Multilocus Sequence Typing Sequence Types Research Articles

Molecular characterisation of Mycoplasma bovis isolates from consecutive episodes of respiratory disease on Dutch veal farms

Mycoplasma bovis infections are wide spread in veal calf farms and a major contributor to respiratory disease. M. bovis are genetically diverse. It is unclear how this diversity influences the virulence and epidemiology of infections on veal calf farms over time. Therefore, the aim of this study was to follow the genetic composition of M. bovis isolates on veal farms over time in a fattening round and combine this with presence of disease and presence of other respiratory pathogens. For this, M. bovis isolates were obtained from healthy and diseased calves from ten different farms at different episodes of respiratory disease in the same groups in one fattening round. A new episode of respiratory disease was defined by the practitioner based on clinical diagnosis at least 7 days after end of a previous metaphylactic treatment. These isolates were sequenced using Illumina sequencing and analysed. This resulted in 148 sequenced isolates. The isolates belonged to 9 different clusters and to the known MLST sequence types ST4 (n=9), ST6 (n=2), ST7 (n=1), ST8 (n=1), ST21 (n=32), ST29 (n=30), ST32 (n=1), ST100 (n=36), ST122 (n=17) and ST135 (n=4), and new sequence types ST222 (n=8), ST223 (n=1), ST224 (n=5) and ST225 (n=1). Major sequence types are linked to types, found in other European countries. All farms showed presence of two or more different clusters, however with different distribution patterns. Farms did not show a major shift in type distribution over time. There was a relationship between M. bovis type and region of origin of the calves and the types differed with regards of presence of variable membrane surface lipoprotein (Vsp) genes. Types were not related to disease status of the calves or presence of other major respiratory pathogens. This study underlines the complexity of M. bovis infection on veal calf farms with persistent presence of different types together in both healthy and diseased calves with or without other respiratory pathogens. Prevention of introduction of M. bovis and biosecurity measures combined with optimisation of calf resilience should have priority.

Genomic study of European Clostridioides difficile ribotype 002/sequence type 8.

Clostridioides difficile has significant clinical importance as a leading cause of healthcare-associated infections, with symptoms ranging from mild diarrhoea to severe colitis, and possible life-threatening complications. C. difficile ribotype (RT) 002, mainly associated with MLST sequence type (ST) 8, is one of the most common RTs found in humans. This study aimed at investigating the genetic characteristics of 537 C. difficile genomes of ST8/RT002. To this end, we sequenced 298 C. difficile strains representing a new European genome collection, with strains from Germany, Denmark, France and Portugal. These sequences were analysed against a global dataset consisting of 1,437 ST8 genomes available through Enterobase. Our results showed close genetic relatedness among the studied ST8 genomes, a diverse array of antimicrobial resistance (AMR) genes and the presence of multiple mobile elements. Notably, the pangenome analysis revealed an open genomic structure. ST8 shows relatively low overall variation. Thus, clonal isolates were found across different One Health sectors (humans, animals, environment and food), time periods, and geographical locations, suggesting the lineage's stability and a universal environmental source. Importantly, this stability did not hinder the acquisition of AMR genes, emphasizing the adaptability of this bacterium to different selective pressures. Although only 2.4 % (41/1,735) of the studied genomes originated from non-human sources, such as animals, food, or the environment, we identified 9 cross-sectoral core genome multilocus sequence typing (cgMLST) clusters. Our study highlights the importance of ST8 as a prominent lineage of C. difficile with critical implications in the context of One Health. In addition, these findings strongly support the need for continued surveillance and investigation of non-human samples to gain a more comprehensive understanding of the epidemiology of C. difficile.

Genomic characterization of Listeria monocytogenes and Listeria innocua isolated from milk and dairy samples in Ethiopia

