Limosilactobacillus caccae sp. nov., a new bacterial species isolated from the human gut microbiota

ABSTRACT Strain Marseille-P3519T isolated from the fecal flora of a 25-year-old healthy French woman was a Gram-positive anaerobic bacterium, non-motile and non-spore forming. The 16S rRNA gene sequence of Marseille-P3519 showed 97.73% of sequence similarity with Limosilactobacillus reuteri DSM 20016, the closest species, phylogenetically. Furthermore, the average nucleotide identity of strain Marseille-3519 with its closest related species was 75.8% that was very below the recommended threshold (>95–96%). Its genome had 2 237 367 bp with 45.42 mol% of G + C content. Major fatty acids were C16:0 (50.8%), C18:1n9 (18.0%), C18:2n6 (9.8%) and C19:1n9 (8.9%). It was catalase negative and fermented glycerol, glucose, fructose, D-maltose, lactose and mannose. These findings support that strain Marseille-P3519 ( = CSURP3519 = CECT 30110) is a new member of the genus Limosilactobacillus for which the name Limosilactobacillus caccae sp. nov., is proposed.

Organ Specific Differences in Alteration of Aquaporin Expression in Rats Treated with Sennoside A, Senna Anthraquinones and Rhubarb Anthraquinones

Senna and rhubarb are often used as routine laxatives, but there are differences in mechanism of action and potential side effects. Here, we studied metabolites of senna anthraquinones (SAQ), rhubarb anthraquinones (RAQ) and their chemical marker, sennoside A (SA), in a rat diarrhea model. In in vitro biotransformation experiments, SAQ, RAQ and SA were incubated with rat fecal flora solution and the metabolites produced were analyzed using HPLC. In in vivo studies, the same compounds were investigated for purgation induction, with measurement of histopathology and Aqps gene expression in six organs. The results indicated that SAQ and RAQ had similar principal constituents but could be degraded into different metabolites. A similar profile of Aqps down-regulation for all compounds was seen in the colon, suggesting a similar mechanism of action for purgation. However, in the kidneys and livers of the diarrhea-rats, down-regulation of Aqps was found in the RAQ-rats whereas up-regulation of Aqps was seen in the SAQ-rats. Furthermore, the RAQ-rats showed lower Aqp2 protein expression in the kidneys, whilst the SA-rats and SAQ-rats had higher Aqp2 protein expression in the kidneys. This may have implications for side effects of SAQ or RAQ in patients with chronic kidney or liver diseases.

Evaluating the prevalence of plasmid- mediated quinolone resistant and ESBL- production in Uropathogenic Escherichia coli and the commensal gut microbiota in pregnant women: A comparative analysis

Background: ß-lactam and fluoroquinolone antibiotics are frequently prescribed for urinary tract infections (UTIs). This study aimed to determine the prevalence of plasmid-mediated quinolone resistance (PMQR) and extended spectrum β-lactamases (ESBLs) in E. coli from UTIs in comparison with the E. coli isolates from gut microbiota (fecal flora).Methods: A total of 54 E. coli urine isolates and 54 E. coli fecal flora isolates were collected from pregnant women (same host) from April to September 2018. Antimicrobial susceptibility testing was determined by disk diffusion method. ESBLs were detected via double-disk test (DDST). ESBL and PMQR-encoding genes were identified, using PCR.Results: The highest resistance rate was found against nalidixic acid (42 isolates in urinary and 41 in fecal flora isolates) and the lowest resistance rate belonged to levofloxacin (23 isolates) and ofloxacin (25 isolates) in urinary and fecal flora isolates. The most prevalent PMQR genes were qnrS (29 isolates in urinary and 34 in fecal flora isolates) followed by qnrB, aac (6′)- Ib-cr and qnrA in urinary and fecal flora isolates. There was a significant association between qnrS gene and blaTEM in urinary and fecal flora isolates.Conclusions: Resistance to quinolones antibiotics was highest among fecal flora isolates, especially qnrS among other determinants of the qnr gene. In addition, it seems that high load of PMQR genes in commensal flora has a potential to spread to pathogenic organisms.

Prevalence of Antibiotic Resistance in Escherichia coli from the Fecal Flora of Humans in a Rural Area of Songkhla Province

Objective: To determine the prevalence of antibiotic resistance in fecal Escherichia coli (E. coli ) isolated from humans in a rural area of Songkhla province.Meterial and Methods: E. coli strains were isolated from the stool cultures of 75 healthy volunteers in a rural area. Resistance rates for 8 antibiotics were determined.Results: The resistance rates for amoxicillin, doxycyclin, cotrimoxazole, gentamicin and cefazolin were 53.3, 51.3, 24.0, 5.3 and 3.3%, respectively. No resistance to norfloxacin, ceftriaxone, and imipenem were detected.Conclusion: The most prevalent resistant strains were found against amoxicillin. The prevalence of drug resistance in all multidrug resistant isolates were resistant to amoxicillin and doxycycline. No strains were resistant to all antibiotics in all antimicrobial categories as all the strains were found to be sensitive to ceftriazone, norfloxacin and imipenem.

2583. Short-term Impact of Antimicrobial Exposure on Fecal Carriage of Resistant Microorganisms

Background The relationship between antimicrobial use and subsequent resistance is complicated; this study assesses the short-term impact of antimicrobial use on fecal carriage of resistant microorganisms. This is a sub-study of an ongoing trial comparing 7 vs. 14 days of antimicrobial treatment for male urinary tract infection. This analysis quantifies the effect of 1–2 weeks of systemic antimicrobial use on the fecal flora within 1 week of completing therapy. Methods The parent study has enrolled 216 subjects, with 178 enrolled in the optional resistance sub-study. Subjects received either ciprofloxacin or trimethoprim/sulfamethoxazole (SXT), randomized to 7 vs. 14 days therapy. Subjects provided 2 stool specimens, 1 during treatment and 1 a week after completing study medication. Samples were plated on media for Gram-positive and negative growth, including T-7 plates with ciprofloxacin and SXT added to select for resistant organisms. Resistance to 22 antimicrobials was assessed, with resistance reported by: number of isolates with any antimicrobial resistance, total number of resistant drugs/isolate, and number of isolates with multi-drug resistance (resistance to 3 or more different antimicrobial classes). Results Overall, 143 (80%) subjects provided 2 stool samples, with 104 (73%) having growth from at least 1 of the samples. Fifty-one of 143 (36%) had microbial growth from both samples. From these 51 paired samples, there were 255 total strains isolated (117 from the first sample, 138 from the second), with some yielding multiple organisms (range, 1–5). From sample 1, 110/117 (94%) isolates had any antimicrobial resistance, vs. 131/138 (95%) from sample 2 (P = .79). Mean number of resistant drugs/isolate was 7.4 in sample 1 and 5.8 in sample 2 (P = .009). Multi-drug resistance was seen in 102/117 (87%) isolates from sample 1 vs. 85/138 (62%) isolates in sample 2 (P < .001). Conclusion The fecal flora of patients on antimicrobial therapy for UTI has a significant increase in resistant microorganisms compared with samples obtained shortly after antimicrobial completion. This may reflect repopulation of the fecal flora with less-resistant strains after the selection pressure of therapy has been removed. After unblinding, we will assess if differences in resistance are affected by therapy duration. Disclosures All authors: No reported disclosures.