PCR analysis and specific immunohistochemistry revealing a high prevalence of non-Helicobacter pylori Helicobacters in Helicobacter pylori-negative gastric disease patients in Japan: High susceptibility to an Hp eradication regimen.

BACKGROUND: The clinical significance of non-Helicobacter pylori Helicobacter (NHPH) is still unknown. There are many reports of NHPH-infected patients suffering from gastric diseases. Here, we investigated the polymerase chain reaction (PCR) positivity of NHPH infection in gastric disease patients who were negative for H. pylori (Hp) by the rapid urease test and by pathological observation. MATERIALS AND METHODS: We collected the 296 endoscopically obtained gastric mucosal samples of Hp-negative gastric disease patients diagnosed based on a rapid urease test and pathology from 17 hospitals in Japan from September 2013 to June 2019, and we analyzed the existence of Hp and NHPH by PCR. The samples were also treated by indirect immunohistochemistry using an anti-Helicobacter suis VacA paralog antibody and were observed by confocal laser microscopy. RESULTS: Among the 236 non-Hp-eradicated cases, 49 cases (20.8%) were positive for NHPH. Among them, 20 cases were positive for Helicobacter suis, 7 cases were positive for Helicobacter heilmannii sensu stricto/ Helicobacter ailurogastricus (Hhss/Ha), and the other 22 cases could not be identified. The regional differences in the infection rates were significant. Forty percent of the nodular gastritis cases, 24% of the MALT lymphoma, 17% of the chronic gastritis cases, and 33% of the gastroduodenal ulcer cases were NHPH positive. Forty-five patients had been treated with one of the four types of combinations of a proton pump inhibitor and two antibiotics, and in all of these cases, the NHPH diagnosed by PCR was successfully eradicated. Immunohistochemistry using the Helicobacter suis-specific HsvA antibody coincided well with the PCR results. Among the 29 post-Hp eradication cases, three were NHPH positive, including one Hhss/Ha-positive case. Thus, approx. 20% of the Hp-negative non-Hp-eradicated gastric disease patients treated at 17 hospitals in Japan were infected with NHPH.

Increased Expression of 15-Hydroxyprostaglandin Dehydrogenase in Spinal Astrocytes During Disease Progression in a Model of Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is an adult-onset, progressive, and fatal neurodegenerative disease caused by selective loss of motor neurons. Both ALS model mice and patients with sporadic ALS have increased levels of prostaglandin E2 (PGE2). Furthermore, the protein levels of microsomal PGE synthase-1 and cyclooxygenase-2, which catalyze PGE2 biosynthesis, are significantly increased in the spinal cord of ALS model mice. However, it is unclear whether PGE2 metabolism in the spinal cord is altered. In the present study, we investigated the protein level of 15-hydroxyprostaglandin dehydrogenase (15-PGDH), a key enzyme in prostaglandin metabolism, in ALS model mice at three different disease stages. Western blotting revealed that the 15-PGDH level was significantly increased in the lumbar spinal cord at the symptomatic stage and end stage. Immunohistochemical staining demonstrated that 15-PGDH immunoreactivity was localized in glial fibrillary acidic protein (GFAP)-positive astrocytes at the end stage. In contrast, 15-PGDH immunoreactivity was not identified in NeuN-positive large cells showing the typical morphology of motor neurons in the anterior horn. Unlike 15-PGDH, the level of PGE2 in the spinal cord was increased only at the end stage. These results suggest that the significant increase of PGE2 at the end stage of ALS in this mouse model is attributable to an imbalance of the synthetic pathway and 15-PGDH-dependent scavenging system for PGE2, and that this drives the pathogenetic mechanism responsible for transition from the symptomatic stage.

In the Aftermath of Helicobacter pylori: Other Helicobacters Rising Up to Become the Next Gastric Epidemic?

Non-Helicobacter pylori-Helicobacters including H. suis, H. heilmanniisensu stricto and H. felis comprise a group of bacteria that may inhabit the stomach of humans and animals. Human gastric infection has been associated with gastritis, ulcer, MALT lymphoma and cancer. Although the fastidious nature of these organisms has hampered their research, recent advancements in in vitro cultivation and recent reports on in vivo models and prevalence studies in humans suggest this group of bacteria to be of more clinical significance than earlier believed. The present review discusses their history, microbiology and relevance to human health.

Examination of Cyp51A-Mediated Azole Resistance in Aspergillus lentulus Using CRISPR/Cas9 Genome Editing.