Listeriosis caused by Listeria monocytogenes often poses a significant threat to vulnerable populations. Dairy products have been implicated in outbreaks of listeriosis worldwide. In Ethiopia, studies have identified Listeria spp. and L. monocytogenes in various dairy products, but the genetic diversity and phylogenetic relationships of these bacteria remain largely unknown in the low- and middle-income countries. Therefore, we conducted whole-genome sequencing on 15 L. monocytogenes and 55 L. innocua isolates obtained from different levels of the dairy supply chains across three regions in Ethiopia. Genomes were assembled and used for MLST genotyping and single nucleotide polymorphism (SNP) analysis to infer phylogenetic relationships. We identified a total of 3 L. monocytogenes (i.e., 2, 145, and 18) and 12 L. innocua (i.e., 1489, 1619, 603, 537, 1010, 3186, 492, 3007, 1087, 474, 1008, and 637) MLST sequence types among the studied isolates. Some of these sequence types showed region-specific occurrence, while others were broadly distributed across regions. Through high-quality SNP analysis, we found that among 13 L. monocytogenes identified as ST 2, 11 of them were highly similar with low genetic variation, differing by only 1 to 10 SNPs, suggesting potential selection in the dairy food supply chain. The L. innocua isolates also exhibited low intra-ST genetic variation with only 0–10 SNP differences, except for the ST 1619, which displayed a greater diversity.

High Genetic Diversity in Third-Generation Cephalosporin-Resistant Escherichia coli in Wastewater Systems of Schleswig-Holstein.

The spread of multidrug-resistant bacteria from humans or livestock is a critical issue. However, the epidemiology of resistant pathogens across wastewater pathways is poorly understood. Therefore, we performed a detailed comparison of third-generation cephalosporin-resistant Escherichia coli (3GCREC) from wastewater treatment plants (WWTPs) to analyze dissemination pathways. A total of 172 3GCREC isolated from four WWTPs were characterized via whole genome sequencing. Clonal relatedness was determined using multi-locus sequence typing (MLST) and core genome MLST. Resistance genotypes and plasmid replicons were determined. A total of 68 MLST sequence types were observed with 28 closely related clusters. Resistance genes to eight antibiotic classes were detected. In fluoroquinolone-resistant isolates, resistance was associated with three-or-more point mutations in target genes. Typing revealed high genetic diversity with only a few clonal lineages present in all WWTPs. The distribution paths of individual lines could only be traced in exceptional cases with a lack of enrichment of certain lineages. Varying resistance genes and plasmids, as well as fluoroquinolone resistance-associated point mutations in individual isolates, further corroborated the high diversity of 3GCREC in WWTPs. In total, we observed high diversity of 3GCREC inside the tested WWTPs with proof of resistant strains being released into the environment even after treatment processes.

Australian Meningococcal Surveillance Programme Annual Report, 2022.

In Australia, both probable and laboratory-confirmed cases of invasive meningococcal disease (IMD) are reported to the National Notifiable Diseases Surveillance System (NNDSS). Compared to 2021, the number of IMD notifications in 2022 increased by 81% to 127, alongside the easing of COVID-19 containment measures. Laboratory confirmation occurred in 95% of these cases, with 51% (62/121) diagnosed by bacterial culture and 49% (59/121) by nucleic acid amplification testing. The serogroup was determined for 97% of laboratory-confirmed cases (117/121): serogroup B (MenB) accounted for 83% of infections (100/121); MenW for 4% (5/121); MenY for 10% (12/121); no infections were attributed to MenC disease. Fine typing was available on 67% of the cases for which the serogroup was determined (78/117). In MenB isolates, 27 porA types were detected, the most prevalent of which were P1.7-2,4 (18%;11/62), P1.22,14 (15%; 9/62), P1.18-1,34 (10%; 6/62) and P1.7,16-26 (10%; 6/62). All five MenW infections identified as porA type P1.5,2 with different MLST sequence types (ST): 11, 574, 1287, 12351, 13135 all belonging to clonal complex 11, the hypervirulent strain reported in outbreaks in Australia and overseas. In MenY, the predominant porA type was P1.5-1,10-1 (73%; 8/11), ST 1655 and from clonal complex 23. Children less than 5 years of age and people aged 15-19 years were overrepresented with IMD notifications, accounting for 22% (27/121) and 23% (28/121) of laboratory-confirmed cases respectively. Fifteen percent of laboratory-confirmed notifications (18/121) were in persons aged 45-64 years. MenB infections were detected in all age groups but predominated in persons aged 15-19 years (93% of IMD in this age group; 26/28) and comprised 89% (24/27) of infections in children aged less than 5 years. MenW infections were markedly reduced in 2022, accounting for two IMD detections in children 1-4 years (2/16) and sporadic detections in other older age groups. MenY infections were largely detected in adults aged 45-64 years, accounting for 28% of IMD in this age group (5/18). All 62 cultured IMD isolates had antimicrobial susceptibility testing performed. Minimum inhibitory concentration (MIC) values were categorised using Clinical Laboratory Standards Institute (CLSI) interpretative criteria: 5% (3/62) were defined as penicillin resistant (MIC value ≥ 0.5 mg/L); 71% (44/62) had intermediate susceptibility to penicillin (MIC values 0.125 and 0.25 mg/L) and 24% (15/62) were susceptible to penicillin. All isolates were susceptible to ceftriaxone, ciprofloxacin and rifampicin.

