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1.
Pathogens ; 11(10)2022 Oct 05.
Article in English | MEDLINE | ID: mdl-36297206

ABSTRACT

BACKGROUND: Pets are increasingly becoming part of the family and interactions between pets and their owners is changing. This results in extended and more intimate contact between owners and their pets, which give rise to zoonotic risks. OBJECTIVE: To establish the presence of potential zoonotic pathogens in pets that sleep with their owner. METHODS: As a pilot study, a group of 28 healthy dogs and 22 healthy cats were monitored for the presence of the zoonotic parasites Cheyletiella, Ctenocephalides spp. and Toxocara spp., the dermatophyte Microsporum canis, and the bacteria Clostridium difficile, Salmonella spp., Campylobacter jejuni and Enterobacteriaceae. This was investigated by taking samples from the fur, the footpads and the animal bed. The owners filled in a questionnaire. RESULTS: In total, 29 of the 50 pets (58%) slept on the bed, of which 15 pets (30%) slept in the bed (under the blankets). A total of 19/22 dogs (86%) and 7/22 cats (32%) tested positive for Enterobacteriaceae on the fur or footpads. Fleas were found in 5/22 of the cats' (23%) and 2/28 of the dogs' (7%) favourite sleeping spots. High levels of aerobic colonies were found, up to 216 colony forming units/cm2. Other pathogens were not found in this study. CONCLUSIONS: The results of this preliminary study confirm literature reports that pets may constitute a potential risk in the transmission of zoonotic pathogens to their owner, especially during direct contact when sleeping in the same bed. Owners should therefore be informed about these risks and educated to interact with their pets in a more responsible way.

2.
Antibiotics (Basel) ; 10(7)2021 Jul 14.
Article in English | MEDLINE | ID: mdl-34356775

ABSTRACT

Staphylococcus pseudintermedius is an important pathogen in dogs that occasionally causes infections in humans as an opportunistic pathogen of elderly and immunocompromised people. This study compared the genomic relatedness and antimicrobial resistance genes using genome-wide association study (GWAS) to examine host association of canine and human S. pseudintermedius isolates. Canine (n = 25) and human (n = 32) methicillin-susceptible S. pseudintermedius (MSSP) isolates showed a high level of genetic diversity with an overrepresentation of clonal complex CC241 in human isolates. This clonal complex was associated with carriage of a plasmid containing a bacteriocin with cytotoxic properties, a CRISPR-cas domain and a pRE25-like mobile element containing five antimicrobial resistance genes. Multi-drug resistance (MDR) was predicted in 13 (41%) of human isolates and 14 (56%) of canine isolates. CC241 represented 54% of predicted MDR isolates from humans and 21% of predicted MDR canine isolates. While it had previously been suggested that certain host-specific genes were present the current GWAS analysis did not identify any genes that were significantly associated with human or canine isolates. In conclusion, this is the first genomic study showing that MSSP is genetically diverse in both hosts and that multidrug resistance is important in dog and human-associated S. pseudintermedius isolates.

3.
BMJ Case Rep ; 13(12)2020 Dec 13.
Article in English | MEDLINE | ID: mdl-33318266

ABSTRACT

In this case, we present an uncommon gastrointestinal infection in an immunocompromised patient that was solely diagnosed because of close collaboration between treating physicians and microbiologists. The patient is a 42-year-old male who underwent heart transplantation 5 years earlier. He presented with fever, weight loss, diarrhoea and tiredness. Initial investigations could not elucidate the aetiology of his symptoms. The patient was referred to the department of infectious diseases for further evaluation. Serology for Yersinia species was ordered and the result was suggestive for the possibility of a Yersinia species infection. Close collaboration between treating physicians and microbiologists followed and led to additional investigations, which revealed the diagnosis of a Yersinia pseudotuberculosis infection with extensive lesions in the gastrointestinal tract. Treatment with ciprofloxacin resulted in complete resolution of symptoms and healing of the gastrointestinal lesions. In conclusion, this case underlines the need for a multidisciplinary approach to complex patients of which symptoms have yet to be understood.


