The Multiplex-RT-Nested-PCR assay, as previously reported, has been used widely to detect Human parainfluenza virus (HPIV). The assay has high sensitivity to HPIV genes and the capability of typing HPIV. However, the lengths of amplified products by its nested-PCR are too short for constructing phylogenetic trees.
Therefore, we tried to develop a novel Multiplex-RT-Nested-PCR assay that has the ability to amplify the gene products with sufficient length to construct phylogenetic trees as well as high sensitivity for HPIV genes. We designed new primers with reference to base sequences of the HN region and we could amplify various length of PCR products with its nested-PCR, 652 bp in type 1, 950 bp in type 2, 843 bp in type 3, and 552 bp in type 4.
We detected HPIV genes with the novel assay from all 193 clinical specimens, the same as the assay previously reported.
In addition, the novel assay showed a higher percentage of specimens that were positive for HPIV by the 1st-PCR (82.4%), compared with the previously-reported assay (50.3%). The novel assay has no cross reactivity with the other 12 kinds of viruses that cause respiratory illness.
Moreover, we could construct the phylogenetic trees from the sequences with over 500 nt length acquired by the novel assay. By the phylogenetic tree analysis, most of the sequences were classified to existing reported clusters and subtypes.
In conclusion, the newly developed Multiplex-RT-Nested-PCR assay was useful to detect and analyze HPIV genes from clinical specimens.
In recent years, a highly sensitive HBs antigen measurement reagent has been developed and its usefulness has been proposed. However, as a harmful effect of its high sensitivity, there is concern about a decrease in specificity (false positive findings). In order to avoid false positives, it is recommended to perform suppression tests using HBs antibody in a low value positive case, but many institutions have not followed this recommendation. Therefore, in institutions that have introduced a highly sensitive HBs antigen reagent but do not perform suppression tests, HBs antigen false positive cases may be increasing. In April 2018, the highly sensitive HBs antigen reagent “Lumipulse Presto HBsAg-HQ”was improved for the purpose of increasing the specificity. In this report, the performance of this reagent was examined including comparison with the reagent before improvement.
The subjects were seven specimens judged false positives based on “Lumipulse Presto HBsAg-HQ” before improvement. The criteria for false positives in this study were “HBs antigen quantitative value is not less than cut-off (0.005IU/mL) and negative in the inhibition test.”For the measurement, a fully automated chemiluminescent enzyme immunoassay system “Lumipulse L 2400”was used.
As a result of measuring the HBsAg value using the reagent after the improvement, HBsAg was less than the cut-off value (0.005IU/mL) in 5 samples out of 7 specimens which were regarded as false positives before improvement. The detection limit was detectable up to 0.0015IU / mL, and no change was observed compared to before the improvement. We investigated the possibility of a nonspecific reaction, using one of the specimens considered to have nonspecific reactions to labeled ALP. The monthly false positive rate before improvement was 0.26 %, but the average tended to decrease to 0.09 % after the change.
In conclusion, it can be expected that the false positive rate was reduced by “Lumipulse Presto HBsAgHQ”after improvement, so there is a possibility of reducing the number of suppression tests and “false reports”.
Entamoeba histolytica infections comprising enterocolitis (54 cases), liver abscesses (58 cases) and asymptomatic carriers (17 cases) were retrospectively studied based on the medical records of patients diagnosed at the Department of Infectious Diseases of Tokyo Metropolitan Komagome Hospital during 1992-2000, with special reference to serum antibody titers (indirect haemagglutination test) to E. histolytica. As the timing and the frequency of antibody testings varied for each patient, the maximum antibody titers of individual cases were used as the representatives of antibody titers for E. histolytica. Sensitivity of the serodiagnosis to E. histolytica was 85.2% (46 in 54 cases) for amoebic colitis, 98.3% (57 in 58 cases) for amoebic liver abscesses,and 11.8% (2 in 17 cases) for asymptomatic carriers. Following assignation of patients with non-amoebic enterocolitis (28 cases) and non-amoebic space-occupying mass lesions of the liver (16 cases) to negative controls, the specificity of the serodiagnosis with the anti-amoebic antibody was 100% for both groups of the above mentioned patients with amoebic colitis and amoebic liver abscesses.
Febrile neutropenia is a serious complication during the neutropenic phase, especially in patients with leukemia or receiving hematopoietic stem cell transplantation. Although it has been reported that prophylactic fluoroquinolone could reduce the frequencies of bloodstream infections in these patients, the significance of obtaining two sets of blood cultures in patients receiving allogeneic hematopoietic stem cell plantation (allo-HSCT) remains unknown. The aim of this study was to clarify the significance of obtaining two sets of blood cultures in these patients.
; We retrospectively reviewed medical records of allo-HSCT patients with febrile neutropenia under fluoroquinolone prophylaxis during the period from January 2007 till February 2012. We divided this study period into two groups：phase I (January 2007 to December 2009；tosufloxacin 450mg/day) and phase II (January 2010 to February 2012；levofloxacin 500mg/day).
In 109 patients (phase I) and 147 patients (phase II), blood cultures were obtained at the proper timing in cases of febrile neutropenia. Obtaining two sets of blood cultures were recommended in phase II, leading to the increased rates of two sets of blood cultures in phase II (75 cases；51.0%) compared with those in phase I (4 cases；3.7%) There were significant differences between these rates (p .0001). Moreover, 29 cases (26.6%) in phase I and 59 cases (40.1%) in phase II were diagnosed as true bloodstream infections,which also showed significant differences (p = .03).
Our results showed the clinical significance of running two sets of blood cultures under fluoroquinolone prophylaxis. This practice is useful to determine whether the results of blood cultures are true or not, which might lead to setting the appropriate antimicrobial usage.
A 62-year-old immunocompetent male presented with a 20-day history of fever and a 2-day history of right facial swelling and trismus. The patient was diagnosed as having a buccal abscess suspected of odontogenic infection (OI) and treated with ceftriaxone and clindamycin. However, the patientʼs condition rapidly deteriorated with septic shock, acute respiratory distress syndrome, and disseminated intravascular coagulation due to severe OI. Antibiotics were switched to meropenem, and large amounts of fluids, noradrenaline,and hydrocortisone were intravenously administered. Although Eikenella corrodens and Slackia exigura were detected in both blood and abscess cultures, the patient was not diagnosed as having infective endocarditis. Facial swelling became worse again on day 10 and the wound was drained. The patient was discharged on day 41. Poor oral-hygiene and delay in patient consultation may be risk factors for severe OI. Clinical decision making would benefit by knowing that OI can cause severe, complicated infection in immunocompetent patients and that early recognition of severe disease signs such as trismus can lead to favorable outcomes.