International Clones of High Risk of Acinetobacter Baumannii-Definitions, History, Properties and Perspectives.

Acinetobacter baumannii is a Gram-negative coccobacillus with exceptional survival skills in an unfavorable environment and the ability to rapidly acquire antibiotic resistance, making it one of the most successful hospital pathogens worldwide, representing a serious threat to public health. The global dissemination of A. baumannii is driven by several lineages named 'international clones of high risk' (ICs), two of which were first revealed in the 1970s. Epidemiological surveillance is a crucial tool for controlling the spread of this pathogen, which currently increasingly involves whole genome sequencing. However, the assignment of a particular A. baumannii isolate to some IC based on its genomic sequence is not always straightforward and requires some computational skills from researchers, while the definitions found in the literature are sometimes controversial. In this review, we will focus on A. baumannii typing tools suitable for IC determination, provide data to easily determine IC assignment based on MLST sequence type (ST) and intrinsic blaOXA-51-like gene variants, discuss the history and current spread data of nine known ICs, IC1-IC9, and investigate the representation of ICs in public databases. MLST and cgMLST profiles, as well as OXA-51-like presence data are provided for all isolates available in GenBank. The possible emergence of a novel A. baumannii international clone, IC10, will be discussed.

Prevalence of ciprofloxacin resistance and associated genetic determinants differed among Campylobacter isolated from human and poultry meat sources in Pennsylvania

Poultry is the primary source of Campylobacter infections and severe campylobacteriosis cases are treated with macrolides and fluoroquinolones. However, these drugs are less effective against antimicrobial-resistant strains. Here, we investigated the prevalence of phenotypic antimicrobial resistance and associated resistance genetic determinants in Campylobacter isolates collected from human clinical (N = 123) and meat (N = 80) sources in Pennsylvania in 2017 and 2018. Our goal was to assess potential differences in the prevalence of antimicrobial resistance in Campylobacter isolated from human and poultry meat sources in Pennsylvania and to assess the accuracy of predicting antimicrobial resistance phenotypes based on resistance genotypes. We whole genome sequenced isolates and identified genetic resistance determinants using the National Antimicrobial Resistance Monitoring System Campylobacter AMR workflow v2.0 in GalaxyTrakr. Phenotypic antimicrobial susceptibility testing was carried out using the E-Test and Sensititre CAMPYCMV methods for human clinical and poultry meat isolates, respectively, and the results were interpreted using the EUCAST epidemiological cutoff values. The 193 isolates were represented by 85 MLST sequence types and 23 clonal complexes, suggesting high genetic diversity. Resistance to erythromycin was confirmed in 6% human and 4% meat isolates. Prevalence of ciprofloxacin resistance was significantly higher in human isolates as compared to meat isolates. A good concordance was observed between phenotypic resistance and the presence of the corresponding known resistance genetic determinants.

Tolerance of clinical vancomycin-resistant Enterococcus faecium isolates against UV-C light from a mobile source

