Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 1.439
Filter
1.
Saudi Med J ; 45(5): 458-467, 2024 May.
Article in English | MEDLINE | ID: mdl-38734425

ABSTRACT

The aim of this study was to go through the molecular methods used for typing of carbapenem-resistant Acientobacter baumannii (CRAB) isolates for investigating the molecular epidemiology all over the world. Multiple typing techniques are required to understand the source and nature of outbreaks caused by Acientobacter baumannii (A. baumannii) and acquired resistance to antimicrobials. Nowadays, there is gradual shift from traditional typing methods to modern molecular methods to study molecular epidemiology and infection control. Molecular typing of A. baumannii strains has been revolutionized significantly in the last 2 decades. A few sequencing-based techniques have been proven as a breakthrough and opened new prospects, which have not been achieved by the traditional methods. In this review, discussed different pre-existing and recently used typing methods to explore the molecular epidemiology of A. baumannii pertaining in context with human infections.


Subject(s)
Acinetobacter Infections , Acinetobacter baumannii , Molecular Epidemiology , Molecular Typing , Acinetobacter baumannii/genetics , Acinetobacter baumannii/isolation & purification , Humans , Molecular Epidemiology/methods , Acinetobacter Infections/epidemiology , Acinetobacter Infections/microbiology , Molecular Typing/methods , Bacterial Typing Techniques/methods
2.
PLoS Negl Trop Dis ; 18(4): e0012143, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38662795

ABSTRACT

Trachoma is the leading infectious cause of blindness worldwide and is now largely confined to around 40 low- and middle-income countries. It is caused by Chlamydia trachomatis (Ct), a contagious intracellular bacterium. The World Health Organization recommends mass drug administration (MDA) with azithromycin for treatment and control of ocular Ct infections, alongside improving facial cleanliness and environmental conditions to reduce transmission. To understand the molecular epidemiology of trachoma, especially in the context of MDA and transmission dynamics, the identification of Ct genotypes could be useful. While many studies have used the Ct major outer membrane protein gene (ompA) for genotyping, it has limitations. Our study applies a typing system novel to trachoma, Multiple Loci Variable Number Tandem Repeat Analysis combined with ompA (MLVA-ompA). Ocular swabs were collected post-MDA from four trachoma-endemic zones in Ethiopia between 2011-2017. DNA from 300 children with high Ct polymerase chain reaction (PCR) loads was typed using MLVA-ompA, utilizing 3 variable number tandem repeat (VNTR) loci within the Ct genome. Results show that MLVA-ompA exhibited high discriminatory power (0.981) surpassing the recommended threshold for epidemiological studies. We identified 87 MLVA-ompA variants across 26 districts. No significant associations were found between variants and clinical signs or chlamydial load. Notably, overall Ct diversity significantly decreased after additional MDA rounds, with a higher proportion of serovar A post-MDA. Despite challenges in sequencing one VNTR locus (CT1299), MLVA-ompA demonstrated cost-effectiveness and efficiency relative to whole genome sequencing, providing valuable information for trachoma control programs on local epidemiology. The findings suggest the potential of MLVA-ompA as a reliable tool for typing ocular Ct and understanding transmission dynamics, aiding in the development of targeted interventions for trachoma control.


Subject(s)
Bacterial Outer Membrane Proteins , Chlamydia trachomatis , Genotype , Minisatellite Repeats , Trachoma , Chlamydia trachomatis/genetics , Chlamydia trachomatis/isolation & purification , Chlamydia trachomatis/classification , Trachoma/epidemiology , Trachoma/microbiology , Trachoma/drug therapy , Humans , Ethiopia/epidemiology , Minisatellite Repeats/genetics , Bacterial Outer Membrane Proteins/genetics , Female , Male , Child, Preschool , Molecular Typing/methods , Azithromycin/therapeutic use , Genetic Variation , Infant , Child , Anti-Bacterial Agents/pharmacology , DNA, Bacterial/genetics
3.
Mol Biol Rep ; 51(1): 416, 2024 Mar 13.
Article in English | MEDLINE | ID: mdl-38478145