Subject(s)
Heart Transplantation , Ileitis/diagnosis , Immunocompromised Host , Ulcer/diagnosis , Yersinia pseudotuberculosis Infections/diagnosis , Adult , Anti-Bacterial Agents/therapeutic use , Ciprofloxacin/therapeutic use , Humans , Ileitis/drug therapy , Ileitis/microbiology , Ileocecal Valve/microbiology , Male , Ulcer/drug therapy , Ulcer/microbiology , Yersinia pseudotuberculosis Infections/drug therapy
4.
Int J Antimicrob Agents ; 55(4): 105911, 2020 Apr.
Article in English | MEDLINE | ID: mdl-31991219

ABSTRACT

Mycoplasma genitalium is a sexually transmitted urogenital pathogen, and infection can result in serious symptoms. As M. genitalium is rather difficult to culture, infections are usually detected by molecular methods. Unfortunately, there has recently been a significant increase in resistance to azithromycin and moxifloxacin used for the treatment of M. genitalium infections. The increased resistance to (often empirically prescribed) M. genitalium treatments has resulted in frequent therapy failures and stresses the need for routine detection of antimicrobial resistance. In M. genitalium, antimicrobial resistance is almost always the result of DNA mutations and thus can easily be detected by molecular techniques. Regrettably, many microbiology laboratories do not use molecular techniques for the detection of bacterial antimicrobial resistance. As molecular tests are becoming available for M. genitalium, both for the establishment of infection and the detection of antimicrobial resistance, it is now more important to ensure that knowledge on the resistance mechanisms is transferred from the laboratory to the clinician. This review will provide a brief summary of the current status of antimicrobial resistance, its molecular mechanisms and the impact on the current status of M. genitalium treatment.


Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial/genetics , Mycoplasma Infections/drug therapy , Mycoplasma genitalium/drug effects , Mycoplasma genitalium/genetics , Azithromycin/therapeutic use , Doxycycline/therapeutic use , Female , Female Urogenital Diseases/drug therapy , Female Urogenital Diseases/microbiology , Humans , Male , Male Urogenital Diseases/drug therapy , Male Urogenital Diseases/microbiology , Microbial Sensitivity Tests , Moxifloxacin/therapeutic use , Mycoplasma Infections/microbiology , Polymorphism, Single Nucleotide/genetics , Sexually Transmitted Diseases, Bacterial/drug therapy
5.
Diagn Microbiol Infect Dis ; 95(3): 114858, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31358343

ABSTRACT

Seven weeks after being kicked in the face by a cow, a 34-year-old male patient developed a posttraumatic mycobacterial lymphadenitis. A rapidly growing mycobacterial isolate cultured from a surgically drained lymphadenitis pus specimen was identified as Mycobacterium smegmatis by matrix-assisted laser desorption/ionization mass spectrometry and a combination of ITS-, hsp65-, and 16S rRNA-DNA sequence analysis, but as Mycobacterium fortuitum complex using the commercial INNO-LiPA Mycobacteria v2 line probe assay. As it is unclear if the misidentification of this strain is an exception, more research is required.


Subject(s)
Lymphadenitis/diagnosis , Molecular Diagnostic Techniques/methods , Mycobacterium Infections, Nontuberculous/diagnosis , Mycobacterium fortuitum/classification , Mycobacterium fortuitum/genetics , Mycobacterium smegmatis/classification , Mycobacterium smegmatis/genetics , Adult , Animals , Cattle , Diagnostic Errors , Humans , Lymphadenitis/microbiology , Lymphadenitis/pathology , Lymphadenitis/therapy , Male , Microbial Sensitivity Tests , Molecular Diagnostic Techniques/standards , Mycobacterium Infections, Nontuberculous/microbiology , Mycobacterium Infections, Nontuberculous/pathology , Mycobacterium Infections, Nontuberculous/surgery , Mycobacterium fortuitum/chemistry , Mycobacterium smegmatis/chemistry , Reagent Kits, Diagnostic , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Treatment Outcome
6.
Parasitology ; 146(9): 1131-1139, 2019 08.
Article in English | MEDLINE | ID: mdl-30165915