BackgroundAdmission to a room previously occupied by patients carrying environmentally robust pathogens implies an increased risk of acquiring those pathogens. Therefore, ‘No-touch’ automated room disinfection systems, including devices based on UV-C irradiation, are discussed to improve terminal cleaning. It is still unclear if clinical isolates of relevant pathogens behave differently under UV-C irradiation compared to laboratory strains used in the approval process of disinfection procedures. In this study we analysed the susceptibility of well characterized clonally divergent vancomycin-resistant enterococci (VRE) strains, including a linezolid-resistant isolate, against UV-C radiation.MethodsSusceptibility against UV-C of ten clonally divergent clinical isolates of VRE was determined in comparison to the commonly used test organism Enterococcus hirae ATCC 10541. Ceramic tiles contaminated with 105 to 106 colony forming units/25 cm² of the different enterococci were positioned at a distance of 1.0 and 1.5 m and irradiated for 20 s, resulting in a UV-C dose of 50 and 22 mJ/cm², respectively. Reduction factors were calculated after quantitative culture of the bacteria recovered from treated and untreated surfaces.ResultsSusceptibility to UV-C varied considerably among the strains studied, with the mean value of the most robust strain being up to a power of ten lower compared to the most sensitive strain at both UV-C doses. The two most tolerant strains belonged to MLST sequence types ST80 and ST1283. The susceptibility of the laboratory strain E. hirae ATCC 10541 ranged between the most sensitive and most tolerant isolates for both irradiation doses. However, for UV-C dose of 22 mJ/cm², the reduction of the most tolerant isolate of ST1283 was statistically significantly lower compared to E. hirae ATCC 10541. The most susceptible strains belonged to the MLST sequence types ST117 and ST203.ConclusionsThese results indicate that UV-C doses reported in the literature are sufficient for the reduction of commonly used reference strains of enterococci but could be insufficient for the reduction of tolerant patient VRE-isolates in a hospital setting. Therefore, for future studies, the most tolerant clinical isolates should be used to validate automated UV-C devices or longer exposure times should be expected to ensure efficacy in the real world.

Trends in invasive Haemophilus influenzae serotype a disease in England from 2008–09 to 2021–22: a prospective national surveillance study

Invasive Haemophilus influenzae serotype a (Hia) disease is rare, with most cases reported among Indigenous populations in North America. In England, national surveillance was enhanced following an increase in laboratory-confirmed invasive Hia disease since the 2016-17 epidemiological year. This study aimed to describe the epidemiological trends, clinical characteristics of cases, and assess potential genomic drivers. Hospital laboratories in England routinely submit invasive H influenzae isolates to the UK Health Security Agency for confirmation and serotyping. In this prospective national surveillance study we contacted the general practitioners and clinicians of all patients with laboratory-confirmed invasive Hia from the 2008-09 to the 2021-22 epidemiological year to complete a clinical questionnaire on demographics, underlying conditions, clinical presentation, complications, outcomes, and travel history of the patient. All Hia invasive isolates from residents in England were included in the study; non-invasive isolates were excluded. Multilocus sequence typing (MLST), whole genome single-nucleotide polymorphism, and k-mer-based analysis of bacterial isolates were performed following Illumina whole-genome sequencing (WGS). Outcomes included epidemiological trends, clinical characteristics of confirmed Hia cases, and genomic analyses. From the 2008-09 to the 2021-22 epidemiological years, there were 52 cases of invasive infection with H influenzae serotype a in England (25 [48%] in female patients and 27 [52%] in male patients). There were zero to two annual Hia cases (accounting for <0·5% of serotyped H influenzae isolates) until 2015-16, after which cases increased across England to 19 cases in 2021-22 (incidence 0·03 cases per 100 000), when Hia accounted for 19 (4%) of 484 serotyped H influenzae isolates, 19 (19%) of 100 capsulated cases, and 37% (19 of 52) of all H influenzae cases between 2008-09 and 2021-22. Most of the recent increase in cases occurred among individuals aged 65 years and older (17 [33%] of 52), who typically presented with bacteraemic pneumonia (13 [76%] of 17), and infants younger than 1 year, who had the highest incidence and were more likely to present with meningitis (five [50%] of ten). Overall case fatality rate was 7·7% (95% CI 2·1-19·7; four of 52 patients). WGS found that closely related MLST sequence types ST1511 (20 [39%] of 51), ST23 (13 [25%] of 51), and ST56 (seven [14%] of 51) accounted for most cases, with no evidence of serotype b strains switching capsule to Hia. Duplication of the capsule operon, associated with more severe disease, was present in 32 (80%) of 40 of these sequence types. Analysis of the core and accessory genome content grouped most isolates into a single strain. The persistent increase in invasive Hia cases across England and across all age groups suggests widespread transmission, consistent with reports from other European countries, and will require close monitoring. UK Health Security Agency.

Pharyngeal Communities and Antimicrobial Resistance in Pangolins in Gabon.

