scholarly journals Molecular characterization of serogroup C Neisseria meningitidis isolated in China

2007 ◽  
Vol 56 (9) ◽  
pp. 1224-1229 ◽  
Author(s):  
Xiaobing Zhang ◽  
Zhujun Shao ◽  
E Yang ◽  
Li Xu ◽  
Xingye Xu ◽  
...  
Keyword(s):  
Bacterial Meningitis ◽  
Neisseria Meningitidis ◽  
Variable Region ◽  
Molecular Characteristics ◽  
Virulent Strains ◽  
Sporadic Cases ◽  
High Level ◽  
Sequence Types ◽  
Close Contacts

An increase in the number of serogroup C meningococcal disease cases occurred in China from September 2003 to January 2006 as a result of several successive outbreaks. In addition, the proportion of serogroup C Neisseria meningitidis isolates from sporadic cases and carriers has also increased. In this study, 113 serogroup C meningococcal isolates were characterized by multilocus sequence typing (MLST) and PorA typing. These isolates comprised those from outbreak cases and their close contacts, the national carriage survey conducted during the same period and some historical isolates from 1966–2002. Twenty MLST sequence types (STs) and 21 PorA variable region (VR) types were identified in the collection. The ST-4821 complex, a newly identified lineage, was the most prevalent lineage (95/113). These data also showed a high level of diversification of serogroup C isolates, as indicated by the number of variants of the ST-4821 clone and the VR types present. There were ten PorA VR types among the ST-4821 isolates, and certain VR types (P1.7-2,14, P1.12-1,16-8) were associated with isolates from outbreak cases. The results of this study allow us to draw a profile of the molecular characteristics of serogroup C strains in China. These data are helpful for monitoring the spread of virulent strains and will provide valuable information for the prevention of bacterial meningitis in China.

scholarly journals Phenotypic and Molecular Characteristics of the MDR Efflux Pump Gene-Carrying Stenotrophomonas maltophilia Strains Isolated in Warsaw, Poland

Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 105
Author(s):  
Olga M. Zając ◽  
Stefan Tyski ◽  
Agnieszka E. Laudy
Keyword(s):  
Molecular Typing ◽  
Stenotrophomonas Maltophilia ◽  
Efflux Pump ◽  
Pulsed Field Gel Electrophoresis ◽  
Molecular Characteristics ◽  
The World ◽  
Genes Encoding ◽  
Resistance Nodulation Division ◽  
Sequence Types

An increase of nosocomial infections caused by Stenotrophomonas maltophilia strains has recently been observed all over the world. The isolation of these bacteria from the blood is of particular concern. In this study we performed the phenotypic and genotypic characterization of 94 S. maltophilia isolates, including isolates from patients hospitalized in a tertiary Warsaw hospital (n = 79) and from outpatients (n = 15). All isolates were found to be susceptible to trimethoprim-sulfamethoxazole and minocycline, while 44/94 isolates demonstrated a reduction in susceptibility to levofloxacin. A large genetic variation was observed among the isolates tested by pulsed-field gel electrophoresis. A clonal relationship with 100% similarity was observed between isolates within two sub-pulsotypes: the first included nine bloodstream isolates and the second involved six. Multilocus sequence typing showed two new sequence types (ST498 and ST499) deposited in public databases for molecular typing. Moreover, the presence of genes encoding ten different efflux pumps from the resistance-nodulation-division family and the ATP-binding cassette family was shown in the majority of the 94 isolates. The obtained knowledge about the prevalence of efflux pump genes in clinical S. maltophilia strains makes it possible to predict the scale of the risk of resistance emergence in strains as a result of gene overexpression.

scholarly journals Molecular Epidemiology of Fosfomycin Resistant E. coli from a Pigeon Farm in China