ABSTRACT

Dientamoeba fragilis (D. fragilis) is an intestinal parasite frequently detected in humans with abdominal pain and diarrhoea, but it is also commonly found in asymptomatic subjects. Hence its clinical relevance is often disputed. The introduction of polymerase chain reaction (PCR) is a versatile and sensitive diagnostic technique for the detection of intestinal parasites, and in some Western world countries PCR has almost completely replaced microscopic diagnostics. PCR has however resulted in an increase in the number of D. fragilis-positive patients. The disputed pathogenic nature of this intestinal parasite and an apparent increase in the incidence of patients with positive PCR results have renewed the discussions between clinicians and microbiologists on how to deal with an infected patient. Moreover, treatment guidelines differ throughout the world which makes it difficult for clinicians to choose an optimal therapeutic regimen.AimTo summarize and discuss the current knowledge on the pathogenicity, best diagnostic approach, treatment and follow-up of children and adults infected with D. fragilis.


Subject(s)
Dientamoeba/pathogenicity , Dientamoebiasis/diagnosis , Dientamoebiasis/drug therapy , Practice Guidelines as Topic , Adult , Animals , Antiprotozoal Agents/therapeutic use , Child , Diarrhea/parasitology , Dientamoeba/genetics , Dientamoebiasis/parasitology , Feces/parasitology , Humans
7.
Eur J Clin Microbiol Infect Dis ; 37(11): 2137-2144, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30276584

ABSTRACT

Patients infected by Mycoplasma genitalium are often treated empirically with the macrolide azithromycin. Macrolide resistance is becoming quite common; empirical treatment is compromised. Sequencing was initially used to detected azithromycin resistance-associated mutations. As this was laborious, qPCRs have been developed for their detection. In the present study, we describe a fast, sensitive, and specific qPCR assay that enables routine testing of M. genitalium and macrolide resistance-associated mutations in a single assay. M. genitalium positive clinical samples were used to compare (i) the commonly used MgPa assay for the detection of M. genitalium infections (MgPa qPCR), (ii) a combined 23S rRNA gene PCR/sequencing assay (Mg23S qPCR/Sequencing) to identify macrolide resistance-associated mutations, and (iii) our newly developed probe-based melt curve qPCR for simultaneous detection of M. genitalium and macrolide resistance-associated mutations (Macrolide-R/MG ELITe MGB Kit, Elitech Bothel USA in short Mg MacrolideR qPCR). Specificity of the qPCR was tested using urogenital samples that were tested positive for a range of other micro-organisms. M. genitalium was detected in 196/236 (83.1%) samples by the MgPa qPCR, versus 172/236 (72.9%) by the combined Mg23S qPCR/Sequencing, and 202/236 (85.6%) by the Mg MacrolideR qPCR. The Mg MacrolideR qPCR showed high concordance to the Mg23S qPCR/Sequencing assay (201 vs 202 could be genotyped, respectively) for the detection of the macrolide resistant mutations. None of the other urogenital pathogens were tested positive in the Mg MacrolideR qPCR, indicating specificity. The Mg MacrolideR qPCR is fast, sensitive, specific, and can easily be implemented in the routine diagnostics.


Subject(s)
Antitubercular Agents/pharmacology , Drug Resistance, Bacterial , Macrolides/pharmacology , Mycoplasma Infections/diagnosis , Mycoplasma Infections/microbiology , Mycoplasma genitalium/drug effects , Mycoplasma genitalium/genetics , Adolescent , Adult , Antitubercular Agents/therapeutic use , Female , Humans , Macrolides/therapeutic use , Male , Middle Aged , Mutation , Mycoplasma Infections/drug therapy , RNA, Ribosomal, 23S/genetics , Real-Time Polymerase Chain Reaction , Sensitivity and Specificity , Young Adult
9.
Front Immunol ; 9: 1375, 2018.
Article in English | MEDLINE | ID: mdl-29967615