Wildlife can be a reservoir and source of zoonotic pathogens for humans. For instance, pangolins were considered one of the potential animal reservoirs of SARS-CoV-2. The aim of this study was to assess the prevalence of antimicrobial-resistant species (e.g., extended-spectrum β-lactamase [ESBL]-producing Enterobacterales) and Staphylococcus aureus-related complex and to describe the bacterial community in wild Gabonese pangolins. The pharyngeal colonization of pangolins sold in Gabon (n = 89, 2021 to 2022) was analyzed using culture media selective for ESBL-producing Enterobacterales, S. aureus-related complex, Gram-positive bacteria and nonfermenters. Phylogenetic analyses of ESBL-producing Enterobacterales was done using core-genome multilocus sequence typing (cgMLST) and compared with publicly available genomes. Patterns of cooccurring species were detected by network analysis. Of the 439 bacterial isolates, the majority of species belonged to the genus Pseudomonas (n = 170), followed by Stenotrophomonas (n = 113) and Achromobacter (n = 37). Three Klebsiella pneumoniae isolates and one Escherichia coli isolate were ESBL-producers, which clustered with human isolates from Nigeria (MLST sequence type 1788 [ST1788]) and Gabon (ST38), respectively. Network analysis revealed a frequent cooccurrence of Stenotrophomonas maltophilia with Pseudomonas putida and Pseudomonas aeruginosa. In conclusion, pangolins can be colonized with human-related ESBL-producing K. pneumoniae and E. coli. Unlike in other African wildlife, S. aureus-related complex was not detected in pangolins. IMPORTANCE There is an ongoing debate if pangolins are a relevant reservoir for viruses such as SARS-CoV-2. Here, we wanted to know if African pangolins are colonized with bacteria that are relevant for human health. A wildlife reservoir of antimicrobial resistance would be of medical relevance in regions were consumption of so-called bushmeat is common. In 89 pangolins, we found three ESBL-producing Klebsiella pneumoniae strains and one ESBL-producing Escherichia coli strains, which were closely related to isolates from humans in Africa. This points toward either a transmission between pangolins and humans or a common source from which both humans and pangolins became colonized.

High prevalence of clonally related ST182 NDM-1-producing Enterobacter cloacae complex clinical isolates in Greece

NDM-type metallo-β-lactamase (MBL)-producing Enterobacterales remain uncommon in the European region, especially among species other than Klebsiella pneumoniae and Escherichia coli. The aim of this study was to describe epidemiological and molecular characteristics of a widespread NDM-1-producing Enterobacter cloacae complex outbreak in Greece. Over a 6-year period (March 2016-March 2022), a retrospective study was conducted in a tertiary care Greek hospital. Ninety single-patient carbapenem-non-susceptible E. cloacae complex clinical isolates were recovered consecutively. The isolates were subjected to further investigation, including antimicrobial susceptibility testing and combined disc tests for carbapenemase production, polymerase chain reaction and sequencing for resistance genes, molecular fingerprinting by pulsed-field gel electrophoresis (PFGE), plasmid profiling, replicon typing, conjugation experiments, genotyping by multi-locus sequence typing (MLST), whole-genome sequencing and phylogenetic analysis. Phenotypic and molecular testing confirmed the presence of blaNDM-1 in 47 (52.2%) of the E. cloacae complex isolates. MLST analysis clustered all but four of the NDM-1 producers into a single MLST sequence type (ST182), whereas single isolates belonged to different sequence types (ST190, ST269, ST443 and ST743). PFGE analysis revealed that ST182 isolates were clustered into a single clonal type, with three subtypes, which differed from the clonal types detected among the remaining carbapenem non-susceptible E. cloacae complex isolates identified during the study period. All ST182 blaNDM-1-carrying isolates also harboured the blaACT-16 AmpC gene, while the blaESBL, blaOXA-1 and blaTEM-1 genes were detected in most cases. In all clonal isolates, the blaNDM-1 gene was located on an IncA/C-type plasmid, and flanked upstream by an ISAba125 element and downstream by bleMBL. Conjugation experiments failed to produce carbapenem-resistant transconjugants, indicating a low dynamic for horizontal gene transfer. Application of enforced infection control measures led to the absence of new NDM-positive cases for periods of time during the survey. This study represents the largest clonal outbreak of NDM-producing E. cloacae complex in Europe.