Aspergillus lentulus was first reported in 2005 as a cryptic species of Aspergillus fumigatus, and since then, its resistance to azole drugs and the high mortality rate of infected individuals have emerged as problems. Although it has been reported that P450 14-α sterol demethylase (Cyp51) is involved in azole resistance in A. lentulus, the specific resistance mechanism has not been elucidated. In this study, we successfully introduced the entire A. fumigatus cyp51A gene into the cyp51A locus in A. lentulus using the CRISPR/Cas9 genome-editing system. The A. lentulus strains harboring A. fumigatus cyp51A showed reduced minimum inhibitory concentrations for itraconazole and voriconazole compared with those of the parent strain. This finding suggests that Cyp51A is involved in azole resistance in A. lentulus and may contribute to the elucidation of the mechanism of resistance to azole drugs via Cyp51A and to the development of new antifungal drugs. In addition, our successful application of the CRISPR/Cas9 system to A. lentulus opens the door to examination of other gene functions in this fungus.

Non-valvular Infective Endocarditis Caused by Sarocladium kiliense in an Immunocompromised Patient with Aplastic Anemia.

Sarocladium kiliense is ubiquitous in the human environment and is an emerging opportunistic pathogen, especially among immunocompromised hosts. A 77-year-old man diagnosed with aplastic anemia suffered from non-valvular endocarditis. After he passed away, fungal hyphae were observed in several lesions on a postmortem examination. Polymerase chain reaction (PCR) and a DNA sequence analysis revealed S. kiliense as the causative organism. This is the first case report of non-valvular fungal endocarditis caused by S. kiliense identified by PCR and a DNA sequence analysis in an immunocompromised patient. Although rare, invasive fungal infection caused by S. kiliense should be considered in immunocompromised hosts.

Non-Helicobacter pylori Helicobacter (NHPH) positive gastric cancer.

Genetic analysis and culturing techniques for gastric non-Helicobacter pylori Helicobacter (NHPH) are progressing. NHPH is reported to accompany nodular gastritis, gastric MALT lymphoma, and mild gastritis. However, only a few gastric cancer cases infected by NHPH have been reported. PCR analysis specific for NHPH and H. pylori was performed for DNA from gastric mucosa of 282 Korean gastric cancer patients, who were treated with endoscopic submucosal dissection. For more precise strain detection of NHPH, NHPH-positive mucosa was stained by immunohistochemistry specific for Helicobacter suis. The Cancer Genome Atlas (TCGA) classification was analyzed for these 3 gastric cancer sub-groups by in situ hybridization and immunohistochemistry. Among 281 patients, 3 patients (1.1%) were positive for NHPH. One patient (Patient 1) was also positive for H. pylori by PCR, another patient (Patient 3) was positive for serum IgG for H. pylori, and the other patient (Patient 2) had no evidence for H. pylori infection. Gastric mucosa of Patients 2 and 3 were positive for H. suis staining. All three NHPH-positive gastric cancers were located in the antrum, and belonged to the Chromosomal Instability Type of TCGA classification. Gastric NHPH can be a cause of gastric cancer, although likely with lower pathogenesis than H. pylori.

Molecular epidemiologic characteristics of Streptococcus pneumoniae isolates from children with meningitis in Japan from 2007 through 2009.

We examined associations of serotypes with multilocus sequence typing (MLST) data for 7 housekeeping genes and the genotype concerning penicillin resistance based on penicillin-binding protein (PBP) alterations in Streptococcus pneumoniae isolates from children with meningitis. From throughout Japan, we collected 115 pneumococcal isolates from the cerebrospinal fluid of patients 15 years old or younger from January 2007 to December 2009. We then carried out serotyping, MLST, and genotypic classification. Isolates included 24 serotypes and 52 sequence types (STs) according to MLST, of which 18 were novel. The 4 predominant serotypes included a variety of STs: 14 STs in serotype 6B (n = 24), 2 STs in 19F (n = 17), 6 STs in 23F (n = 14), and 5 STs in 14 (n = 11). Resistance genotypes included 6 types: 44.3% for gPRSP (pbp1a + 2x + 2b), 13.9% for gPISP (pbp1a + 2x), 9.6% for gPISP (pbp2x + 2b), 19.1% for gPISP (pbp2x), 3.5% for gPISP (pbp2b), and 9.6% for gPSSP. Interestingly, the most prevalent serotype of 6B included 7 newly identified STs and a variety of genotypes for resistance. STs in serotypes 23F and 14 were highly diverse, but not in 19F. These results suggest that various genetic elements in S. pneumoniae might be intrinsically susceptible to genetic mutations and recombination, with acceleration of emergence reflecting selection pressures such as antibiotic overuse.

[Histopathological Diagnosis of Invasive Fungal Infections in Formalin-Fixed and Paraffin-Embedded Tissues in Conjunction with Molecular Methods].

