Hypervirulent Klebsiella pneumoniae (hvKP) is an important human pathogen associated with pneumonia, liver abscess and endophthalmitis. However, current methods are unable to distinguish hvKP from classic K. pneumoniae (cKP), which often leads to delays in the diagnosis and treatment of hvKP infections. Here, we established a fluorescence assay based on Pyrococcus furiosus Argonaute (PfAgo) combined with polymerase chain reaction (PCR) or recombinase-aided amplification (RAA) to assist in the detection of hvKP. Specific primers, guide DNAs (gDNAs), and probes were designed to target the hvKP genes iucA and peg344 and the conserved region of the KP genome. After optimizing the reaction conditions, the limits of detection (LODs) for PCR-PfAgo and RAA-PfAgo were 1-10 copies/mu L and 101-102 copies/mu L, respectively. There was no cross-reactivity with nine other common pathogens. For detection in clinical bacterial suspensions at different concentrations, 1 CFU/mL KP could be detected via PfAgo-assisted detection. Its applicability was confirmed by the evaluation of 50 clinical specimens. The accuracy of the KP strain was 100 % (50/50) compared with that of cultivation and matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) technology. Compared to the traditional PCR assay for five virulence genes (iucA, iutA, iroB, rmpA, and rmpA2), the PCR/RAA-PfAgo system detects hvKP with a high accuracy rate of 91.67 % (22/24). In conclusion, this novel PCR/RAA-PfAgo detection system is an effective tool for prompt and precise detection of KP and hvKP, even in resource-limited or non- laboratory settings.

This study introduces an efficient RPA-PfAgo detection system for the MTHFR C677T polymorphism, proposing a potential strategy to simplify the genotyping process. By optimizing recombinase polymerase amplification (RPA) with Pyrococcus furiosus Argonaute (PfAgo) nucleases, we achieved DNA amplification at a constant temperature. The assay was fine-tuned through meticulous primer and guide DNA selection, with optimal conditions established at 2.0 mu L of MgAc, a reaction temperature of 42 degrees C, and a 10-minute reaction time for RPA. Further optimization of the PfAgo cleavage assay revealed the ideal concentrations of MnCl2, guide DNA, molecular beacon probes, the PfAgo enzyme, and the RPA product to maximize sensitivity and specificity. Clinical validation of 20 samples showed 100% concordance with Sanger sequencing, confirming the method's precision. The RPA-PfAgo system is a promising tool for on-site genotyping, with broad applications in personalized medicine and disease prevention.

Objective The α-globin fusion gene between the HBA2 and HBAP1 genes, is clinically important in thalassemia screening because this fusion gene can cause severe hemoglobin (Hb) H disease when combined with α0 -thalassemia (α0 -thal). In this study, we evaluate the red blood cell parameters of α-thalassemia fusion gene in southern China.Method Study samples suspected of α-thalassemia fusion gene were collected and confirmed by PCR-sequencing from one medical lab center in southern China. Their genotypes and phenotypes were analyzed.Results A total of 266 cases of α-thalassemia fusion gene were confirmed in our lab from 2017 to 2023, most of them were from Hainan province (169 cases) and Huadu district of Guangzhou (21 cases), the nationality of 143 cases from Hainan was identified, with 71.3% (102/143) being from the Li minority. The Hb, MCV, MCH for αα/(αα)fusion in adult males were 143.5±11.83g/L, 81.51±4.39 fl, and 26.26±1.29 pg, respectively; and in females, they were 126.69±12.89 g/L, 80.10±4.05 fl, 25.8±2.04 pg, respectively. All 12 cases (αα) Fusion/ --SEA showed anemia with decreased Hb, MCV and MCH.Conclusion The carriers of α-globin fusion gene heterozygotes are clinically silent and exhibit an α+ phenotype. Individuals with (αα)Fusion/--SEA show apparent anemia. This α-globin fusion gene is relatively common in southern China, specifically among the Li minority of Hainan province. Therefore, it should be taken into account for genetic counseling purposes.