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 777
Author(s):  
Lu Han ◽  
Xiao-Qing Lu ◽  
Xu-Wei Liu ◽  
Mei-Na Liao ◽  
Ruan-Yang Sun ◽  
...  
Keyword(s):  
Molecular Characteristics ◽  
Genomic Context ◽  
E Coli ◽  
High Prevalence ◽  
Potential Reservoir ◽  
Genomic Environment ◽  
High Level ◽  
Human Infections ◽  
Sequence Types ◽  
Level Resistance

We determined the prevalence and molecular characteristics of fosfomycin-resistant Escherichia coli from a domestic pigeon farm. A total of 79 samples collected from pigeons and their surrounding environments were screened for the presence of fosfomycin resistant isolates and these included 49 E. coli isolates that displayed high-level resistance (MIC ≥ 256 mg L−1) and carried the fosA3 gene on plasmids with sizes ranging from 80 to 370 kb. MLST analysis of these fosA3-positive E. coli isolates indicated the presence of nine sequence types (ST6856, ST8804, ST457, ST746, ST533, ST165, ST2614, ST362 and ST8805) of which ST6856 was the most prevalent (24.5%, 12/49). PFGE combined with genomic context comparative analyses indicated that the fosA3 gene was spread by horizontal transfer as well as via clonal transmission between E. coli in the pigeon farm, and IS26 played an important role in fosA3 transmission. The high prevalence of fosA3 in the pigeon farm and the high similarity of the fosA3 genomic environment between E. coli isolates from humans and pigeons indicated that the pigeon farm served as a potential reservoir for human infections. The pigeon farm was found to be an important reservoir for the fosA3 gene and this should be further monitored.

Characterization of Neisseria meningitidis isolates collected from 1974 to 2003 in Japan by multilocus sequence typing

2004 ◽  
Vol 53 (7) ◽  
pp. 657-662 ◽  
Author(s):  
Hideyuki Takahashi ◽  
Toshiro Kuroki ◽  
Yuko Watanabe ◽  
Hiroshi Tanaka ◽  
Hiroo Inouye ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Neisseria Meningitidis ◽  
Multilocus Sequence Typing ◽  
Clonal Complex ◽  
The Other ◽  
Mlst Database ◽  
Mlst Analysis ◽  
The Past ◽  
Sequence Types

Analysis of 182 Neisseria meningitidis strains isolated over the past 30 years in Japan by serogroup typing and multilocus sequence typing (MLST) was performed. The serogroups of the 182 Japanese isolates were B (103 isolates), Y (39), W135 (1) and non-groupable (39). By MLST analysis, 65 different sequence types (ST) were identified, 42 of which were not found in the MLST database as of January 2004 and seemed to be unique to Japan. Statistical analysis of the MLST results revealed that, although the Japanese isolates seemed to be genetically divergent, they were classified into six major clonal complexes and other minor complexes. Among these isolates, well-documented ST complexes found worldwide were present, such as ST-23 complex (49 isolates), ST-44 complex (41 isolates) and ST-32 complex (8 isolates). On the other hand, a new clonal complex designated ST-2046 complex (28 isolates), which has not been identified in other countries, was also found, suggesting that this clone was indigenous to Japan. Taken together, it was speculated that meningococcal isolates in Japan comprised heterogeneous clones, which were derived both from clones identified in other countries and clones unique to Japan.

scholarly journals Antibiotic Susceptibility and Characteristics of Neisseria meningitidis Isolates from the African Meningitis Belt, 2000 to 2006: Phenotypic and Genotypic Perspectives

2009 ◽  
Vol 53 (4) ◽  
pp. 1561-1566 ◽  
Author(s):  
Sara Thulin Hedberg ◽  
Hans Fredlund ◽  
Pierre Nicolas ◽  
Dominique A. Caugant ◽  
Per Olcén ◽  
...  
Keyword(s):  
Neisseria Meningitidis ◽  
Antibiotic Susceptibility ◽  
Penicillin G ◽  
African Countries ◽  
Antibiotic Susceptibilities ◽  
Meningitis Belt ◽  
High Level ◽  
Sequence Types ◽  
Selection Of ◽  
Allele Identification

