BACKGROUND AND OBJECTIVE

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as the causative agent of COVID-19 has significantly challenged the public health landscape in late 2019. After almost 3 years of the first ever SARS-CoV-2 case, the World Health Organization (WHO) declared the end of this global health emergency in May 2023. Although, despite the subsequent drop of COVID-19 cases, the SARS-CoV-2 infection still exhibited multiple waves of infection, primarily attributed to the appearance of new variants. Five of these variants have been classified as Variants of Concern (VOC): Alpha, Beta, Gamma, Delta, and the most recent, Omicron. Therefore, the development of methods for the timely and accurate detection of viral variants remains fundamental, ensuring an ongoing and effective response to the disease. This study aims to evaluate the feasibility of the application of an in-house approach in genomic surveillance for the detection of SARS-CoV-2 variants using in silico designed primers.

The primers used for the study were particularly designed based on conserved regions of certain genes in the virus, targeting distinct mutations found in known variants of SARS-CoV-2. Viral RNA extracts from nasopharyngeal samples (n=14) were subjected to quantitative and qualitative tests (Nanodrop and AGE). Selected samples were then analyzed by RT-PCR and amplicons were submitted for sequencing. Sequence alignment analysis was carried out to identify the prevailing COVID-19 variant present in the sample population.

The study findings demonstrated that the in-house method was able to successfully amplify conserved sequences (spike, envelope, membrane, ORF1ab) and enabled identification of the circulating SARS-CoV-2 variant among the samples. Majority of the samples were identified as Omicron variant. Three out of four designed primers effectively bound into the conserved sequence of target genes present in the sample, revealing the specific SARSCoV-2 variant. The detected mutations characterized for Omicron found in the identified lineages included K417N, S477N, and P681H which were also identified as mutations of interest. Furthermore, identification of the B.1.448 lineage which was not classified in any known variant also provided the potential of the developed in-house method in detecting unknown variants of COVID-19.

Among the five VOCs, Omicron is the most prevalent and dominant variant. The in-house direct PCR product sequencing surveillance (DPPSS) method provided an alternative platform for SAR-CoV-2 variant analysis which is accessible and affordable than the conventional diagnostic surveillance methods and the whole genome sequencing. Further evaluation and improvements on the oligonucleotide primers may offer significant contribution to the development of a specific and direct PCRbased detection of new emerging COVID-19 variants.

BACKGROUND AND OBJECTIVE

Nontuberculous mycobacteria (NTM) lung disease appears like tuberculosis infection but is resistant to primary anti-tuberculosis drugs. Hence, patients whose sputum sample tests positive for acid-fast bacilli (AFB) and bacterial culture for several times should be assessed for colonization or infection with NTM in a damaged lung secondary to TB. In such cases, though drug-resistant TB may be adequately treated, treatment may need to be directed towards the NTM as well. In NTM therapy, the duration and choice of treatment agent is based upon the specific organism and disease extent. This study used one-step multiplex PCR (mPCR) assay for rapid differentiation of solid cultures in Ogawa medium as Mycobacterium tuberculosis (MTB) and/or NTM.

A total of 80 stocked isolates obtained from the Lung Center of the Philippines from January to December 2018 were screened for NTM in terms of growth in Ogawa medium, acid fastness, and MPT64 TB antigen test result. These were from sputum specimens of multidrug-resistant tuberculosis (MDR-TB) patients. DNA was extracted from cultures (n=55) grown in Ogawa medium and one-step mPCR was performed to identify NTM to the species level.

Out of 80 samples screened, a total of 55 isolates were identified as NTM. One-step mPCR identified 12.73% (7/55) as M. abscessus, 34.55% (19/55) as M. massiliense, 1.82% (1/55) as M. kansasii, and 50.91% (28/55) were identified only up to genus Mycobacteria spp. Neither M. avium complex nor M. intracellulare was identified among the samples tested.

One-step mPCR was able to identify isolates as MTB or NTM coinciding with the initial screening using MPT64 TB antigen test. Multiplex PCR has given a more specific identificati on to the species level. The use of mPCR in identifying MTB and clinically significant NTM’s is suitable for the adequate treatment of mycobacterial infection.

Human ; Bacteria ; Antimicrobial Stewardship ; Insemination, Artificial, Heterologous ; Multiplex Polymerase Chain Reaction ; Polymerase Chain Reaction

OBJECTIVES

To validate a method in detecting SARS-CoV-2 via RT-qPCR in pregnant and non-pregnant samples other than nasopharyngeal swabs and/or oropharyngeal swabs such as cervical, rectal, amniotic fluid, placental, umbilical cord blood, and breastmilk.

We performed a validation experiment using MGI easy extraction kits and BGI PCR kits on non-conventional specimens, including cervical, rectal, amniotic fluid, placental, umbilical cord blood, and breastmilk to detect and confirm the presence of SARS-CoV-2. In addition, we tested the validated method on 572 purposively sampled field-collected non-conventional specimens from a cohort of 109 unvaccinated pregnant and 47 unvaccinated non-pregnant women to assess which candidate non-conventional maternal- and fetal-associated specimens may contribute to maternal-fetal viral vertical transmission.