Foodborne illness caused by Salmonella spp. is one of the most prevalent public health problems globally, which have brought immeasurable economic burden and social impact to countries around the world. Neither current nucleic acid amplification detection method nor standard culture method (2 -3 days) are suitable for field detection in areas with a heavy burden of Salmonella spp. Here, we developed a highly sensitive and accurate assay for Salmonella spp. detection in less than 40 min. Specifically, the invA gene of Salmonella spp. was amplified by recombinase polymerase amplification (RPA), followed by Pyrococcus furiosus Argonaute ( Pf Ago)- based target sequence cleavage, which could be observed by a fluorescence reader or the naked eye. The assay offered the lowest detectable concentration of 1.05 x 10 1 colony forming units/mL (CFU/mL). This assay had strong specificity and high sensitivity for the detection of Salmonella spp. in field samples, which indicated the feasibility of this assay.

Background Human papillomavirus (HPV) is the main cause of cervical cancer. The aim of the present study was to investigate HPV DNA detection and genotyping on paired genital and urine samples and to evaluate if urine samples could be used to monitor HPV infection. Methods Study subjects were recruited from one local hospital in Guangdong of China from September 1, 2011, to June 30, 2012. They were invited to participate if they have taken an HPV genotyping assay for clinical diagnosis of the genital-urinary disease or for a health check-up 3–5 days ago. DNA was extracted from paired genital and urine samples; genotyping was performed with the GenoArray assay. Results A total of 250 patients were recruited, which included 203 females and 47 males. Our results showed that the overall agreement on HPV status between the paired samples was 77.1% (155/201, 95% CI: 0.713–0.829) for females, with a kappa value of 0.523 (95% CI: 0.469–0.632), while the agreement was extremely low in the paired male samples. As to individual genotyping, the greatest agreement was found for HPV16 type-specific identification in females (96.02%, 0.933–0.987), followed by the other 12 high oncogenic risk (HR-HPV) types, while the agreement for low-risk HPV detection is poor (κ < 0.6). Agreement between paired samples showed that HPV detection had a significantly greater concordance in the samples obtained in females than males (p = 0.002). Moreover, the agreement for low-risk HPV detection was significantly lower as compared to HR-HPV detection (48.1% vs. 62.3%, p = 0.044). Conclusion Despite reduced sensitivity, HPV detection in urine closely represents the same trend that is seen with genital sampling. Urine appears to be an appropriate surrogate sample for HPV DNA detection in women with very limited access to healthcare, while the utility of urine for HPV DNA detection in males is less certain.

Background: Thalassemia presents a higher incidence in southern China. The objective of this study is to analyze the genotype distribution of thalassemia in Yangjiang, a western city of Guangdong Province in China. Methods: The genotypes of suspected cases with thalassemia were tested by PCR and reverse dot blot (RDB). Unidentified rare thalassemia genotypes of the samples were further ascertained by PCR and direct DNA sequencing. Results: Among 22467 suspected cases with thalassemia, 7658 cases were found with thalassemia genotypes using our PCR-RDB kit. Among these 7658 cases, 5313 cases were found with α-thalassemia (α-thal) alone, -- SEA /αα was the most common genotype, accounting for 61.75% of α-thal genotypes, and the following mutations were found: α 3.7 /αα, -α 4.2 /αα, α CS α/αα, α WS α/αα, and α QS α/αα. A total of 2032 cases were found with β-thalassemia (β-thal) alone. β CD41-42 /β N , β IVS−II−654 /β N , and β −28 /β N accounted for 80.9% of all β-thal genotypes, and the following genotypes were found: β CD17 /β N , β CD71-72 /β N , and β E /β N . Compound heterozygotes of β-thal and β-thalassemia homozygotes were identified in 11 and five cases, respectively, in this study. α-thal combined with β-thal was identified in 313 cases, showing 57 genotype combinations of the coincidence of both Hb disorders; one extreme patient had a genotype of -- SEA /α WS α and β CD41-42 /β −28 . In addition, four rare α -mutations (-- THAI , HKαα, Hb Q-Thailand, and CD31 AGG>AAG) and six rare β-mutations (CD39 CAG>TAG, IVS-Ⅱ-2 (−T), −90(C>T), Chinese G γ + ( Aγδβ)0 , CD104 (-G), and CD19 A>G) were also found in this study population. Conclusion: This study provided detailed genotypes of thalassemia in Yangjiang of western Guangdong Province in China and reflected the complexity of genotypes in this high-prevalence region, and this would be valuable for diagnosis and counseling for thalassemia in this area.