ABSTRACT

INTRODUCTION: Klebsiella pneumoniae is an opportunistic pathogen which is an important cause of hospital-acquired and antibiotic resistance infections. Therefore, this study aimed to determine the frequency of resistance to antibiotics, as well as the molecular typing of the associated isolates, and compare multiple-locus VNTR analysis (MLVA) and Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction (ERIC-PCR) methods to specify the degree to which distinctions can be separated from each other. METHODS AND MATERIALS: One hundred K. pneumoniae isolates were obtained from different sources of infections from patients admitted to hospitals. Antibiotic susceptibility testing was then performed by applying the Kirby-Bauer disk diffusion method. Typing of K. pneumoniae was done by utilizing MLVA and ERIC-PCR methods. RESULTS: Eighty-six multidrug-resistant (MDR) K. pneumoniae isolates were identified, which resistance to ampicillin, trimethoprim/sulfamethoxazole, and ceftriaxone was the most frequent in the considered isolates (100, 93, and 93%, respectively). A total of 50 different antibiotic susceptibility patterns were observed among the MDR K. pneumonia, with the most frequent pattern being resistance to all antibiotics (12.79%) and resistance to all antibiotics except amikacin (10.47%). The isolates were then divided into 37 different MLVA types and seven clonal complexes were obtained from the minimum spanning tree analysis. Finally, the isolates were assigned to 38 different ERIC types. The discriminatory power of MLVA and ERIC methods also showed a value of 0.958, and 0.974. CONCLUSION: Both PCR-typing methods with phenotypic patterns can be useful for the epidemiological typing of K. pneumoniae isolates with the highest performance in discriminating isolates.


Subject(s)
Klebsiella Infections , Klebsiella pneumoniae , Humans , Klebsiella pneumoniae/genetics , Klebsiella Infections/drug therapy , Klebsiella Infections/epidemiology , Klebsiella Infections/microbiology , Microbial Sensitivity Tests , Molecular Typing/methods , Anti-Bacterial Agents/pharmacology , Enterobacteriaceae
5.
J Appl Microbiol ; 134(3)2023 Mar 01.
Article in English | MEDLINE | ID: mdl-36801995

ABSTRACT

AIMS: The ability to distinguish between Klebsiella pneumoniae strains is critical for outbreak investigations. A new typing method, intergenic region polymorphism analysis (IRPA), was developed, validated, and the discriminatory power was determined by comparison with multiple-locus variable-number tandem repeat analysis (MLVA) in this study. METHODS AND RESULTS: This method is based on the idea that every IRPA locus (polymorphic fragment of intergenic regions present in one strain but not in other strains or different fragment sizes in other strains) could divide strains into different genotypes. A 9-loci IRPA scheme was designed to type 64 K. pneumoniae isolates. Five IRPA loci were identified that conferred the same level of discrimination as the 9-loci initially examined. Among these K. pneumoniae isolates, 7.81% (5/64), 6.25% (4/64), 4.96% (3/64), 9.38% (6/64), and 1.56% (1/64) were capsular serotypes K1, K2, K5, K20, and K54, respectively. The discriminatory power of the IRPA method was better than that of MLVA expressed in Simpson's index of diversity (SI) at 0.997 and 0.988, respectively. The congruent analysis of the IRPA method and MLVA showed moderate congruence between the two methods (AR = 0.378). The AW indicated that if IRPA data are availabl, one can accurately predict the MLVA cluster. CONCLUSION: The IRPA method was found to have higher discriminatory power than MLVA and allowed for simpler band profile interpretation. The IRPA method is a rapid, simple, and high-resolution technique for molecular typing of K. pneumoniae.


Subject(s)
Genotyping Techniques , Klebsiella pneumoniae , Genotype , Klebsiella pneumoniae/genetics , Genotyping Techniques/methods , Molecular Typing/methods , Minisatellite Repeats/genetics
6.
PLoS One ; 17(3): e0264682, 2022.
Article in English | MEDLINE | ID: mdl-35235585

ABSTRACT

Global and local whole genome sequencing of SARS-CoV-2 enables the tracing of domestic and international transmissions. We sequenced Viral RNA from 37 sampled Covid-19 patients with RT-PCR-confirmed infections across the UAE and developed time-resolved phylogenies with 69 local and 3,894 global genome sequences. Furthermore, we investigated specific clades associated with the UAE cohort and, their global diversity, introduction events and inferred domestic and international virus transmissions between January and June 2020. The study comprehensively characterized the genomic aspects of the virus and its spread within the UAE and identified that the prevalence shift of the D614G mutation was due to the later introductions of the G-variant associated with international travel, rather than higher local transmissibility. For clades spanning different emirates, the most recent common ancestors pre-date domestic travel bans. In conclusion, we observe a steep and sustained decline of international transmissions immediately following the introduction of international travel restrictions.