ABSTRACT

Metaplasia in Barrett's esophagus (BE) is characterized by the transition of squamous epithelium into intestinal-type columnar epithelium. The immune response in BE shares many similarities with the response found in the gut, which is different from the response found in a normal-looking esophagus. Here, we investigated the role of the genes associated with the retinoic acid (RA) pathway in BE, as RA is important not only in shaping the gut's immune response but also in the induction of metaplasia in vitro. mRNA was isolated from esophageal and duodenal biopsies from BE (n = 14), reflux esophagitis patients (n = 9), and controls (n = 12). cDNA was made and qPCR was performed. The expression of RALDH1, CYP26A1, MAdCAM1 were similar for both the BE and duodenum, but different when compared to squamous esophageal epithelium. BE was characterized by a higher expression of RALDH2 and FOXP3, compared to the duodenum. In BE, RALDH2 correlated with expression of the myeloid dendritic cell-specific genes: CD11c and CD1c. Also, RALDH2 expression correlated with RAR-ß and FOXP3. Hierarchical clustering on the expression of multiple relevant genes demonstrated that BE, duodenum, and SQ tissues are clustered as three different groups. The differential expression of RA-specific genes and dendritic cell (DC)-subsets indicates that BE resembles duodenal tissue. The higher expression of RALDH2 and FOXP3 in BE points at a mechanism associated with a possible anti-inflammatory microenvironment. This aberrant immune regulation might contribute to the altered tissue and immune responses found in BE.

10.
Enferm. infecc. microbiol. clín. (Ed. impr.) ; 36(3): 169-171, mar. 2018. tab
Article in English | IBECS | ID: ibc-171412

ABSTRACT

Introduction: The aim of this study was to determine the prevalence of Mycoplasma genitalium infection and the resistance to macrolides within a general population in Madrid in 2015. Methods: We collected 359 urine samples from a general population with symptoms of sexually transmitted infections (STIs). All samples underwent a real-time PCR. For the detection of macrolide resistance, a 283bp fragment of region V of the 23S rRNA gene of M. genitaliumwas amplified and sequenced. Results: We found a prevalence of 3.34% of M. genitalium and a macrolide resistance rate of 20%. In males, the prevalence was 6.62% and in women 0.96%, being significantly higher in males. Conclusions: The prevalence obtained shows that it is a pathogen to consider in our environment. These findings stress the need for routine testing of M. genitalium infections and would seem to suggest the advisability of resistance testing (AU)


Introducción: El objetivo de este estudio fue determinar en 2015 en una población general de Madrid la prevalencia de infección por Mycoplasma genitalium (M. genitalium) y la resistencia a macrólidos. Métodos: Se recogieron 359 muestras de orina procedentes de una población general con síntomas de infección de transmisión sexual. A todas las muestras se les realizó una PCR a tiempo real. Para la detección de resistencias a macrólidos, se amplificó y secuenció un fragmento de 283 pb de la región V del gen 23S rRNA de M. genitalium. Resultados: Se encontró una prevalencia de un 3,34% de M. genitalium y un 20% de resistencia a macrólidos. En varones la prevalencia fue del 6,62% y en mujeres del 0,96%, siendo significativamente superior en varones. Conclusión: La prevalencia obtenida muestra que es un patógeno a considerar en nuestro entorno. Estos hallazgos hacen hincapié en la necesidad de realizar pruebas de rutina de infección por M. genitalium y argumentan que es recomendable realizar pruebas de resistencia (AU)


Subject(s)
Humans , Female , Mycoplasma genitalium/isolation & purification , Reproductive Tract Infections/drug therapy , Reproductive Tract Infections/epidemiology , Macrolides/therapeutic use , Drug Resistance, Microbial , Urinalysis/methods , Urine Specimen Collection/methods
11.
Enferm Infecc Microbiol Clin (Engl Ed) ; 36(3): 169-171, 2018 Mar.
Article in English, Spanish | MEDLINE | ID: mdl-28291669