The main objective of this study was to evaluate the relationship between histopathology, polymerase chain reaction (PCR), and in situ hybridization (ISH) for the identification of causative fungi in formalin-fixed and paraffin-embedded (FFPE) tissue specimens. Since pathogenic fungi in tissue specimens can be difficult to identify morphologically, PCR and ISH have been usually employed as auxiliary procedures. However, little comparison has been made on the sensitivity and specificity of PCR and ISH using FFPE specimens. Therefore, to compare and clarify the reproducibility and usefulness of PCR and ISH as auxiliary procedures for histological identification, we performed histopathological review, PCR assays, and ISH to identify pathogenic fungi in 59 FFPE tissue specimens obtained from 49 autopsies. The following are the main findings for this retrospective review: i) even for cases classified as "mold not otherwise specified" (MNOS), two cases could be identified as Aspergillus species by molecular methods; ii) all cases classified as non-zygomycetes mold (NZM) were Aspergillus species and were not identified by molecular methods as other fungi; iii) all 3 cases classified as zygomycetes mold (ZM) could be identified by molecular methods as Mucorales; iv) except for 1 case identified by molecular methods as Trichosporon spp., 5 cases were originally identified as dimorphic yeast (DY). As a measure of nucleic acid integrity, PCR and ISH successfully detected human and fungal nucleic acids in approximately 60% of the specimens. Detection of Aspergillus DNA by nested PCR assay and by ISH against the A. fumigatus ALP gene were similarly sensitive and significant (p<0.01). Thus, our findings demonstrated the potential risk of error in the classification of fungi based on pathological diagnosis. Combining molecular methods such as ISH and PCR on FFPE specimens with pathological diagnosis should improve diagnostic accuracy of fungal infection.

Technical Aspects and Applications for Developing in situ Hybridization Procedures for Formalin-Fixed and Paraffin-Embedded (FFPE) Tissues for Diagnosis of Fungal Infections.

Although histopathology is required for definitive diagnosis of fungal infections, conclusive identification and discrimination of fungi in tissue sections and cytological preparations remain technically difficult. Therefore, new diagnostic tools are needed for the routine diagnosis of pathogenic fungi. In situ hybridization (ISH) is a non-culture based procedure that has many advantages over traditional diagnostics for identification of pathogenic fungi in histological specimens. This review highlights the basic ISH technique, with particular emphasis on using pretreatment of tissue sections prior to hybridization to solve problems associated with formalin fixation. With this modification, ISH has become a valuable tool that complements conventional histopathological diagnoses in formalin-fixed and paraffinembedded (FFPE) tissues. However, understanding the limitations imposed by formalin fixation is essential in developing suitable ISH protocols for fungal identification.

Comparison between the effectiveness of polymerase chain reaction and in situ hybridization in detecting the presence of pathogenic fungi by using the preserved DNA in formalin-fixed and paraffin-embedded tissues.

In situ hybridization (ISH) has been recognized as an important technique for identifying the causative fungi in the foci of infection observed in histopathological specimens which was processed from formalin-fixed and paraffin-embedded (FFPE) tissues. However, few basic studies have conducted an evaluation of the DNA preservation for use in ISH in comparison to polymerase chain reaction (PCR). The latter is a DNA amplification-based modality. In the present study, we analyzed 65 FFPE lung tissue specimens collected from autopsy cases for comparing the usefulness of ISH and PCR analysis. As a result, the positive identification rates for PCR were strikingly low; a majority of these results can be assumed to be false negative because the presence of fungi had been confirmed by histopathological analysis. In contrast, panfungal ISH targeting of the 28S rRNA showed a higher sensitivity than the 230-bp panfungal PCR primers did (80.0% versus 4.6%, respectively). Furthermore, over 60% of the samples we examined showed a favorable intensity of the ISH signal. Therefore, in conventional postmortem FFPE tissues, the state of DNA preservation may be more favorable for ISH than PCR analysis.

Application of in situ hybridization to tissue sections for identification of molds causing invasive fungal infection.

The present article describes our studies to know the usefulness of in situ hybridization (ISH) to identify various kinds of mold observed in tissue sections and / or cytological preparations from the lesions of patients with invasive fungal infection. To establish the precise procedure for ISH in formalin-fixed and paraffin-embedded sections, various pretreatments were attempted. The condition finally chosen is written here providing a favorable outcome regarding to both intensity and specificity of signals on outline of molds observed in the tissue sections when specimens were treated with both heat and proteinase K and, solutions were adjusted to higher pH value.Therefore, usefulness of promising probes, two each DNA and peptide nucleic acid (PNA) were verified with a favorable pretreatment condition, using lungs of mice experimentally infected and / or those obtained from autopsies with invasive mold infection. As the result, DNA probes targeting alkaline proteinase (ALP) gene and retrotransposon Afut-1 gene of Aspergillus fumigatus showed specific signal intensity for the Aspergillus species and A. fumigatus, respectively. PNA probes for Candida albicans and the Fusarium species also showed satisfactory specificity. We wish to emphasize that ISH can be a valuable tool to identify medically important molds in formalin-fixed and paraffin-embedded tissue sections or cytological preparations.