Subject(s)
COVID-19/transmission , COVID-19/virology , Infection Control/methods , SARS-CoV-2/genetics , Travel/statistics & numerical data , Adolescent , Adult , Aged , COVID-19/epidemiology , Child , Child, Preschool , Female , Genome, Viral/genetics , Humans , Male , Middle Aged , Molecular Typing/methods , Mutation , Phylogeny , RNA, Viral , SARS-CoV-2/isolation & purification , Sequence Analysis, RNA , Travel-Related Illness , United Arab Emirates/epidemiology , Whole Genome Sequencing , Young Adult
7.
Microbiol Spectr ; 10(1): e0181721, 2022 02 23.
Article in English | MEDLINE | ID: mdl-35138156

ABSTRACT

Staphylococcus aureus is a major bacterial human pathogen that causes a wide variety of clinical manifestations. The main aim of the presented study was to determine and optimize a novel sequencing independent approach that enables molecular typing of S. aureus isolates and elucidates the transmission of emergent clones between patients. In total, 987 S. aureus isolates including both methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) isolates were used to evaluate the novel typing approach combining high-resolution melting (HRM) analysis of multilocus sequence typing (MLST) genes (mini-MLST) and spa gene (spa-HRM). The novel approach's discriminatory ability was evaluated by whole-genome sequencing (WGS). The clonal relatedness of tested isolates was set by the BURP and BURST approach using spa and MLST data, respectively. Mini-MLST classified the S. aureus isolates into 38 clusters, followed by spa-HRM classifying the isolates into 101 clusters. The WGS proved HRM-based methods to effectively differentiate between related S. aureus isolates. Visualizing evolutionary relationships among different spa-types provided by the BURP algorithm showed comparable results to MLST/mini-MLST clonal clusters. We proved that the combination of mini-MLST and spa-HRM is rapid, reproducible, and cost-efficient. In addition to high discriminatory ability, the correlation between spa evolutionary relationships and mini-MLST clustering allows the variability in population structure to be monitored. IMPORTANCE Rapid and cost-effective molecular typing tools for Staphylococcus aureus epidemiological applications such as transmission tracking, source attribution and outbreak investigations are highly desirable. High-resolution melting based methods are effective alternative to those based on sequencing. Their good reproducibility and easy performance allow prospective typing of large set of isolates while reaching great discriminatory power. In this study, we established a new epidemiological approach to S. aureus typing. This scheme has the potential to greatly improve epidemiological investigations of S. aureus.


Subject(s)
Bacterial Typing Techniques/methods , Infection Control , Molecular Typing/methods , Staphylococcus aureus/genetics , Staphylococcus aureus/isolation & purification , Humans , Methicillin-Resistant Staphylococcus aureus/genetics , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Multilocus Sequence Typing , Prospective Studies , Reproducibility of Results , Staphylococcal Infections/diagnosis , Staphylococcal Infections/microbiology , Staphylococcus aureus/classification , Whole Genome Sequencing
8.
J Nanobiotechnology ; 20(1): 41, 2022 Jan 21.
Article in English | MEDLINE | ID: mdl-35062978

ABSTRACT

Early detection of viral pathogens by DNA-sensors in clinical samples, contaminated foods, soil or water can dramatically improve clinical outcomes and reduce the socioeconomic impact of diseases such as COVID-19. Clustered regularly interspaced short palindromic repeat (CRISPR) and its associated protein Cas12a (previously known as CRISPR-Cpf1) technology is an innovative new-generation genomic engineering tool, also known as 'genetic scissors', that has demonstrated the accuracy and has recently been effectively applied as appropriate (E-CRISPR) DNA-sensor to detect the nucleic acid of interest. The CRISPR-Cas12a from Prevotella and Francisella 1 are guided by a short CRISPR RNA (gRNA). The unique simultaneous cis- and trans- DNA cleavage after target sequence recognition at the PAM site, sticky-end (5-7 bp) employment, and ssDNA/dsDNA hybrid cleavage strategies to manipulate the attractive nature of CRISPR-Cas12a are reviewed. DNA-sensors based on the CRISPR-Cas12a technology for rapid, robust, sensitive, inexpensive, and selective detection of virus DNA without additional sample purification, amplification, fluorescent-agent- and/or quencher-labeling are relevant and becoming increasingly important in industrial and medical applications. In addition, CRISPR-Cas12a system shows great potential in the field of E-CRISPR-based bioassay research technologies. Therefore, we are highlighting insights in this research direction.