ABSTRACT Up-to-date information regarding the antibiotic susceptibility of Neisseria meningitidis strains from African countries is highly limited. Our aim was to comprehensively describe the antibiotic susceptibilities of a selection of N. meningitidis isolates recovered between 2000 and 2006 from 18 African countries, mainly those within the meningitis belt. Susceptibilities to 11 antibiotics were determined using Etest for 137 N. meningitidis isolates (stringently selected from 693 available isolates). The isolates were also characterized by serogrouping, multilocus sequence typing, genosubtyping, and penA allele identification. All N. meningitidis isolates were susceptible to ceftriaxone, chloramphenicol, and ciprofloxacin. No isolate produced β-lactamase. Only three isolates (2%) displayed reduced susceptibility to penicillin G. The two isolates with the highest penicillin G MICs were the only isolates showing reduced susceptibility to ampicillin and cefuroxime. One of these isolates was also resistant to penicillin V. One percent of isolates displayed reduced susceptibility to rifampin, while 52% of the isolates were resistant to tetracycline, 74% were resistant to erythromycin, and 94% were resistant to sulfadiazine. The MICs of rifampin and tetracycline seemed to be associated with the serogroup of the isolates. In total, 18 sequence types (STs), 10 genosubtypes, and 8 different penA alleles were identified; the most common were ST-7, P1.20,9,35-1, and penA4, respectively. A high level of correlation was found between ST, genosubtype, and penA allele. In conclusion, N. meningitidis isolates from the African meningitis belt remain highly susceptible to the antibiotics used. Regarding β-lactam antibiotics, rare isolates showed a reduced susceptibility to penicillins, but the expanded-spectrum cephalosporins are not affected at present.

scholarly journals Increasing Resistance to Azithromycin inNeisseria gonorrhoeaein Eastern Chinese Cities: Resistance Mechanisms and Genetic Diversity among Isolates from Nanjing

2018 ◽  
Vol 62 (5) ◽  
Author(s):  
Chuan Wan ◽  
Yang Li ◽  
Wen-Jing Le ◽  
Yu-Rong Liu ◽  
Sai Li ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Resistance Mechanisms ◽  
23S Rrna ◽  
Molecular Characteristics ◽  
Chinese Cities ◽  
Content Type ◽  
Public Health Challenge ◽  
High Level ◽  
Level Resistance

ABSTRACTAzithromycin resistance (AZM-R) ofNeisseria gonorrhoeaeis emerging as a clinical and public health challenge. We determined molecular characteristics of recent AZM-R Nanjing gonococcal isolates and tracked the emergence of AZM-R isolates in eastern Chinese cities in recent years. A total of 384N. gonorrhoeaeisolates from Nanjing collected from 2013 to 2014 were tested for susceptibility to AZM and six additional antibiotics; all AZM-R strains were characterized genetically for resistance determinants by sequencing and were genotyped usingN. gonorrhoeaemultiantigen sequence typing (NG-MAST). Among the 384 isolates, 124 (32.3%) were AZM-R. High-level resistance (MIC, ≥256 mg/liter) was present in 10.4% (40/384) of isolates, all of which possessed the A2143G mutation in all four 23S rRNA alleles. Low- to mid-level resistance (MIC, 1 to 64 mg/liter) was present in 21.9% (84/384) of isolates, 59.5% of which possessed the C2599T mutation in all four 23S rRNA alleles. The 124 AZM-R isolates were distributed in 71 different NG-MAST sequence types (STs). ST1866 was the most prevalent type in high-level AZM-R (HL-AZM-R) isolates (45% [18/40]). This study, together with previous reports, revealed that the prevalence of AZM-R inN. gonorrhoeaeisolates in certain eastern Chinese cities has risen >4-fold (7% to 32%) from 2008 to 2014. The principal mechanisms of AZM resistance in recent Nanjing isolates were A2143G mutations (high-level resistance) and C2599T mutations (low- to mid-level resistance) in the 23S rRNA alleles. Characterization of NG-MAST STs and phylogenetic analysis indicated the genetic diversity ofN. gonorrhoeaein Nanjing; however, ST1866 was the dominant genotype associated with HL-AZM-R isolates.