Avian Chlamydia abortus Strains Detected in Galápagos Waved Albatross (Phoebastria irrorata).

Galápagos Penguin (Spheniscus mendiculus), Flightless Cormorant (Phalacrocorax harrisi), and Waved Albatross (Phoebastria irrorata) are among the most vulnerable species to natural and anthropogenic factors in the Galápagos Islands. In 2017, a dedicated study was conducted to detect Chlamydiaceae on cloacal swabs collected from 59 albatrosses, 68 penguins, and 10 cormorants in different islands and sites in the Galápagos Archipelago. A real-time PCR method targeting the conserved 23S ribosomal RNA gene of the Chlamydiaceae family detected the presence of the bacterium only in albatrosses from Punta Suárez, Española Island, with 21 positive samples (35.6%), whereas negative results were obtained with available real-time PCR systems specific to Chlamydia psittaci and Chlamydia abortus. Multilocus sequence typing (MLST) of the most strongly positive samples revealed a new sequence type closely related to the recently described avian strains of C. abortus. For a quick identification, a new real-time PCR system that allows the detection of all strains (avian and ruminant) belonging to the C. abortus species has been developed. Applied to a second set of samples from 31 albatrosses collected at Punta Suárez, Española Island, in 2018, the new real-time PCR system confirmed the presence of this bacteria in this group of birds, with the same new MLST sequence type.

Large Multicountry Outbreak of Invasive Listeriosis by a Listeria monocytogenes ST394 Clone Linked to Smoked Rainbow Trout, 2020 to 2021.

Whole-genome sequencing (WGS) has revolutionized surveillance of infectious diseases. Disease outbreaks can now be detected with high precision, and correct attribution of infection sources has been improved. Listeriosis, caused by the bacterium Listeria monocytogenes, is a foodborne disease with a high case fatality rate and a large proportion of outbreak-related cases. Timely recognition of listeriosis outbreaks and precise allocation of food sources are important to prevent further infections and to promote public health. We report the WGS-based identification of a large multinational listeriosis outbreak with 55 cases that affected Germany, Austria, Denmark, and Switzerland during 2020 and 2021. Clinical isolates formed a highly clonal cluster (called Ny9) based on core genome multilocus sequence typing (cgMLST). Routine and ad hoc investigations of food samples identified L. monocytogenes isolates from smoked rainbow trout filets from a Danish producer grouping with the Ny9 cluster. Patient interviews confirmed consumption of rainbow trout as the most likely infection source. The Ny9 cluster was caused by a MLST sequence type (ST) ST394 clone belonging to molecular serogroup IIa, forming a distinct clade within molecular serogroup IIa strains. Analysis of the Ny9 genome revealed clpY, dgcB, and recQ inactivating mutations, but phenotypic characterization of several virulence-associated traits of a representative Ny9 isolate showed that the outbreak strain had the same pathogenic potential as other serogroup IIa strains. Our report demonstrates that international food trade can cause multicountry outbreaks that necessitate cross-border outbreak collaboration. It also corroborates the relevance of ready-to-eat smoked fish products as causes for listeriosis. IMPORTANCE Listeriosis is a severe infectious disease in humans and characterized by an exceptionally high case fatality rate. The disease is transmitted through consumption of food contaminated by the bacterium Listeria monocytogenes. Outbreaks of listeriosis often occur but can be recognized and stopped through implementation of whole-genome sequencing-based pathogen surveillance systems. We here describe the detection and management of a large listeriosis outbreak in Germany and three neighboring countries. This outbreak was caused by rainbow trout filet, which was contaminated by a L. monocytogenes clone belonging to sequence type ST394. This work further expands our knowledge on the genetic diversity and transmission routes of an important foodborne pathogen.

Isolation and multilocus sequence typing of Borrelia burgdorferi from Ixodes scapularis collected from dogs in Ontario, Canada

ObjectiveTo identify the multilocus sequence typing (MLST) sequence types of Borrelia burgdorferi from Ixodes scapularis in Ontario, Canada.ResultsOne hundred and eighty-five I. scapularis ticks were submitted from 134 dogs via participating clinics from April 1, 2019, to March 31, 2020. Seventeen MLST sequence types of B. burgdorferi were detected from fifty-eight cultured isolates from 21 ticks. The most common MLST sequence types were 12 and 16. Mixed infections of two MLST sequence types were detected in four ticks. Three sequence types (48, 317, 639) were new detections in Ontario.