Subject(s)
CRISPR-Cas Systems/physiology , DNA, Viral/isolation & purification , Nucleic Acid Amplification Techniques , Animals , Biosensing Techniques/methods , Biosensing Techniques/trends , COVID-19/virology , DNA, Viral/analysis , Environmental Pollutants/analysis , Environmental Pollutants/isolation & purification , Food Contamination/analysis , Humans , Molecular Typing/methods , Molecular Typing/trends , Nucleic Acid Amplification Techniques/methods , Nucleic Acid Amplification Techniques/trends , SARS-CoV-2/genetics , Virology/methods , Virology/trends , Virus Diseases/classification , Virus Diseases/diagnosis , Virus Diseases/virology
9.
World J Microbiol Biotechnol ; 38(2): 19, 2022 Jan 06.
Article in English | MEDLINE | ID: mdl-34989896

ABSTRACT

Winemaking is a complex process involving two successive fermentations: alcoholic fermentation, by yeasts, and malolactic fermentation (MLF), by lactic acid bacteria (LAB). During MLF, LAB can contribute positively to wine flavor through decarboxylation of malic acid with acidity reduction and other numerous enzymatic reactions. However, some microorganisms can have a negative impact on the quality of the wine through processes such as biogenic amine production. For these reasons, monitoring the bacterial community profiles during MLF can predict and control the quality of the final product. In addition, the selection of LAB from a wine-producing area is necessary for the formulation of native malolactic starter cultures well adapted to local winemaking practices and able to enhance the regional wine typicality. In this sense, molecular biology techniques are fundamental tools to decipher the native microbiome involved in MLF and to select bacterial strains with potential to function as starter cultures, given their enological and technological characteristics. In this context, this work reviews the different molecular tools (both culture-dependent and -independent) that can be applied to the study of MLF, either in bacterial isolates or in the microbial community of wine, and of its dynamics during the process.


Subject(s)
Fermentation , Lactobacillales , Microbiota/genetics , Molecular Typing/methods , Wine/microbiology , Biodiversity , Lactobacillales/classification , Lactobacillales/genetics , Lactobacillales/metabolism , Malates/metabolism , Microbiological Techniques , RNA, Ribosomal, 16S/genetics , Whole Genome Sequencing , Yeasts
10.
J Clin Lab Anal ; 36(1): e24117, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34837715

ABSTRACT

BACKGROUND: Candida albicans is the most common and virulent genus Candida. Detection of virulence factors in this species plays an important role in the better understanding of pathogenesis and antifungal treatment. Molecular typing investigations are important in the epidemiological interpretation of infection. This study aimed to evaluate extracellular enzyme activity and genotyping of C. albicans species isolated from vulvovaginal samples. METHODS: One hundred and three vaginal C. albicans isolates were tested for esterase, phospholipase, proteinase, and hemolysin activities by specific media. Besides, the DNA of C. albicans isolates was extracted and amplified for ABC genotyping. RESULTS: The highest enzyme production of C. albicans isolates was for proteinase (97.1%) and esterase (95.2%), whereas 59.2% of C. albicans isolates were negative for hemolysin secretion. Genotype C (83.5%) was the most frequent genotype followed by genotype B (12.6%) and genotype A (3.9%). CONCLUSION: It is concluded that genotype C was the predominant genotype in all examined vulvovaginal C. albicans isolates. Also, there was a significant difference between enzyme production in each genotype (except for proteinase).


Subject(s)
Candida albicans , Candidiasis, Vulvovaginal/microbiology , Genotyping Techniques/methods , Molecular Typing/methods , Candida albicans/enzymology , Candida albicans/genetics , Candida albicans/pathogenicity , Female , Fungal Proteins/genetics , Genotype , Humans , Virulence Factors/genetics
11.
J Clin Lab Anal ; 36(1): e24154, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34850984

ABSTRACT

BACKGROUND: There is limited research assessing the utility of the Xpert Mycobacterium tuberculosis/rifampin (MTB/RIF) assay for the analysis of bronchoalveolar lavage fluid (BALF) in Chinese patients with suspected pulmonary tuberculosis (PTB). Thus, our objective was to determine the diagnostic accuracy of the Xpert MTB/RIF assay and evaluate its utility for the determination of rifampicin resistance. METHODS: We retrospectively analyzed BALF from 214 patients with suspected PTB between January 2018 and March 2019. Using mycobacterial culture or final clinical diagnosis as the reference standard, the diagnostic accuracy of the smear microscopy (SM), tuberculosis bacillus DNA (TB-DNA), Xpert MTB/RIF assay, and the determination of rifampicin resistance based on the Xpert MTB/RIF assay were compared. RESULTS: As compared to mycobacterial culture, the sensitivity of the Xpert MTB/RIF assay, SM, and TB-DNA were 85.5% (74.2%-93.1%), 38.7% (26.6%-51.9%), and 67.7% (54.7%-79.1%), respectively. As compared to the final diagnosis, the specificity of the Xpert MTB/RIF assay, SM, and TB-DNA were 100.0% (95.9%-100.0%), 94.3% (87.1%-98.1%), and 98.9% (93.8%-100.0%), respectively. The sensitivity and specificity of the rifampicin resistance detection using the Xpert MTB/RIF assay were 100% and 98.0%, respectively, with liquid culture as the reference. CONCLUSIONS: This study demonstrates that the analysis of BALF with the Xpert MTB/RIF assay provides a rapid and accurate tool for the early diagnosis of PTB. The accuracy of diagnosis was superior compared with the SM and TB-DNA. Moreover, Xpert is a quick and accurate method for the diagnosis of rifampicin-resistant tuberculosis and can also provide more effective guidance for the treatment of PTB or multidrug-resistant tuberculosis (MDR-TB).