ABSTRACT

INTRODUCTION: The aim of this study was to determine the prevalence of Mycoplasma genitalium infection and the resistance to macrolides within a general population in Madrid in 2015. METHODS: We collected 359 urine samples from a general population with symptoms of sexually transmitted infections (STIs). All samples underwent a real-time PCR. For the detection of macrolide resistance, a 283bp fragment of region V of the 23S rRNA gene of M. genitalium was amplified and sequenced. RESULTS: We found a prevalence of 3.34% of M. genitalium and a macrolide resistance rate of 20%. In males, the prevalence was 6.62% and in women 0.96%, being significantly higher in males. CONCLUSIONS: The prevalence obtained shows that it is a pathogen to consider in our environment. These findings stress the need for routine testing of M. genitalium infections and would seem to suggest the advisability of resistance testing.


Subject(s)
Anti-Bacterial Agents/pharmacology , Genital Diseases, Female/epidemiology , Genital Diseases, Female/microbiology , Genital Diseases, Male/epidemiology , Genital Diseases, Male/microbiology , Macrolides/pharmacology , Mycoplasma Infections/epidemiology , Mycoplasma Infections/microbiology , Mycoplasma genitalium/drug effects , Adult , Anti-Bacterial Agents/therapeutic use , Drug Resistance, Bacterial , Female , Genital Diseases, Female/drug therapy , Genital Diseases, Male/drug therapy , Humans , Macrolides/therapeutic use , Male , Mycoplasma Infections/drug therapy , Prevalence , Young Adult
12.
Clin Microbiol Rev ; 30(2): 529-555, 2017 04.
Article in English | MEDLINE | ID: mdl-28298472

ABSTRACT

Whipple's disease is a rare infectious disease that can be fatal if left untreated. The disease is caused by infection with Tropheryma whipplei, a bacterium that may be more common than was initially assumed. Most patients present with nonspecific symptoms, and as routine cultivation of the bacterium is not feasible, it is difficult to diagnose this infection. On the other hand, due to the generic symptoms, infection with this bacterium is actually quite often in the differential diagnosis. The gold standard for diagnosis used to be periodic acid-Schiff (PAS) staining of duodenal biopsy specimens, but PAS staining has a poor specificity and sensitivity. The development of molecular techniques has resulted in more convenient methods for detecting T. whipplei infections, and this has greatly improved the diagnosis of this often missed infection. In addition, the molecular detection of T. whipplei has resulted in an increase in knowledge about its pathogenicity, and this review gives an overview of the new insights in epidemiology, pathogenesis, clinical manifestations, diagnosis, and treatment of Tropheryma whipplei infections.


Subject(s)
Whipple Disease , Anti-Bacterial Agents , Humans , Tropheryma/physiology , Whipple Disease/diagnosis , Whipple Disease/epidemiology , Whipple Disease/pathology , Whipple Disease/therapy
14.
BMC Gastroenterol ; 16(1): 94, 2016 Aug 12.
Article in English | MEDLINE | ID: mdl-27520775

ABSTRACT

BACKGROUND: Infection with Helicobacter pylori is associated with severe digestive diseases including chronic gastritis, peptic ulcer disease, and gastric cancer. Successful eradication of this common gastric pathogen in individual patients is known to prevent the occurrence of peptic ulcer disease and gastric cancer. DISCUSSION: With half of the world's population being infected with H, pylori and only few antibiotics result in an effective eradication, a successful antibiotic driven worldwide eradication program seems unlikely. In addition, H. pylori eradication is not always beneficial as it has been described that eradication can be associated with an increased frequency of other disorders such as pediatric asthma, inflammatory bowel diseases and Barrett's Esophagus. We have to accept that eradication of this infection is a two-edged sword that is both useful and harmful and we should therefore focus our H. pylori eradication policy toward selectively identify and destroy only the virulent strains. CONCLUSION: In order to still be able to effectively treat H. pylori infections in the future we need an alternative diagnostic/treatment algorithm. This would involve a shift towards more precise and enhanced disease predicting diagnosis that tries to identify patients with chance of developing severe diseases such as gastric cancer, rather than the current regime that is geared towards find and destroy all H. pylori.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Gastritis/drug therapy , Helicobacter Infections/drug therapy , Helicobacter pylori , Drug Resistance, Bacterial , Duodenal Ulcer/microbiology , Gastritis/diagnosis , Gastritis/microbiology , Helicobacter Infections/complications , Helicobacter Infections/diagnosis , Helicobacter pylori/drug effects , Humans , Stomach Neoplasms/microbiology , Stomach Ulcer/microbiology
15.
J Gastroenterol Hepatol ; 31(11): 1808-1815, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27061336

