce.
UNASSIGNED: In this study, two groups of patients with similar lesions which were infected were compared: one group with the presence of the coryneform rod, the other without.
UNASSIGNED: In total, Corynebacterium striatum was cultured from 62 patients and 131 samples. Corynebacterium striatum infection correlated well with the presence of: foot ulcer; venous leg ulcer; altered ambulation and/or altered foot loading; peripheral vascular and arterial disease; hospitalisation; malignancy; spinal cord injury; and recent administration of antibiotics (p<0.05 for all associations). Patients with Corynebacterium striatum had a lower overall survival rate compared to patients in the non-Corynebacterium striatum group (28.6 versus 31.6 months, respectively; p=0.0285). Multivariate analysis revealed that Corynebacterium striatum infection was an independent factor for poor prognosis (p<0.0001).
UNASSIGNED: In view of the findings of our study, Corynebacterium striatum appears to be an important opportunistic pathogen infecting peripheral tissues and complicating wound healing. Given its numerous and worrying virulence factors (such as multidrug resistance and biofilm production), particular attention should be given to this pathogen by professional wound care providers in nosocomial and outpatient environments.

BACKGROUND: Polymicrobial infections are complex infections associated with worse outcomes compared to monomicrobial infections. We need simple, fast, and cost-effective animal models to assess their still poorly known pathogenesis.
METHODS: We developed a Drosophila melanogaster polymicrobial infection model for opportunistic pathogens and assessed its capacity to discriminate the effects of bacterial mixtures taken from cases of human polymicrobial infections by Aeromonas strains. A systemic infection was obtained by needle pricking the dorsal thorax of the flies, and the fly survival was monitored over time. Different lineages of the flies were infected by a single strain or paired strains (strain ratio 1:1).
RESULTS: Individual strains killed more than 80% of the flies in 20 h. The course of infection could be altered with a microbial mix. The model could distinguish between the diverse effects (synergistic, antagonistic, and no difference) that resulted in a milder, more severe, or similar infection, depending on the paired strain considered. We then investigated the determinants of the effects. The effects were maintained in deficient fly lineages for the main signaling pathways (Toll deficient and IMD deficient), which suggests an active microbe/microbe/host interaction.
CONCLUSIONS: These results indicate that the D. melanogaster systemic infection model is consistent with the study of polymicrobial infection.

Pregnancy outcomes and women\'s health are directly affected by vaginal microbiota. This microbiota consists of a dynamic ecosystem of various microbes in different ratios, which in healthy conditions protect the vaginal epithelium from infections. However, cases of vaginal infection are regularly diagnosed in women of reproductive age, contributing to more severe outcomes. Therefore, our main goal was to determine the prevalence of bacterial vaginosis (BV), aerobic vaginitis (AV), and vulvovaginal candidiasis (VVC) among Ecuadorian pregnant and non-pregnant women. A cross-sectional study was conducted among 217 women between 13 and 40 years old seeking primary healthcare in Carlos Andrade Marin Hospital (HCAM), Gynecological-Obstetric Hospital Isidro Ayora (HGOIA) and Center for Teaching Health Cipriana Dueñas during October 2018 to February 2019. The classical characterization of the vaginal microbiota was performed through microscopy by the Nugent criteria to evaluate the presence of BV, healthy and intermediate microbiota, by the criteria of Donders to determine the presence of AV and by the Marot-Leblond criteria to diagnose VVC. DNA extraction from vaginal samples and Polymerase Chain Reaction (PCR) analysis was performed to characterize the presence of Gardnerella spp., Mobiluncus mulieris, Escherichia coli, Enterococcus spp., and Lactobacillus spp. Finally, quantification of the lactobacilli was performed by quantitative real-time PCR (qPCR) for samples from women with normal vaginal microbiota and women with AV. Our results showed 52% of women with healthy microbiota, 7% with intermediate microbiota, and 41% with vaginal dysbiosis, comprising 27% with AV, 8% with BV and 4% with VVC and 2% with co-infections or co-dysbiosis. Additionally, a higher amount of lactobacilli were found in pregnant women when compared to non-pregnant women, while AV cases were characterized by a significant drop of Lactobacillus spp., more precisely, between 1E3 and 1E5 colony forming units (CFU)/ml. Finally, women with normal vaginal microbiota showed an average load of lactobacilli between 1E6 and 1E7 CFU/ml. This pilot study showed no statistically significant differences between pregnant and non-pregnant women, pointing to the possibility to use lactobacilli quantification for the prevention of future vaginal infections.

The present study explored the association between multiple antibiotic resistance (MAR) index and virulence index to determine what percent of environmental antibiotic-resistant (eARB) bacteria could pose threat as potential pathogen. 16srRNA-based sequencing of 113 non-duplicate isolates identified majority of them to be gram negative belonging to Enterobacter, Pseudomonas, Aeromonas, Proteus, Acinetobacter, and Klebsiella. Statistical comparison of MAR indices of the abovementioned genera indicated differences in the median values among the groups (p < 0.001). Pair-wise multiple comparison by Dunn\'s method indicated significant difference in MAR indices (p < 0.05), based on which multiple antibiotic resistance phenotype could be ranked in the order Pseudomonas > Klebsiella = Acinetobacter > Proteus > Aeromonas > Enterobacter. Association between MAR index and virulence index revealed that 25% of isolates in the population under study posed high threat to human/animal or both; out of which 75% isolates belonged to genus Pseudomonas. Based on observations of comparative analysis of the six gram-negative genera, it could be concluded that Pseudomonas isolates from environment pose significantly high threat as potential pathogens while Enterobacter isolates posed no threat.