Subject(s)
Drug Resistance, Multiple, Bacterial/genetics , Molecular Typing/methods , Mycobacterium tuberculosis , Tuberculosis, Pulmonary/diagnosis , Adult , Antibiotics, Antitubercular/pharmacology , Bronchoalveolar Lavage Fluid/microbiology , Female , Humans , Male , Middle Aged , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/genetics , Retrospective Studies , Rifampin/pharmacology , Tuberculosis, Multidrug-Resistant/diagnosis , Tuberculosis, Multidrug-Resistant/microbiology , Tuberculosis, Pulmonary/microbiology
13.
Microbiol Spectr ; 9(3): e0124221, 2021 12 22.
Article in English | MEDLINE | ID: mdl-34937187

ABSTRACT

The taxonomy of the genus Enterobacter can be confusing and has been considerably revised in recent years. We propose a PCR and amplicon sequencing technique based on a partial sequence of the dnaJ gene for species assignment consistent with DNA-DNA digital hybridization (dDDH) and pairwise average nucleotide identity (ANI). We performed a validation of the method by comparing the type strains of each species, sequences obtained from the GenBank database, and clinical specimens. Our results show that the polymorphism of the target sequence of dnaJ allows the identification of species. Using this gene, we assigned the species to 100 strains deposited in the GenBank database that were consistent with the species assignment by dDDH and ANI. The analysis showed that using the partial dnaJ sequence is congruent with WGS as far as correct identification of Enterobacter species is concerned. Finally, we applied our dnaJ method on a national collection of 68 strains identified as Enterobacter isolated from the blood cultures of premature babies using an algorithm based on a type-strain library and the SeqScape software. For the first time, we identified Enterobacter quasihormaechei in blood cultures from four neonatal sepsis cases. We also noticed a higher prevalence of E. bugandensis (36.3%; 32/88) and E. xiangfangensis (46.5%; 41/88). E. bugandensis is a novel species recently described specifically in instances of neonatal sepsis. In conclusion, sequencing a part of the dnaJ gene could be a quick, more economical, and highly discriminating method of identifying Enterobacter species in clinical practice and research. IMPORTANCE We propose a new approach for Enterobacter species identification based on the diversity of the gene encoding the heat shock protein DnaJ. This new tool can be easily implemented in clinical laboratories in addition to identification by MALDI-TOF.


Subject(s)
Enterobacter/classification , Enterobacter/genetics , Enterobacteriaceae Infections/diagnosis , HSP40 Heat-Shock Proteins/genetics , Molecular Typing/methods , Algorithms , Base Sequence , DNA, Bacterial/genetics , Enterobacter/isolation & purification , Enterobacteriaceae Infections/microbiology , Genes, Essential/genetics , Humans , Infant, Newborn , Polymerase Chain Reaction/methods , Polymorphism, Single Nucleotide/genetics , RNA, Ribosomal, 16S/genetics , Sepsis/diagnosis , Sepsis/microbiology , Sequence Analysis, DNA
14.
PLoS Negl Trop Dis ; 15(11): e0009982, 2021 11.
Article in English | MEDLINE | ID: mdl-34847144

