Proteus penneri

Fecal carriage of extended-spectrum beta-lactamase-producing Enterobacterales in healthy Spanish schoolchildren

Background

Extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-E) are a serious threat among emerging antibiotic resistant bacteria. Particularly, the number of cases of ESBL-E infections reported in children has been increasing in recent years, and approved antibiotic treatments for this age group are limited. However, information regarding the prevalence of colonization in European children, risk factors associated with colonization, and the characteristics of the colonizing strains is scarce. The aims of this study were to determine the prevalence of ESBL-E colonization in fecal samples of apparently healthy schoolchildren, to identify lifestyle routines associated with colonization, and to characterize clonal relationships and mechanisms of resistance in ESBL-E isolates.

Methods

A cohort of 887 healthy children (3-13  years old) from seven primary and secondary schools in the Madrid metropolitan area was recruited between April-June 2018, and sociodemographic information and daily habits were collected. Fecal samples were screened for ESBL-E carriage in selective medium. ESBL-E isolates were further characterized by assessing molecular epidemiology (PFGE and MLST), ESBL gene carriage, and antibiotic resistance profile. This information was analyzed in conjunction with the metadata of the participants in order to identify external factors associated with ESBL-E carriage.

Results

Twenty four ESBL-E, all but one Escherichia coli, were detected in 23 children (prevalence: 2.6%; 95% CI: 1.6-3.6%). Of these, seven contained the bla_CTX-M-14 allele, five the bla_CTX-M-15, five the bla_SHV-12, three the bla_CTX-M-27, three the bla_CTX-M-32, and one the bla_CTX-M-9. Significant clonal diversity was observed among the isolates that grouped into 22 distinct clusters (at <85% similarity of PFGE profile). ESBL-producing E. coli isolates belonged to 12 different STs, with ST10 (25%) and ST131 (17%) being the most frequent. Apart from ß-lactams, resistance to trimethoprim/sulfamethoxazole (46%), ciprofloxacin (33%), levofloxacin (33%), tobramycin (21%), and gentamicin (8%) were the most frequently detected.

Conclusion

The prevalence of ESBL-E in the studied cohort of children was lower than the average colonization rate previously detected in Europe for both children and adults. E. coli was the main ESBL-producing species detected and CTX-M were the most frequently identified ESBLs. High ST diversity suggests polyclonal dissemination. Compared to other STs, ST131 isolates were associated with resistance to various antimicrobials.

Infection of Diabetes Foot Caused by Carbapenem-Resistant Proteus penneri Mediated by a Novel Plasmid Containing blaNDM

Objective

A strain of Proteus penneri with carbapenem resistance was found in a patient with a diabetic foot infection. We studied drug resistance, genome, and homology of P. penneri to support clinical prevention and treatment of infection caused by carbapenem-resistant P. penneri (CR-PPE).

Methods

The strains were obtained through bacterial culture from purulence. VITEK 2 compact (GN13) and Kirby-Bauer (K-B) disk diffusion methods were used for antimicrobial susceptibility testing. Ceftriaxone, amikacin, gentamicin, ampicillin, aztreonam, ceftazidime, ciprofloxacin, levofloxacin, cefepime, trimethoprim-sulfamethoxazole, tobramycin, cefotetan, piperacillin-tazobactam, ampicillin-sulbactam, ertapenem, piperacillin, meropenem, cefuroxime, cefazolin, cefoperazone/sulbactam, cefoxitin, and imipenem were used for antimicrobial susceptibility testing. After bacterial genome extraction, sequencing, and sequence assembly, whole-genome sequencing (WGS) was performed to explore the CR-PPE genotype.

Results

CR-PPE was resistant to two carbapenems (imipenem and ertapenem), ceftriaxone, and cefazolin, and was sensitive to aztreonam, piperacillin-tazobactam, and cefotetan. WGS results depict that the resistant phenotype of CR-PPE is consistent with the genotype, without common virulence genes of Enterobacteriaceae bacteria detected (virulence factor database). The carbapenem resistance gene blaNMD-1 is contained in a new plasmid, pWF127-NDM. The transposon Tn125 in pWF127-NDM carrying blaNMD-1 has almost the same structure as Tn125 in the reference plasmid pHFK418-NDM (Accession: MH491967). In addition, through phylogenetic analysis, CR-PPE depicts the closest evolutionary relationship with GCF 024129515.1, which was found in Gallus gallus in the Czech Republic in 2019 (downloaded from National Center for Biotechnology Information database). According to the evolutionary tree, CR-PPE has high homology with the two P. penneri strains found in China.

Conclusion

CR-PPE exhibits strong drug resistance owing to the presence of multiple resistance genes. CR-PPE infection should receive more attention, especially in patients with underlying diseases, such as diabetes and weak immunity.

The unique structure of bacterial polysaccharides - Immunochemical studies on the O-antigen of Proteus penneri 4034-85 clinical strain classified into a new O83 Proteus serogroup

The serological classification scheme of the opportunistic Proteus bacilli includes a number of Proteus penneri strains. The tested P. penneri 4034-85 strain turned out to be serologically distinguished in ELISA and Western blotting. The O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of this strain and studied by sugar and methylation analyses and dephosphorylation along with ¹H and ¹³C NMR spectroscopy, including 2D ¹H,¹H COSY, TOCSY, ROESY, ¹H,¹³C HSQC, HMBC, and HSQC-TOCSY experiments, The O-polysaccharide was found to have a linear repeating unit containing glycerol 1-phosphate and two residues each of Gal and GlcNAc. The following O-polysaccharide structure was established, which, to our knowledge, is unique among known bacterial polysaccharide structures.

Seasonal Microbial Conditions of Locally Made Yoghurt (Shalom) Marketed in Some Regions of Cameroon

The microbial conditions of locally made yoghurt (shalom) marketed in three areas of Cameroon were evaluated during the dry and rainy seasons alongside three commercial brands. A total of ninety-six samples were collected and the microbial conditions were based on total aerobic bacteria (TEB), coliforms, yeasts, and moulds counts as well as the identification of coliforms and yeasts using identification kits. Generally, there was a significant increase (p ≤ 0.05) in total aerobic and coliform counts (especially samples from Bamenda), but a decrease in yeast and mould counts of the same samples during the rainy season when compared to those obtained during the dry season. These counts were mostly greater than the recommended standards. Twenty-one Enterobacteriaceae species belonging to 15 genera were identified from 72 bacterial isolates previously considered as all coliforms. Pantoea sp. (27.77%) was highly represented, found in 41% (dry season) and 50% (rainy season) of samples. In addition, sixteen yeast species belonging to 8 genera were equally identified from 55 yeast isolates and Candida sp. (76.36%) was the most represented. This result suggests that unhygienic practices during production, ignorance, warmer weather, duration of selling, and inadequate refrigeration are the principal causes of higher levels of contamination and unsafe yoghurts.