scholarly journals The Dissemination and Molecular Characterization of Clonal Complex 361 (CC361) Methicillin-Resistant Staphylococcus aureus (MRSA) in Kuwait Hospitals

2021 ◽  
Vol 12 ◽  
Author(s):  
Eiman Sarkhoo ◽  
Edet E. Udo ◽  
Samar S. Boswihi ◽  
Stefan Monecke ◽  
Elke Mueller ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Genetic Relatedness ◽  
Clonal Complex ◽  
Molecular Characteristics ◽  
Virulence Determinants ◽  
Related Sequence ◽  
Methicillin Resistant ◽  
Linezolid Resistance ◽  
Sequence Types

Methicillin-resistant Staphylococcus aureus (MRSA) belonging to clonal complex 361 (CC361-MRSA) is rare among patients’ populations globally. However, CC361-MRSA has been isolated with an increasing trend among patients in Kuwait hospitals since 2010. This study investigated the molecular characteristics of CC361-MRSA isolated from patients in Kuwait hospitals in 2016–2018 to understand their genetic relatedness and virulence determinants. Of 5,223 MRSA isolates investigated by DNA microarray, 182 (3.4%) isolates obtained in 2016 (N = 55), 2017 (N = 56), and 2018 (N = 71) were identified as CC361-MRSA. The CC361-MRSA isolates were analyzed further using antibiogram, spa typing and multi locus sequence typing (MLST). Most of the isolates were resistant to fusidic acid (64.8%), kanamycin (43.4%), erythromycin (36.3%), and clindamycin (14.3%) encoded by fusC, aphA3, and erm(B)/erm(C) respectively. Nine isolates (4.9%) were resistant to linezolid mediated by cfr. The isolates belonged to 22 spa types with t3841 (N = 113), t315 (N = 16), t1309 (N = 14), and t3175 (N = 5) constituting 81.3% of the spa types, four genotypes (strain types), CC361-MRSA-[V/VT + fus] (N = 112), CC361-MRSA-IV, WA MRSA-29 (N = 36), CC361-MRSA-V, WA MRSA-70/110 (N = 33) and CC361-MRSA-[V + fus] variant (N = 1). MLST conducted on 69 representative isolates yielded two sequence types: ST361 (11/69) and ST672 (58/69). All CC361-MRSA isolates were positive for cap8, agr1, and the enterotoxin egc gene cluster (seg, sei, selm, seln, selo, and selu). The tst1 was detected in 19 isolates. The immune evasion cluster (IEC) genes type B (scn, chp, and sak) and type E (scn and sak) were detected in 20 and 152 isolates, respectively. The CC361-MRSA circulating in Kuwait hospitals consisted of two closely related sequence types, ST361 and ST672 with ST672-MRSA [V/VT + fus] as the dominant genotype. The dissemination of these newly emerged clones and the emergence of linezolid resistance limits therapeutic options, as well as present significant challenges for the control of MRSA infections in Kuwait hospitals.

scholarly journals Genotypic characterization and genome comparison reveal insights into potential vaccine coverage and genealogy of Neisseria meningitidis in military camps in Vietnam

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9502
Author(s):  
Trang Thu Le ◽  
Thach Xuan Tran ◽  
Long Phi Trieu ◽  
Christopher M. Austin ◽  
Huong Minh Nguyen ◽  
...  
Keyword(s):  
Neisseria Meningitidis ◽  
Vaccine Coverage ◽  
Molecular Data ◽  
Genome Comparison ◽  
Molecular Characteristics ◽  
Military Unit ◽  
The Military ◽  
Epidemiological Characteristics ◽  
Military Units ◽  
Sequence Types