ABSTRACT

PCR-based methods to amplify the 3' untranslated region (3'-UTR) of the heat shock protein 70 (type I) gene (HSP70-I) have previously been used for typing of Leishmania but not with Leishmania (Mundinia) martiniquensis and L. (Mundinia) orientalis, newly identified human pathogens. Here, the 3'-UTRs of HSP70-I of L. martiniquensis, L. orientalis, and 10 other species were sequenced and analyzed. PCR-Restriction Fragment Length Polymorphism (RFLP) analysis targeting the 3'-UTR of HSP70-I was developed. Also, the detection limit of HSP70-I-3'-UTR PCR methods was compared with two other commonly used targets: the 18S small subunit ribosomal RNA (SSU-rRNA) gene and the internal transcribed spacer 1 region of the rRNA (ITS1-rRNA) gene. Results showed that HSP70-I-3'-UTR PCR methods could be used to identify and differentiate between L. martiniquensis (480-2 bp) and L. orientalis (674 bp) and distinguished them from parasites of the subgenus Viannia and of the subgenus Leishmania. PCR-RFLP patterns of the 3'-UTR of HSP70-I fragments digested with BsuRI restriction enzyme successfully differentiated L. martiniquensis, L. orientalis, L. braziliensis, L. guyanensis = L. panamensis, L. mexicana = L. aethiopica = L. tropica, L. amazonensis, L. major, and L. donovani = L. infantum. For the detection limit, the HSP70-I-3'-UTR PCR method could detect the DNA of L. martiniquensis and L. orientalis at the same concentration, 1 pg/µL, at a similar level to the SSU-rRNA PCR. The PCR that amplified ITS1-rRNA was more sensitive (0.01 pg/µL) than that of the HSP70-I-3'-UTR PCR. However, the sizes of both SSU-rRNA and ITS1-rRNA PCR amplicons could not differentiate between L. martiniquensis and L. orientalis. This is the first report of using HSP70-I-3'-UTR PCR based methods to identify the parasites causing leishmaniasis in Thailand. Also, the BsuRI-PCR-RFLP method can be used for differentiating some species within other subgenera.


Subject(s)
3' Untranslated Regions , HSP70 Heat-Shock Proteins/genetics , Leishmania/genetics , Leishmania/isolation & purification , Leishmaniasis/parasitology , Molecular Typing/methods , Polymerase Chain Reaction/methods , Protozoan Proteins/genetics , Humans , Leishmania/classification , Thailand
16.
Microbiol Spectr ; 9(3): e0121421, 2021 12 22.
Article in English | MEDLINE | ID: mdl-34787484

ABSTRACT

In Aspergillus fumigatus, the repetitive region of the csp1 gene is one of the most frequently used loci for intraspecies typing of this human pathogenic mold. Using PCR amplification and Sanger sequencing of only a single marker, csp1 typing is readily available to most laboratories and highly reproducible. Here, I evaluate the usefulness of the csp1 marker for resistance detection and epidemiologic stratification among A. fumigatus isolates. After resolving nomenclature conflicts from published studies and adding novel csp1 types, the number of known types now adds up to 38. Their distribution mostly correlates with A. fumigatus population structure, and they are also meaningful for narrowly defined cases of azole resistance phenotypes. Isolates carrying the pandemic resistance allele TR34/L98H show signs of interclade crossing of strains with t02 or t04A, into the t11 clade. Furthermore, absolute differences in voriconazole MIC values between t02/t04B versus t11 TR34/L98H isolates indicate that the genetic background of resistance mutations may have a pivotal role in cross-resistance phenotypes and, thus, clinical outcome and environmental selection. Despite the general genetic similarity of isolates with identical csp1 types, outcrossing into other clades is also observed. The csp1 type alone, therefore, does not sufficiently discriminate genetic clades to be used as the sole marker in epidemiologic studies. IMPORTANCE Aspergillus fumigatus is a ubiquitously distributed saprophytic mold and a leading cause of invasive aspergillosis in human hosts. Pandemic azole-resistant strains have emerged on a global scale, which are thought to be propagated through use of azole-based fungicides in agriculture. To perform epidemiologic studies, genetic typing of large cohorts is key. Here, I evaluate the usefulness of the frequently used csp1 marker for resistance detection and epidemiologic stratification among A. fumigatus isolates. The phylogenetic distribution of csp1 types mostly correlates with A. fumigatus population structure and is also meaningful for narrowly defined cases of azole resistance phenotypes. Nevertheless, outcrossing of csp1 into other clades is also observed. The csp1 type alone, therefore, does not sufficiently discriminate genetic clades and should not be used as the sole marker in epidemiologic studies.


