Nosocomial Outbreak of Carbapenemase-Producing Proteus mirabilis With Two Novel Salmonella Genomic Island 1 Variants Carrying Different blaNDM–1 Gene Copies in China

NDM-1-producing multidrug-resistant Proteus mirabilis brings formidable clinical challenges. We report a nosocomial outbreak of carbapenem-resistant P. mirabilis in China. Six P. mirabilis strains collected in the same ward showed close phylogenetic relatedness, indicating clonal expansion. Illumina and MinION sequencing revealed that three isolates harbored a novel Salmonella genomic island 1 carrying a blaNDM–1 gene (SGI1-1NDM), while three other isolates showed elevated carbapenem resistance and carried a similar SGI1 but with two blaNDM–1 gene copies (SGI1-2NDM). Four new single nucleotide mutations were present in the genomes of the two-blaNDM–1-harboring isolates, indicating later emergence of the SGI1-2NDM structure. Passage experiments indicated that both SGI variants were stably persistent in this clone without blaNDM–1 copy number changes. This study characterizes two novel blaNDM–1-harboring SGI1 variants in P. mirabilis and provides a new insight into resistance gene copy number variation in bacteria.

The QseEF Two-Component System-GlmY Small RNA Regulatory Pathway Controls Swarming in Uropathogenic Proteus mirabilis

Bacterial sensing of environmental signals through the two-component system (TCS) plays a key role in modulating virulence. In the search for the host hormone-sensing TCS, we identified a conserved qseEGF locus following glmY, a small RNA (sRNA) gene in uropathogenic Proteus mirabilis. Genes of glmY-qseE-qseG-qseF constitute an operon, and QseF binding sites were found in the glmY promoter region. Deletion of glmY or qseF resulted in reduced swarming motility and swarming-related phenotypes relative to the wild-type and the respective complemented strains. The qseF mutant had decreased glmYqseEGF promoter activity. Both glmY and qseF mutants exhibited decreased flhDC promoter activity and mRNA level, while increased rcsB mRNA level was observed in both mutants. Prediction by TargetRNA2 revealed cheA as the target of GlmY. Then, construction of the translational fusions containing various lengths of cheA 5′UTR for reporter assay and site-directed mutagenesis were performed to investigate the cheA-GlmY interaction in cheA activation. Notably, loss of glmY reduced the cheA mRNA level, and urea could inhibit swarming in a QseF-dependent manner. Altogether, this is the first report elucidating the underlying mechanisms for modulation of swarming motility by a QseEF-regulated sRNA GlmY, involving expression of cheA, rcsB and flhDC in uropathogenic P. mirabilis.

Human and Companion Animal Proteus mirabilis Sharing

Proteus mirabilis is an important pathogen that is associated with urinary tract infections. This study aims to determine the colonization and sharing of P. mirabilis between healthy companion animals and humans that are living together and to evaluate the clonal relatedness of the fecal and clinical stains. Eighteen households (24 humans, 18 dogs, 8 cats) with at least one human–animal pair were studied. Fecal samples were plated onto MacConkey and Hektoen agar and P. mirabilis PFGE analysis (NotI; Dice/UPGMA; 1.5% tolerance) was conducted for the households with multiple positive participants. Antimicrobial-resistance was tested according to CLSI. The fecal P. mirabilis pulse-types were compared with uropathogenic clinical strains (n = 183). Forty-nine P. mirabilis were isolated from eight households. The percentage of colonization in the dogs (44.4%, n = 8/18) was significantly higher (p = 0.0329) than in the humans (12.5%, n = 3/24). Three households had multiple colonized participants. One human–dog pair shared related P. mirabilis strains, which clustered with a clinical strain of animal origin (82.5%). One fecal P. mirabilis strain, from a dog, clustered with two human community-acquired clinical strains (80.9%, 88.9%). To our knowledge, this is the first report of dogs and humans living in close contact and sharing related P. mirabilis strains. The high frequency of colonization in the dogs underlines their possible role as P. mirabilis reservoirs for humans and other dogs.

Microwave assisted extraction, phytochemical and antimicrobial evaluation of ethyl acetate extracts of stem bark of Ficus exasperata (Vahl)

Stem bark of Ficus exasperata was extracted using ethyl acetate by microwave-assisted solvent extraction. Phytochemical screening and antimicrobial evaluation were carried out on the extract. Phytochemical screening revealed the presence of cardiac glycosides, tannins, flavonoids, triterpenes and steroids. Antimicrobial evaluation revealed that the extract is active against Methicillin – resistant Staphylococcus aureus (MRSA), Staphylococcus aureus, Streptococcus pneumoniae, Salmonella typhi, Proteus mirabilis, Shigella dysenteriae, Candida stellatoidea and Candida tropicalis. The zones of inhibition (mm) for the test organisms were (24 - 31) mm. Minimum inhibition concentrations (mg/L) of extract against MRSA, Staphylococcus aureus, Streptococcus pneumonia, Salmonella typhi, Proteus mirabilis, Shigella dysenteriae, Candida stellatoidea and Candida tropicalis were 2.5, 1.25,1.25, 2.5, 1.25, 1.25, 1.25 and 2.5 respectively. Minimum bactericidal concentrations (mg/L) of extract against Methicillin – resistant Staphylococcus aureus (MRSA), Staphylococcus aureus, Streptococcus pneumonia, Salmonella typhi, Proteus mirabilis Shigella dysenteriae Candida stellatoidea and Candida tropicalis were 5, 2.5, 2.5, 5, 5, 2.5,2.5 and 5 respectively. The extract showed high inhibition against MRSA and Candida tropicalis.