ABSTRACT

The implementation of polymerase chain reaction (PCR)-based diagnostics of intestinal protozoa has led to higher sensitivity and (subtype) specificity, more convenient sampling, and the possibility for high-throughput screening. PCR for routine detection of human intestinal protozoa in fecal samples is used by an increasing number of clinical laboratories. This paper discusses the recent developments in the diagnosis of intestinal protozoa, with an emphasis on PCR-based diagnostics. Although many reviews have described the technical aspects of PCR-based diagnostics, this review focuses on the clinical consequences that result from the shift from microscopic toward PCR-based diagnostics. Despite its undisputed superiority, the use of PCR comes with challenges that clinicians should be aware of.


Subject(s)
Intestinal Diseases, Parasitic/diagnosis , Protozoan Infections/diagnosis , Humans , Intestinal Diseases, Parasitic/epidemiology , Point-of-Care Systems , Polymerase Chain Reaction/methods , Prevalence , Protozoan Infections/epidemiology , Sensitivity and Specificity
16.
BMC Infect Dis ; 16: 39, 2016 Jan 30.
Article in English | MEDLINE | ID: mdl-26830915

ABSTRACT

BACKGROUND: Infectious intestinal disease (IID) is an important cause of morbidity in developed countries and a frequent reason for general practitioner (GP) consultation. In recent years polymerase chain reaction (PCR) based techniques have gradually replaced conventional enteropathogen detection techniques like microscopy and culture in primary care patients suspected of IID. PCR features testing of multiple enteropathogens in a single faecal sample with shorter turnaround times and greater sensitivity compared to conventional techniques. However, the associated costs and benefits have not been quantified. Furthermore, primary care incidence and prevalence estimates of enteropathogens associated with IID are sparsely available and predominantly based on conventional techniques. The PROUD-study (PCR diagnostics in Outpatients with Diarrhoea) determines: 1) health (care) effects and 2) cost-effectiveness of PCR introduction in primary care patients suspected of IID; 3) occurrence of major enteropathogens in primary care patients suspected of IID. METHODS: A before-after cohort study will be performed of patients with suspected IID consulting a GP in the Utrecht General Practitioner Network (UGPN), covering the before period (2010-2011) with conventional testing and the after period (2013-2014) with PCR testing. Prospective study data on patient characteristics and primary outcome measures (i.e. healthcare use and disease outcome) will be collected from electronic patient and laboratory records in 2015 and 2016. The effect of PCR introduction is investigated by comparing the primary outcome measures and their associated healthcare costs between the conventional period and the PCR period, and is followed by a cost-effectiveness analysis. To determine the occurrence of enteropathogens associated with IID in primary care, routine care faeces samples from the year 2014 will be screened using PCR. DISCUSSION: The PROUD-study will quantify the costs and effects of the introduction of PCR techniques for enteropathogens in primary care patients suspected of IID and generate up-to-date and sensitive estimates of enteropathogen occurrence among primary care patients.


Subject(s)
Diarrhea/diagnosis , Feces/microbiology , Research Design , Bacteria/genetics , Bacteria/isolation & purification , Cohort Studies , Databases, Factual , Diarrhea/microbiology , Diarrhea/virology , Feces/virology , Gastroenteritis/epidemiology , Gastroenteritis/microbiology , Gastroenteritis/virology , Health Care Costs , Humans , Intestinal Diseases/microbiology , Intestinal Diseases/virology , Norovirus/genetics , Norovirus/isolation & purification , Outpatients , Polymerase Chain Reaction , Prospective Studies , Rotavirus/genetics , Rotavirus/isolation & purification
18.
J Clin Microbiol ; 54(4): 1130-2, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26763972

ABSTRACT

Identification ofNeisseria gonorrhoeaeby the Bruker matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) system may be affected by "B consistency categorization." A supplementary database of 17N. gonorrhoeaemain spectra was constructed. Twelve of 64N. gonorrhoeaeidentifications were categorized with B consistency, which disappeared using the supplementary database. Database extension did not result in misidentification ofNeisseria meningitidis.