Diversity of NG-MAST and MLST Sequence Types in Russian Clinical Isolates of Neisseria gonorrhoeae Carrying the “Mosaic” Allele of the penA Gene

Diversity of NG-MAST and MLST Sequence Types in Russian Clinical Isolates of Neisseria gonorrhoeae Carrying the “Mosaic” Allele of the penA Gene

Whole-Genome Sequence Comparisons of Listeria monocytogenes Isolated from Meat and Fish Reveal High Inter- and Intra-Sample Diversity.

Interpretation of whole-genome sequencing (WGS) data for foodborne outbreak investigations is complex, as the genetic diversity within processing plants and transmission events need to be considered. In this study, we analyzed 92 food-associated Listeria monocytogenes isolates by WGS-based methods. We aimed to examine the genetic diversity within meat and fish production chains and to assess the applicability of suggested thresholds for clustering of potentially related isolates. Therefore, meat-associated isolates originating from the same samples or processing plants as well as fish-associated isolates were analyzed as distinct sets. In silico serogrouping, multilocus sequence typing (MLST), core genome MLST (cgMLST), and pangenome analysis were combined with screenings for prophages and genetic traits. Isolates of the same subtypes (cgMLST types (CTs) or MLST sequence types (STs)) were additionally compared by SNP calling. This revealed the occurrence of more than one CT within all three investigated plants and within two samples. Analysis of the fish set resulted in predominant assignment of isolates from pangasius catfish and salmon to ST2 and ST121, respectively, potentially indicating persistence within the respective production chains. The approach not only allowed the detection of distinct subtypes but also the determination of differences between closely related isolates, which need to be considered when interpreting WGS data for surveillance.

Australian Meningococcal Surveillance Programme Annual Report, 2021.

Invasive meningococcal disease (IMD) is a notifiable disease in Australia, with both probable and laboratory-confirmed cases of IMD reportable to the National Notifiable Diseases Surveillance System (NNDSS). In 2021, there were 74 notifications of IMD made, the lowest number recorded since 1991 when records began. Ninety-one percent of notified cases (67/74) were laboratory confirmed, with 69% of laboratory-confirmed cases (46/67) diagnosed by bacterial culture and 31% (21/67) by nucleic acid amplification testing. The serogroup was determined for 63/67 laboratory-confirmed cases (94%): serogroup B (MenB) accounted for 52% of infections (35/67); MenW for 22% (15/67); MenY for 19% (13/67); there were no infections attributed to MenC. Fine typing was available on 37/67 (55%) where the serogroup was determined. The greatest variability was in MenB, with nine different porA types represented. All MenW infections belonged to a single porA type (P1.5,2) with five different MLST sequence types represented: 11, 574, 1287, 12351, 13135; all belonged to clonal complex 11, the hypervirulent strain reported in recent outbreaks in Australia and overseas. All MenY were from the same porA antigen type, P1.5-1,10-1: MLST sequence type 1655; clonal complex 23. Peaks occurred in children less than 5 years, reaching 24% (16/67) of reported cases, and in those aged 15-19 years reaching 16% (11/67) of reported cases. It is notable that 15% (10/67) of notifications were in persons aged 45-64 years, and an equivalent proportion (15%; 10/67) in adults aged 65 years and above. MenB infections predominated in persons aged 15-19 years (100%, 11/11), and comprised 56% (9/16) of infections in children aged less than 5 years. By contrast, Men W infections accounted for half (5/10) of IMD detections in infants less than 1 year, and 30% (3/10) of infections in persons aged 45-65 years. MenY infections predominated in adults aged 65 years and greater, resulting in 70% (7/10) of IMD in this age group. All 46 IMD isolates had antimicrobial susceptibility testing performed. Minimum inhibitory concentration (MIC) values were categorised using Clinical Laboratory Standards Institute (CLSI) interpretative criteria: 13% (6/46) were defined as penicillin resistant (MIC value, ≥ 0.5 mg/L); 59% (27/46) had intermediate susceptibility to penicillin (MIC values, 0.125 and 0.25 mg/L) and 28% (13/46) were susceptible to penicillin. All isolates were susceptible to ceftriaxone and rifampicin. A single MenB IMD isolate from New South Wales exhibited ciprofloxacin resistance (MIC value, 0.125 mg/L).