Subject(s)
Aspergillus fumigatus/drug effects , Aspergillus fumigatus/genetics , Drug Resistance, Fungal/genetics , Fungal Proteins/genetics , Membrane Proteins/genetics , Antifungal Agents/pharmacology , Aspergillosis/drug therapy , Aspergillus fumigatus/isolation & purification , Genetic Markers/genetics , Humans , Microbial Sensitivity Tests , Molecular Typing/methods , Mycological Typing Techniques/methods , Polymorphism, Single Nucleotide/genetics , Voriconazole/pharmacology
17.
Int J Mol Sci ; 22(21)2021 Nov 07.
Article in English | MEDLINE | ID: mdl-34769480

ABSTRACT

A natural recombinant myxoma virus (referred to as ha-MYXV or MYXV-Tol08/18) emerged in the Iberian hare (Lepus granatensis) and the European rabbit (Oryctolagus cuniculus) in late 2018 and mid-2020, respectively. This new virus is genetically distinct from classic myxoma virus (MYXV) strains that caused myxomatosis in rabbits until then, by acquiring an additional 2.8 Kbp insert within the m009L gene that disrupted it into ORFs m009L-a and m009L-b. To distinguish ha-MYXV from classic MYXV strains, we developed a robust qPCR multiplex technique that combines the amplification of the m000.5L/R duplicated gene, conserved in all myxoma virus strains including ha-MYXV, with the amplification of two other genes targeted by the real-time PCR systems designed during this study, specific either for classic MYXV or ha-MYXV strains. The first system targets the boundaries between ORFs m009L-a and m009L-b, only contiguous in classic strains, while the second amplifies a fragment within gene m060L, only present in recombinant MYXV strains. All amplification reactions were validated and normalized by a fourth PCR system directed to a housekeeping gene (18S rRNA) conserved in eukaryotic organisms, including hares and rabbits. The multiplex PCR (mPCR) technique described here was optimized for Taqman® and Evagreen® systems allowing the detection of as few as nine copies of viral DNA in the sample with an efficiency > 93%. This real-time multiplex is the first fast method available for the differential diagnosis between classic and recombinant MYXV strains, also allowing the detection of co-infections. The system proves to be an essential and effective tool for monitoring the geographical spread of ha-MYXV in the hare and wild rabbit populations, supporting the management of both species in the field.


Subject(s)
Lagomorpha/virology , Myxoma virus , Myxomatosis, Infectious/diagnosis , Real-Time Polymerase Chain Reaction/methods , Animals , Animals, Wild , Diagnosis, Differential , Gene Transfer, Horizontal/genetics , Molecular Typing/methods , Molecular Typing/veterinary , Myxoma virus/classification , Myxoma virus/genetics , Myxomatosis, Infectious/virology , Rabbits , Real-Time Polymerase Chain Reaction/veterinary , Reproducibility of Results , Sensitivity and Specificity , Spain
18.
Mol Biol Rep ; 48(12): 7697-7702, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34665397

ABSTRACT

BACKGROUND: Human metapneumovirus (hMPV) is one of the important pathogens in infant respiratory tract infection. However, the molecular epidemiology of hMPV among children < 14 years of age hospitalized with severe acute respiratory infection (SARI) is unclear. We investigated the hMPV infection status and genotypes of children hospitalized with SARI from January 2016 to December 2020 in Huzhou, China. METHODS: A nasopharyngeal flocked swab, nasal wash, or nasopharyngeal swab/or opharyngeal swab combination sample was collected from children with SARI in Huzhou from January 2016 to December 2020. Quantitative reverse transcription-polymerase chain reaction was performed to detect hMPV RNA. The hMPV F gene was amplified and sequenced, followed by analysis using MEGA software (ver. 7.0). Epidemiological data were analyzed using Microsoft Excel 2010 and SPSS (ver. 22.0) software. RESULTS: A total of 1133 children with SARI were recruited from 2016 to 2020. Among them, 56 (4.94%) were positive for hMPV-RNA. Children < 5 years of age accounted for 85.71% of the positive cases. The hMPV incidence was high in spring and winter, especially in December and January to March. Phylogenetic analysis of the F-gene sequences of 28 hMPV strains showed that the A1, B1, and B2 genotypes were prevalent in Huzhou, and the dominant hMPV genotype varied according to surveillance year. CONCLUSIONS: HMPV is an important respiratory pathogen in children in Huzhou, with a high incidence in winter and spring in children < 5 years of age. In this study, genotypes A1, B1, and B2 were the most prevalent.