Subject(s)
Computational Biology/methods , Databases as Topic , Neisseria gonorrhoeae/isolation & purification , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Female , Humans , Male , Neisseria gonorrhoeae/chemistry
19.
J Clin Microbiol ; 53(9): 2877-88, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26135867

ABSTRACT

Whole-genome sequencing is becoming a leading technology in the typing and epidemiology of microbial pathogens, but the increase in genomic information necessitates significant investment in bioinformatic resources and expertise, and currently used methodologies struggle with genetically heterogeneous bacteria such as the human gastric pathogen Helicobacter pylori. Here we demonstrate that the alignment-free analysis method feature frequency profiling (FFP) can be used to rapidly construct phylogenetic trees of draft bacterial genome sequences on a standard desktop computer and that coupling with in silico genotyping methods gives useful information for comparative and clinical genomic and molecular epidemiology applications. FFP-based phylogenetic trees of seven gastric Helicobacter species matched those obtained by analysis of 16S rRNA genes and ribosomal proteins, and FFP- and core genome single nucleotide polymorphism-based analysis of 63 H. pylori genomes again showed comparable phylogenetic clustering, consistent with genomotypes assigned by using multilocus sequence typing (MLST). Analysis of 377 H. pylori genomes highlighted the conservation of genomotypes and linkage with phylogeographic characteristics and predicted the presence of an incomplete or nonfunctional cag pathogenicity island in 18/276 genomes. In silico analysis of antibiotic susceptibility markers suggests that most H. pylori hspAmerind and hspEAsia isolates are predicted to carry the T2812C mutation potentially conferring low-level clarithromycin resistance, while levels of metronidazole resistance were similar in all multilocus sequence types. In conclusion, the use of FFP phylogenetic clustering and in silico genotyping allows determination of genome evolution and phylogeographic clustering and can contribute to clinical microbiology by genomotyping for outbreak management and the prediction of pathogenic potential and antibiotic susceptibility.


Subject(s)
Drug Resistance, Bacterial , Genetic Variation , Genotyping Techniques/methods , Helicobacter pylori/classification , Helicobacter pylori/genetics , Molecular Typing/methods , Virulence Factors/genetics , Anti-Bacterial Agents/pharmacology , Cluster Analysis , Genes, Bacterial , Genome, Bacterial , Humans , Molecular Epidemiology/methods , Phylogeny , Sequence Analysis, DNA/methods
20.
Exp Mol Pathol ; 98(3): 390-2, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25779023

ABSTRACT

The presence of Pneumocystis jirovecii in fresh clinical materials can be detected by PCR with high sensitivity and is thus preferred over microscopic methods. However, fresh materials are not always available, and on formalin-fixed paraffin-embedded materials, PCR may result in reduced detection rates. In this study the diagnostic sensitivity of P. jirovecii real time PCR on DNA isolated from fresh bronchoalveolar lavage (BAL) samples versus that from matched FFPE derived DNA is analyzed. Our results indicate that when targeting a small DNA fragment P. jirovecii PCR can be performed on FFPE BAL samples with acceptable sensitivity (up to 83.3%). This is considerably higher than the 33.3% positives observed by classical staining of these samples.


Subject(s)
Bronchoalveolar Lavage Fluid/microbiology , DNA, Bacterial/genetics , Pneumocystis carinii/isolation & purification , Real-Time Polymerase Chain Reaction/methods , DNA, Bacterial/isolation & purification , Formaldehyde/chemistry , Humans , Paraffin Embedding , Pneumocystis carinii/genetics , Sensitivity and Specificity , Tissue Fixation
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