Objective To evaluate a novel reverse dot blot assay for the simultaneous detection six types of common α-thalassaemia alleles (three deletional and three common non-deletional mutations) and 19 types of common β-thalassaemia alleles in a Chinese population. Methods Genomic DNA samples were collected from three hospitals in southern China. The novel thalassaemia gene assay involved one multiplex polymerase chain reaction amplification system and one round of hybridization. Each of the clinically validated DNA samples was re-tested using the new multiplex polymerase chain reaction/reverse dot blot assay II (M-PCR/RDB II) assay in a double-blind manner. Results A total of 1060 unrelated study participants, including 829 patients with thalassaemia and 231 healthy control subjects, were analysed. The whole PCR and RDB procedures were completed in 260 min. All the samples, including heterozygous thalassaemia, homozygous thalassaemia and compound heterozygous thalassaemia, were correctly genotyped, yielding 100% concordance with the reference assays. HKαα/-- SEA and HKαα/−α 4.2 , which were not included in the detection panel, yielded a contradictory result with this new assay. Conclusion The novel M-PCR/RDB II assay was simple, rapid and accurate, suggesting that it could be used for the genetic screening and clinical diagnosis of common α-thalassaemia and β-thalassaemia variants in Chinese populations.

Genetic mutations can cause life-threatening diseases such as cancers and sickle cell anemia. Gene detection is thus of importance for disease-risk prediction or early diagnosis and treatment. Apart from genetic defects, gene detection techniques can also be applied to gene-related diseases with high risk to human health such as human papillomavirus (HPV) infection. HPV infection has been strongly linked to cervical cancer. To achieve a high-throughput HPV gene detection platform, the flow-through hybridization system appears to be one of the commercialized diagnostic techniques for this purpose. The flow-through hybridization technique is based on a vacuum-guided flow of DNA fragments which is continuously directed toward the oligoprobes that are immobilized on the testing membrane. However, the conventional colorimetric method and signal read-out approach suffers a problem of low sensitivity. On the contrary, fluorescence approaches allow more sensitive detection and broad sensing ranges. In this work, a fluorescent dye HCAP, which possesses aggregation-induced emission (AIE) properties and is responsive to alkaline phosphatase, was developed and applied to the flow-through hybridization platform to achieve HPV genome diagnosis of clinical samples. Also, an automatic membrane reader was constructed based on the AIE-based diagnosis platform which can identify the diagnostic result of patient DNA with a total concordance rate of 100% in the clinical trial.

Background The emerging Coronavirus Disease-2019 (COVID-19) has challenged the public health globally. With the increasing requirement of detection for SARS-CoV-2 outside of the laboratory setting, a rapid and precise Point of Care Test (POCT) is urgently needed. Methods Targeting the nucleocapsid (N) gene of SARS-CoV-2, specific primers, and probes for reverse transcription recombinase-aided amplification coupled with lateral flow dipstick (RT-RAA/LFD) platform were designed. For specificity evaluation, it was tested with human coronaviruses, human influenza A virus, influenza B viruses, respiratory syncytial virus, and hepatitis B virus, respectively. For sensitivity assay, it was estimated by templates of recombinant plasmid and pseudovirus of SARS-CoV-2 RNA. For clinical assessment, 100 clinical samples (13 positive and 87 negatives for SARS-CoV-2) were tested via quantitative reverse transcription PCR (RT-qPCR) and RT-RAA/LFD, respectively. Results The limit of detection was 1 copies/μl in RT-RAA/LFD assay, which could be conducted within 30 min at 39°C, without any cross-reaction with other human coronaviruses and clinical respiratory pathogens. Compared with RT-qPCR, the established POCT assay offered 100% specificity and 100% sensitivity in the detection of clinical samples. Conclusion This work provides a convenient POCT tool for rapid screening, diagnosis, and monitoring of suspected patients in SARS-CoV-2 endemic areas.