Positive detection of SARS-CoV-2 viral RNA in non-conventional specimens was demonstrated and verified. Of the 572 non-conventional samples tested, 1.8% (10/572) were positively validated by RT-qPCR for SARS-CoV-2 in the maternal-associated specimens particularly the rectal (5), placental (1), and cervical (4) swabs among six pregnant and four non-pregnant individuals. In contrast, no SARS-CoV-2 viral RNA was detected in fetal-associated specimens.

The results of the validation study may serve as an additional diagnostic screening layer to support maternal-child care. Furthermore, viral detection in these non-conventional maternal specimens may also be utilized to provide guidance in the clinical management of neonates, and pregnant women during delivery.

BACKGROUND

Broad  Panel Respiratory Multiplex PCR (Pneumonia Panel) tests a panel of bacteria and viruses associated with community acquired pneumonia (CAP) which help streamline antimicrobial therapy. Recently, pneumonia panel aids clinicians in early streamlining of antimicrobials as opposed to waiting for bacterial culture results [2].

To determine whether the use of pneumonia panel improves the overall survival rate, length of hospital stay, and number of antibiotic free days among hospitalized CAP patients.

In this RCT, adult patients admitted for CAP were randomized to perform pneumonia panel and sputum culture (pneumonia panel group) versus sputum culture only (control group). The results were relayed to the medical team and were incorporated into the medical records. Length of hospital stay, antibiotic free days in day 28, and mortality rates were the primary outcomes measured.

Eighty participants completed the study. There was no significant difference in the length of hospital stay (p-value 0.073, 95% C.I.), duration of antibiotic therapy (p-value 0.332, 95% C.I.), and mortality rates (p-value 0.570, 95% C.I.) between the 2 groups.

Routine use of pneumonia panel does not significantly reduce length of hospital stay, duration of antibiotic therapy, and mortality rates among admitted patients with moderate to severe CAP. The benefit of pneumonia panel was seen on early detection of drug resistant pathogen resulting in early antibiotic escalation and shorter duration of antibiotic therapy. Further studies are necessary to show its benefit in the high risk population.

OBJECTIVE: To analyze the serological characteristics and molecular mechanism for an individual with p phenotype. METHODS: An individual with p phenotype upon blood group identification at Jiaxing Blood Center in May 2021 was analyzed. ABO, RhD and P1PK blood groups and irregular antibodies in her serum were identified using conventional serological methods. The encoding region of α1, 4-galactosyltransferase gene (A4GALT) encoding P1 and Pk antigens was analyzed by polymerase chain reaction-sequence-based typing (PCR-SBT). RESULTS: The individual was A group, RhD positive and had a p phenotype of the P1PK blood group system. Anti-PP1Pk was discovered in her serum. Sequencing analysis revealed that she has harbored a homozygous c.343A>T variant of the A4GALT gene. CONCLUSION The homozygous c.343A>T variant of the A4GALT gene probably underlay the p phenotype in this individual.
Female ; Animals ; Blood Group Antigens ; Homozygote ; Phenotype ; Polymerase Chain Reaction ; Sequence Analysis, DNA

Mycoplasma species (spp.) are bacteria that are difficult to detect. Currently, the polymerase chain reaction (PCR) is considered the most effective diagnostic tool to detect these microorganisms in both human and veterinary medicine. There are 13 known species of human Mycoplasma and 15 species of canine Mycoplasma. Owing to the difficulties in identifying the individual species of Mycoplasma, there is a lack of information regarding which species are saprophytic and which are pathogenic. The prevalence of the individual species is also unknown. In addition, in both humans and dogs, the results of some studies on the impact of Mycoplasma are conflicting. The presence of Mycoplasma spp. on the epithelium of reproductive tract is often associated with infertility, although they are also detected in healthy individuals. The occurrence of Mycoplasma spp. is more common in dogs (even 89%) than in humans (1.3%-4%). This is probably because the pH of a dog's genital is more conducive to the growth of Mycoplasma spp. than that of humans. Phylogenetically, human and canine Mycoplasma are related, and majority of them belong to the same taxonomic group. Furthermore, 40% of canine Mycoplasma spp. are placed in common clusters with those of human. This suggests that species from the same cluster can play a similar role in the canine and human reproductive tracts. This review summarizes the current state of knowledge about the impact of Mycoplasma on canine and human male fertility as well as the prospects of further development in this field.
Humans ; Dogs ; Male ; Animals ; Mycoplasma/genetics* ; Infertility ; Semen Analysis ; Polymerase Chain Reaction/methods* ; Prevalence ; Semen/chemistry*