High prevalence of OXA-23 carbapenemase-producing Proteus mirabilis among amoxicillin-clavulanate resistant isolates in France

In this multicentric study performed in 12 French hospitals, we reported that 26.9% (14/52) of the amoxicillin/clavulanate-resistant Proteus mirabilis isolates produced the OXA-23 carbapenemase. We found that inhibition zone diameter less than 11 mm around amoxicillin/clavulanate disc was an accurate screening cut-off to detect these OXA-23 producers. We confirmed by whole genome sequencing that these OXA-23-producers all belonged to the same lineage that has been demonstrated to disseminate OXA-23 or OXA-58 in P. mirabilis .

Gram Negative Bacteria (GNB) Isolated From Used Home-made and Surgical Nose/Face Mask by Local Residents of Akungba Akoko, Ondo State, a Threat to Life and False Sense of Protection against SARS-CoV-2 (COVID-19)

Nose/Face masks are physical barriers to respiratory droplets that may enter through the nose and mouth to cause infections in the respiratory tract. The study was determined and assess the presence of Gram-negative bacteria in used home-made and surgical nose mask by residents of Akungba-Akoko Ondo State and to determine the antimicrobial susceptibility and resistant profile of the isolated bacteria to eight (8) different antimicrobial agents. The antimicrobial analysis were performed using standard microbiological and biochemical methods. Antimicrobial Susceptibility test of all identified isolates to antimicrobial agents were determined using the standard Kirby-Bauer disk diffusion method. The Gram-negative bacteria that were detected from the used home-made and surgical nose mask in this study include: Haemophilus influenza, Proteus mirabilis, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumonia. During this study, all the Gram-negative bacteria isolates were resistant to Ciproflox in both used home-made and surgical nose mask. All isolates were also resistant to Ampicilin, Augmentin, Septrin and Streptomycin. In this study, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa were isolated organism from used home-made nose mask, it was observed that Escherichia coli were resistant to Augmentin, Tarivid, Ciproflox, Gentamycin, and Reflaxine, and Pseudomonas aeruginosa were resistant to Tarivid, Ciproflox, and Nalidixic acid between 20 mm and 24 mm zones of inhibition respectively. Haemophilus influenza, Pseudomonas aeruginosa, Escherichia coli and Proteus mirabilis were isolated organism from used surgical nose mask. It was observed that all isolated organisms from the used surgical nose/face mask were resistant to Augmentin and Gentamycin between 20 and 24 mm zones of inhibition respectively. Klebsiella pneumoniae were isolated from both used home-made and surgical nose/face mask and were found to be resistant to Streptomycin, Septrin, Ampicilin, and Gentamicin between 20 to 22 mm zones of inhibition respectively. Proteus mirabilis were isolated from used surgical nose/face mask, they were found to be resistant to Ciproflox at 21mm zones of inhibition. Haemophilus influenza were resistant to Ampicilin, Septrin, Streptomycin, and Augmentin at 23 mm zones of inhibition. Isolates from used both home-made and surgical nose/face mask were subjected to modified and synergized antibiotics, it was observed that the isolates from both used home-made and surgical nose mask were resistant to all modified and synergized antibiotics between 20 and 25 mm zones of inhibition respectively. The result of this study validates the potency of Gram negative bacteria isolated from used both home-made and surgical nose/face mask and the degree of invasion and evasiveness, thereby causing various degrees of infections and a false sense of protection against SARS-CoV-2 (COVID-19). Finding from this research recommends a stringent measures were needed to be implemented, to halt and combat this revenging situation especially in the new era of mutating SARS-CoV-2 Virus not only in Nigeria, worldwide at large.

Virulence genes and antimicrobial resistance pattern in Proteus mirabilis strains isolated from patients attended with urinary infections to Tertiary Hospitals, in Iran

Background: Proteus mirabilis is a frequent reason for catheter-associated urinary tract infections (UTIs). The aim of this study was to identify virulence genes and antimicrobial resistance patterns in P. mirabilis strains isolated from patients whoattended a tertiary hospital in Iran. Methods: In this study, 100 P. mirabilis strains from urine samples were isolated. These isolated strains were identified by biochemical and PCR-based tests, and their antibiotic resistance was profiled through a standard procedure using 14 antibiotics.PCR assays were used to detect virulence-related genes in P. mirabilis strains. The biofilm formation of each P. mirabilis strain was examined. Results: Of the 100 P. mirabilis isolates, 16 (16%) were multidrug-resistant. High resistance was observed against cotrimoxazole (97%), nalidixic acid (93%), cefotaxime (77%), and amoxicillin (62%). Sixty of the 100 isolates showed resistance against extended-spectrum cephalosporins. The prevalence rates of the genes related to the virulence factors in this study were mrpH (100%), ucaA (91%), hpmA (94%), zapA (95%), ptaA (100%), ureG (100%), pmfA (100%), fliC (97%), and mrpA (90%) using PCR method. Strong biofilm formation was observed in 20% (5/25) of the strains isolated fromnon-catheterized samples and 80% (20/25) of strains isolated from catheterized samples. Conclusions: Resistance to antibiotics and the prevalence of pathogenicity genes are high in Proteus mirabilis strains iolated from UTIs. Keywords: Antibiotic resistance; Proteus mirabilis; biofilm; virulence factors.