Subject(s)
Metapneumovirus/genetics , Respiratory Tract Infections/epidemiology , Respiratory Tract Infections/genetics , Base Sequence/genetics , Child , Child, Preschool , China/epidemiology , Female , Genotype , Hospitalization/trends , Humans , Infant , Male , Metapneumovirus/classification , Metapneumovirus/pathogenicity , Molecular Epidemiology/methods , Molecular Typing/methods , Paramyxoviridae Infections/epidemiology , Paramyxoviridae Infections/genetics , Paramyxoviridae Infections/virology , Phylogeny , Respiratory Tract Infections/metabolism , Sequence Analysis, DNA/methods
19.
J Microbiol Methods ; 191: 106348, 2021 12.
Article in English | MEDLINE | ID: mdl-34699864

ABSTRACT

Neonothopanus gardneri, also known as coconut flower mushroom (flor-de-coco), is a Brazilian bioluminescent basidiomycete found in Palm Forest, a transitional biome between the Amazonian Forest and Caatinga (Savanna-like vegetation) in Northeast Brazil, especially in Piauí State. Recent advances toward the elucidation of fungal bioluminescence have contributed to the discovery of four genes (hisps, h3h, luz and cph) involved with the bioluminescence process, the so-called Caffeic Acid Cycle (CAC) and to develop biotechnological applications such autoluminescent tobacco plants and luciferase-based reporter genes. High-yield and -quality RNA-extraction methods are required for most of these purposes. Herein, four methods for RNA isolation from the mycelium of N. gardneri were evaluated: RNeasy® kit (QIAGEN), TRI+, TRI18G+, and TRI26G+. Highest RNA yield was observed for TRI18G+ and TRI26G+ methods, an increase of ~130% in comparison to the RNeasy® method and of ~40% to the TRI+ protocol. All the RNA samples showed good purity and integrity, except by gDNA contamination in RNA samples produced with the RNeasy® method. High quality of RNA samples was confirmed by successful cDNA synthesis and PCR amplification of the coding sequence of h3h gene, responsible for the hydroxylation of the precursor of fungal luciferin (3-hydroxyhispidin). Similarly, RT-qPCR amplification of ef-tu gene, related to the protein biosynthesis in the cell, was demonstrated from RNA samples. This is the first report of a reproducible, time-saving and low-cost optimized method for isolation of high-quality and -yield, DNA-free RNA from a bioluminescent fungus, but that can also be useful for other basidiomycetes.


Subject(s)
Agaricales/genetics , Luminescent Measurements/methods , Mycelium/genetics , Mycological Typing Techniques/methods , RNA, Fungal/isolation & purification , Agaricales/isolation & purification , Agaricales/metabolism , Biotechnology , Brazil , DNA, Complementary , Ecosystem , Forests , Luciferins , Molecular Typing/methods , Polymerase Chain Reaction , Protein Biosynthesis
20.
Nat Commun ; 12(1): 4188, 2021 07 07.
Article in English | MEDLINE | ID: mdl-34234121

ABSTRACT

Klebsiella pneumoniae is a leading cause of antimicrobial-resistant (AMR) healthcare-associated infections, neonatal sepsis and community-acquired liver abscess, and is associated with chronic intestinal diseases. Its diversity and complex population structure pose challenges for analysis and interpretation of K. pneumoniae genome data. Here we introduce Kleborate, a tool for analysing genomes of K. pneumoniae and its associated species complex, which consolidates interrogation of key features of proven clinical importance. Kleborate provides a framework to support genomic surveillance and epidemiology in research, clinical and public health settings. To demonstrate its utility we apply Kleborate to analyse publicly available Klebsiella genomes, including clinical isolates from a pan-European study of carbapenemase-producing Klebsiella, highlighting global trends in AMR and virulence as examples of what could be achieved by applying this genomic framework within more systematic genomic surveillance efforts. We also demonstrate the application of Kleborate to detect and type K. pneumoniae from gut metagenomes.


Subject(s)
Bacterial Proteins/genetics , Cross Infection/microbiology , Klebsiella Infections/microbiology , Klebsiella pneumoniae/genetics , Molecular Typing/methods , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Cross Infection/diagnosis , Cross Infection/drug therapy , Cross Infection/epidemiology , Datasets as Topic , Drug Resistance, Multiple, Bacterial/genetics , Epidemiological Monitoring , Gastrointestinal Microbiome/genetics , Genome, Bacterial , Humans , Infant , Infant, Newborn , Klebsiella Infections/diagnosis , Klebsiella Infections/drug therapy , Klebsiella Infections/epidemiology , Klebsiella pneumoniae/isolation & purification , Klebsiella pneumoniae/pathogenicity , Metagenome/genetics , Molecular Epidemiology/methods , Mutation , Phylogeny , Software , Virulence/genetics , Virulence Factors/genetics , Whole Genome Sequencing , beta-Lactamases/genetics
SELECTION OF CITATIONS
SEARCH DETAIL
...