Mutation of TonB-Dependent Receptor Encoding Gene MCR_0492 Potentially Associates with Macrolides Resistance in Moraxella catarrhalis Isolates

Abstract

Introduction Moraxella catarrhalis , which is an opportunistic pathogen and is one of the three major pathogens of community-acquired pneumonia, causes a variety of infections in clinic. In recent years, the isolation rate of Moraxella catarrhalis has gradually increased. In China, due to the clinical empirical use of antibiotics, the resistance rate of Moraxella catarrhalis isolated from children to β-lactam antibiotics has reached 99%. The non-susceptible rate of Moraxella catarrhalis to macrolide antibiotics has also increased significantly. Methods Two isolates of Moraxella catarrhalis (R17123922_R and R18013231_R) were isolated from in-patients and were confirmed to be resistant to macrolide antibiotics using the standard disk diffusion and broth microdilution method recommended by CLSI. Whole-genome sequencing (WGS) analysis was performed in these two resistant strains. Results A total of 696 SNVs (single nucleotide variations), and 79 indels (Insertion and Deletion) were found in R17123922_R and R18013231_R. These SNVs and indels were distributed evenly in the genome, and no centralized distribution occurred. Moreover, two isolates did not harbor any previously reported mutations in the 23S rRNA and ribosomal proteins. Conclusion A novel indel in the MCR_0492 gene encoding TonB-dependent receptor protein was identified, and we speculated that TonB-dependent protein receptor may play an important role in macrolide resistance of Moraxella catarrhalis .

Characterization of two novel colistin resistance gene mcr-1 variants originated from Moraxella spp.

“…In addition to colistin resistance genes ( mcr-1.10 , mcr-1.35 , mcr-1.36 , mcr-2.2 , and mcr-6.1 ), Moraxella spp. also carried genes for β-lactam resistance ( bla BRO-1 and bla BRO-2 ) aminoglycoside resistance ( aac(3)-IId , aac(3)-IV , aph(2″)-If , aph(3′)-Ia , aph(3″)-Ib , and aph(6)-Id ); tetracycline resistance [ tet (B), tet (D), tet (L), and tet (O)]; chloramphenicol resistance ( floR ), sulfonamide resistance ( sul2 ), and macrolide resistance ( erm T) ( Flamm et al, 2012 ; AbuOun et al, 2017 ; Krol-Turminska et al, 2020 ; Raveendran et al, 2020 ; Zhang et al, 2022 ). In recent studies, Moraxella spp.…”

“…In recent studies, Moraxella spp. from human samples have proven to be mainly resistant to β-lactam, tetracycline, and macrolide ( Flamm et al, 2012 ; Krol-Turminska et al, 2020 ; Raveendran et al, 2020 ; Zhang et al, 2022 ). The three Moraxella spp.…”

“…In addition to colistin resistance genes, Moraxella spp. are also known to contain ampicillin, penicillin, quinolone, macrolide, and tetracycline resistance genes, among others ( Flamm et al, 2012 ; AbuOun et al, 2017 ; Krol-Turminska et al, 2020 ; Raveendran et al, 2020 ; Zhang et al, 2022 ). Bacteria of the genus Moraxella are aerobic, rod-shaped, opportunistic Gram-negative pathogens ( Vela et al, 2010 ; Embers et al, 2011 ).…”

An integrated complete-genome sequencing and systems biology approach to predict antimicrobial resistance genes in the virulent bacterial strains of Moraxella catarrhalis

“…In addition to this, the exterior layer porin M35 of M. catarrhalis is the factor that determines whether or not the bacteria are susceptible to aminopenicillins [ 24 ]. The resistance frequency of M. catarrhalis identified in infants to Beta-lactam antibiotics has attained 99% in China as a result of therapeutic experimental usage of antibiotics [ 25 ]. Furthermore, according to reports, M. catarrhalis appeared extremely susceptible to macrolide antibiotics, erythromycin and rokitamycin [ 25 , 26 ].…”

“…The resistance frequency of M. catarrhalis identified in infants to Beta-lactam antibiotics has attained 99% in China as a result of therapeutic experimental usage of antibiotics [ 25 ]. Furthermore, according to reports, M. catarrhalis appeared extremely susceptible to macrolide antibiotics, erythromycin and rokitamycin [ 25 , 26 ]. In addition, some investigations have demonstrated that M. catarrhalis is sensitive to the antibiotics cefaclor, clarithromycin, azithromycin, doxycycline, co-trimoxazole, cefuroxime, cefixime and ceftriaxone, as well as ofloxacin and ciprofloxacin [ 27 ].…”