Genotyping of Burkholderia pseudomallei Isolated From Patients in South-Western Coastal Region of India

Burkholderia pseudomallei is the causative agent of melioidosis. Various tools have been used to determine the genetic diversity in B. pseudomallei isolates. In this study, Random Amplified Polymorphic DNA (RAPD)-PCR and flagellin gene (fliC) based PCR-Restriction Fragment Length Polymorphism (RFLP) were used to genotype Indian clinical B. pseudomallei isolates. A total of 89 clinical isolates could be grouped in 6 groups (A through F) by RAPD-PCR analysis. Some of the isolates in various groups had identical banding pattern suggesting them to be epidemiologically related. The RAPD groups also correlated with MLST sequence types suggesting the utility of this easy to do typing method. The PCR- RFLP analysis suggested Type III to be the predominant type which is different from other RFLP types reported from Southeast Asia. In conclusion, the results of this study show that RAPD-PCR, a simple genotyping method, may be used for analyzing the B. pseudomallei isolates and also establish epidemiological relevant relatedness among them. The results of fliC PCR-RFLP further suggest the Indian isolates are different from other Southeast Asian isolates.

Genomic Characterization of Mobile Genetic Elements Associated With Carbapenem Resistance of Acinetobacter baumannii From India.

With the excessive genome plasticity, Acinetobacter baumannii can acquire and disseminate antimicrobial resistance (AMR) genes often associated with mobile genetic elements (MGEs). Analyzing the genetic environment of resistance genes often provides valuable information on the origin, emergence, evolution, and spread of resistance. Thus, we characterized the genomic features of some clinical isolates of carbapenem-resistant A. baumannii (CRAb) to understand the role of diverse MGEs and their genetic context responsible for disseminating carbapenem resistance genes. For this, 17 clinical isolates of A. baumannii obtained from multiple hospitals in India between 2018 and 2019 were analyzed. AMR determinants, the genetic context of resistance genes, and molecular epidemiology were studied using whole-genome sequencing. This study observed an increased prevalence of blaOXA–23 followed by dual carbapenemases, blaOXA–23, and blaNDM. This study identified three novel Oxford MLST sequence types. The majority of the isolates belonged to the dominant clone, IC2, followed by less prevalent clones such as IC7 and IC8. This study identified variations of AbaR4 and AbGRI belonging to the IC2 lineage. To the best of our knowledge, this is the first study that provides comprehensive profiling of resistance islands, their related MGEs, acquired AMR genes, and the distribution of clonal lineages of CRAb from India.

Dogs as carriers of virulent and resistant genotypes of Clostridioides difficile.

While previous research on zoonotic transmission of community‐acquired Clostridioides difficile infection (CA‐CDI) focused on food‐producing animals, the present study aimed to investigate whether dogs are carriers of resistant and/or virulent C. difficile strains. Rectal swabs were collected from 323 dogs and 38 C. difficile isolates (11.8%) were obtained. Isolates were characterized by antimicrobial susceptibility testing, whole‐genome sequencing (WGS) and a DNA hybridization assay. Multilocus sequence typing (MLST), core genome MLST (cgMLST) and screening for virulence and antimicrobial resistance genes were performed based on WGS. Minimum inhibitory concentrations for erythromycin, clindamycin, tetracycline, vancomycin and metronidazole were determined by E‐test. Out of 38 C. difficile isolates, 28 (73.7%) carried genes for toxins. The majority of isolates belonged to MLST sequence types (STs) of clade I and one to clade V. Several isolates belonged to STs previously associated with human CA‐CDI. However, cgMLST showed low genetic relatedness between the isolates of this study and C. difficile strains isolated from humans in Austria for which genome sequences were publicly available. Four isolates (10.5%) displayed resistance to three of the tested antimicrobial agents. Isolates exhibited resistance to erythromycin, clindamycin, tetracycline and metronidazole. These phenotypic resistances were supported by the presence of the resistance genes erm(B), cfr(C) and tet(M). All isolates were susceptible to vancomycin. Our results indicate that dogs may carry virulent and antimicrobial‐resistant C. difficile strains.