Background Neisseria meningitidis remains the main cause of sporadic meningitis and sepsis in military camps in Vietnam. Yet, very limited molecular data of their genotypic and epidemiological characteristics are available from Vietnam, and particularly the military environment. Whole genome sequencing (WGS) has proven useful for meningococcal disease surveillance and guiding preventative vaccination programs. Previously, we characterized key genetic and epidemiological features of an invasive N. meningitidis B isolate from a military unit in Vietnam. Here, we extend these findings by sequencing two additional invasive N. meningitidis B isolated from cerebrospinal fluid (CSF) of two meningitis cases at another military unit and compared their genomic sequences and features. We also report the sequence types and antigenic profiles of 25 historical and more recently emerged N. meningitidis isolates from these units and other units in proximity. Methods Strains were sequenced using the Illumina HiSeq platform, de novo assembled and annotated. Genomes were compared within and between military units, as well as against the global N. meningitidis collection and other isolates from the Southeast Asia region using PubMLST. Variations at the nucleotide level were determined, and phylogenetic relationships were estimated. Antigenic genotypes and vaccine coverage were analyzed using gMATS and PubMLST. Susceptibility of isolates against commonly used antibiotic agents was examined using E-test. Results Genome comparison revealed a high level of similarity among isolates both within and between units. All isolates showed resistance to chloramphenicol and carried identical catP gene with other Southeast Asian isolates, suggesting a common lineage. Their antigenic genotypes predicted no coverage by either Bexsero®or Trumenba®, and nucleotide variation analysis revealed diverse new, unassigned alleles at multiple virulence loci of all strains. Groups of singleton and unique novel sequence types extending beyond individual camps were found from epidemiological data of 25 other isolates. Our results add to the sparse published molecular data of N. meningitidis in the military units in Vietnam, highlight their diversity, distinct genetic features and antibiotic resistance pattern, and emphasize the need for further studies on the molecular characteristics of N. meningitidis in Vietnam.

scholarly journals The genetic characteristics of Neisseria meningitidis causing invasive meningococcal infections in Smolensk region

2020 ◽  
Vol 22 (2) ◽  
pp. 92-95
Author(s):  
Konstantin O. Mironov ◽  
E.A. Yarygina ◽  
Aida Chagaryan ◽  
Nataly Ivanchik
Keyword(s):  
Cerebrospinal Fluid ◽  
Neisseria Meningitidis ◽  
Outer Membrane ◽  
Multilocus Sequence Typing ◽  
Outer Membrane Proteins ◽  
Variable Region ◽  
Russian Regions ◽  
Meningococcal Infections ◽  
Genetic Characteristics ◽  
Sequence Types

Objective. To determine antigenic and genetic characteristics of Neisseria meningitidis isolated from the patients with invasive meningococcal infections in Smolensk region in comparison with those circulating in other regions. Materials and Methods. A total of 14 cerebrospinal fluid samples obtained in 2016–2019 and containing N. meningitidis DNA were tested using AmpliSens® Nm-ABCW kit, multilocus sequence typing and antigenic finetyping of outer membrane proteins. The results were analyzed by the BURST algorithm and other functionalities available at PubMLST.org (Jolley K. et al. 2018). Results. The variable region alleles, sequence types and clonal complexes were determined for the tested isolates. The genotyping results were published in the PubMLST database (https://pubmlst.org/neisseria/). Most of N. meningitidis serogroup B isolates (n = 6) belonged to sequence types which have not been described previously: ST-14705, ST-14710, ST-14711, ST-14713 and ST-14717. Sequence types of serogroup C isolates (n = 7) were usual for strains circulating in other Russian regions (4 of 7 belonged to ST-8416). The only serogroup Y isolate belonged to ST-11585. Conclusions. Most studied N. meningitidis sequence types belonged to clonal complexes designated in PubMLST database and groups of isolates, determined by the BURST algorithm, which were usual for Russian regions. The antigenic and genetic characteristics suggest no circulation of epidemiologically significant N. meningitidis strains or hypervirulent strains on the observed territory.

Sign in / Sign up

Export Citation Format

Share Document