OBJECTIVE: To confirm the HLA genotypes of the samples including 4 cases of magnetic bead probe HLA genotyping result pattern abnormality and 3 cases of ambiguous result detected by PCR sequence-specific oligonudeotide probe (SSOP) method. METHODS: All samples derived from HLA high-resolution typing laboratory were detected by PCR-SSOP. A total of 4 samples of magnetic bead probe HLA genotyping result pattern abnormality and 3 samples of ambiguous result were further confirmed by PCR sequence-based typing (SBT) technology and next-generation sequencing (NGS) technology. RESULTS: A total of 4 samples of magnetic bead probe HLA genotyping result pattern abnormality were detected by PCR-SSOP method. The results of SBT and NGS showed that the HLA-A genotype of sample 1 did not match any known genotypes. NGS analysis revealed that the novel allele was different from the closest matching allele A*31:01:02:01at position 154 with G>A in exon 2, which resulting in one amino acid substitution at codon 28 from Valine to Methionine (p.Val28Met). The HLA-C genotype of sample 2 was C*03:119, 06:02, sample 3 was C*03:03, 07:137, and sample 4 was B*55:02, 55:12. A total of 3 samples with ambiguous result were initially detected by PCR-SSOP method. The re-examination results of SBT and NGS showed that the HLA-B genotype of sample 5 was B*15:58, 38:02, sample 6 was DRB1*04:05, 14:101, and sample 7 was DQB1*03:34, 05:02. Among them, alleles C*03:119, C*07:137 and DRB1*14:101 were not included in the Common and Well-documented Alleles (CWD) v2.4 of the Chinese Hematopoietic Stem Cell Donor Database. CONCLUSION The abnormal pattern of HLA genotyping results of magnetic probe by PCR-SSOP method suggests that it may be a rare allele or a novel allele, which needs to be verified by sequencing.
Humans ; Alleles ; Polymerase Chain Reaction ; Genotype ; High-Throughput Nucleotide Sequencing ; Histocompatibility Testing/methods* ; Technology

OBJECTIVES: To compare the effects of cell lysis method and magnetic beads method in forensic DNA identification and to explore these two methods in forensic DNA identification. METHODS: The genome DNA of THP-1 cells in different quantities was extracted by the cell lysis method and magnetic beads method, and the DNA content was quantified by real-time quantitative PCR. The cell lysis method and magnetic beads method were used to type the STR of human blood with different dilution ratios. RESULTS: When the numbers of THP-1 cell were 100, 400 and 800, the DNA content extracted by cell lysis method were (1.219±0.334), (5.081±0.335), (9.332±0.318) ng, respectively; and the DNA content extracted by magnetic beads method were (1.020±0.281), (3.634±0.482), (7.896±0.759) ng, respectively. When the numbers of THP-1 cells were 400 and 800, the DNA content extracted by the cell lysis method was higher than that by the magnetic beads method. The sensitivity of cell lysis method and magnetic beads method was similar in STR typing of human blood at different dilution ratios. Complete STR typing could be obtained at 100, 300 and 500-fold dilutions of blood samples, but could not be detected at 700-fold dilution. STR typing of undiluted human blood could not be detected by cell lysis method. CONCLUSIONS The cell lysis method is easy to operate and can retain template DNA to the maximum extend. It is expected to be suitable for trace blood evidence tests.
Humans ; Forensic Medicine ; DNA/genetics* ; Real-Time Polymerase Chain Reaction ; Magnetic Phenomena ; DNA Fingerprinting/methods* ; Microsatellite Repeats

Objective: To investigate the relationship between amino acid variations of respiratory syncytial virus (RSV) nonstructural protein (NS) 1 and the clinical characteristics. Method: A retrospective case review was conducted. From December 2018 to January 2020, a total of 81 cases of hospitalized children who were tested only positive for RSV by RT-PCR or PCR at the Department of Respiratory Medicine, Children's Hospital of Chongqing Medical University were included in the study. The NS1 genes of RSV subtype A and subtype B were amplified by PCR and sequenced. The amino acid sequences were analyzed. The Chi-square test and Mann-Whitney rank sum test were used to compare the clinical characteristics and type Ⅰ interferon levels of children with or without NS1 variation in the variation and non-variation groups. Results: Among 81 cases, there were 58 males and 23 females. There were 11 cases in the variation group, the age of onset was 2.0 (1.0, 11.0) months, included 4 cases of subtype A (variant sites were: 2 cases for Lys33Gln, one case for Gly2Asp, Pro67Ser, Leu137Phe, respectively) and 7 cases of subtype B (variant sites were: two cases for Val121Ile, one case for Tyr30Cys, Val65Met, Asn85Ser, Ser118Asn, Asp124Asn, respectively). These variant sites all appeared at a very low frequency 0.08 (0.04, 0.29) % in the NCBI PROTEIN database. There were 70 cases in non-variation group, the onset age was 3.5 (1.0, 7.0) months. The proportion of dyspnea in the variation group was higher than that in the non-variation group (10/11 vs. 47% (33/70), χ²=7.31, P<0.01). Conclusions: There are some variant sites in nonstructural protein NS1 of RSV. Children may be prone to have dyspnea with NS1 variations.
Child ; Male ; Female ; Humans ; Infant ; Respiratory Syncytial Virus Infections ; Amino Acids ; Retrospective Studies ; Respiratory Syncytial Virus, Human/genetics* ; Polymerase Chain Reaction