OBJECTIVE:To detect rare types of thalassemia mutations among southern Chinese population.METHODS:Peripheral blood samples from 327 patients from various regions of southern China were collected. The patients were suspected as rare-type thalassemia for their inconsistency between hematological phenotypes and results of routine mutation screening. The samples were further analyzed with GAP-PCR and DNA sequencing.RESULTS:One hundred and eight cases were diagnosed as rare types of thalassemia. Among whom 10 rare α-globin gene mutations including --THAI, HKα, αααanti3.7, αααanti4.2, -α2.8, -α27.6, CD74 GAC>CAC (Hb Q-Thailand), CD30 (-GAG), CD31 AGG>AAG and CD118 (+TCA), and 12 rare β-globin gene mutations including CD37 TGG>TAG, CD39 CAG>TAG/CD39 CAG>TAG, β II-2 (-T), -90(C>T), -31(A>C), -88(C>T), CD7(-A), CD138(+T), CD89-93 (--AGTGAGCTGCACTG), CD54-58 (-TATGGGCAACCCT), Chinese G γ +(A γδβ)0 and Vietnamese HPFH (HPFH-6) were identified. -88(C>T) (HBB: c.-138C>T) and CD39 CAG>TAG (HBB: c.118C>T) were discovered for the first time in Chinese population. CD7(-A) (HBB: c.23delA) and CD138(+T) (HBB: c.416_417insT) were new types of β-globin gene mutations.CONCLUSION:The present study have enriched the mutation spectrum of thalassemia in southern China, which has provided necessary information for its diagnosis.

In the present study, we describe the laboratory workflow and the clinical validation of a novel multiplex real-time PCR-based HPV assay in China. The cross-sectional validation analysis showed that this assay worked well for detection of 14 HR-HPV types and identification of HPV 16 and 18 in a single sensitive assay that is suitable for both clinical usage and high-throughput cervical screening purposes. We predict that this accurate, high-throughput and low-cost HPV assay can greatly reduce the heavy economic burden of HPV detection in China.

Objective To explore the correlation of HPV DNA test between gene-chip based on PCR technique and real-time fluorescent PCR in cervical exfoliated cells. Methods 2050 samples were measured by the gene-chip and real-time fluorescent PCR, which inconsistent results would be verified by sequencing, and statistical analysis of the consistent rate and positive rate. Results The total concordance rate, the positive concordance rate and the negative concordance rate of the two detection methods were more than 95.0%. The positive rate of HPV16 and HPV18 detected by fluorescence quantitative PCR method were 50.0% and 13.9%, respectively. Conclusion The consistence of two detection methods was good, and HPV12+2 type detection kit was suitable for application in the childbearing age women at risk of cervical cancer screening and follow-up.

Background: Human papilloma virus (HPV) infection was the main cause of cervical cancer. There were only a few reports and detailed data about epidemiological research of HPV infection in rural population of China.Materials and Methods: The cervical cells of rural Chaozhou women were collected, and multiplex real time PCR was firstly performed to detect high-risk HPV (HR-HPV) infection, which could detect 13 types of HR-HPV (types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, and 68). Then, HPV-positive samples were typed by HPV GenoArray test.Results: HR-HPV DNA was detected by multiplex real time-PCR in 3830 of 48559 cases (7.89%). There was a peak incidence in age of 55-60 years group, and a lower incidence in who lived in plain group compared with suburban, mountain and seashore group. 3380 cases of HPV positive sample were genotyped, 11.01% (372/3380) cases could not be classified, among the typed 3008 cases, 101 cases were identified without HR-HPV type infection, 2907 cases were infected with one HR-HPV type at least, the 6 most common HR-HPV types in descending order of infection, were type 52 (33.4%, 16 (20.95%), 58 (15.93%), 33 (9.94%), 68 (9.22%) and 18 (8.36%). The combined prevalence of HPV types 16 and 18 accounted for 28.52% of total infection. However, type 52 plus 58 presented 48.23% of total infection. 2209/2907 cases were infected with a single HPV type and 698/2907 cases were infected with multiple types, and multiple infection constituent ratio increased with age, with a peak incidence in age 55-60 years group.Conclusions: Our findings showed low prevalence of HPV vaccine types (16 and 18) and relatively high prevalence of HPV-52 and -58, support the hypothesis that the second-generation HPV vaccines including HPV-52 and -58 may offer higher protection for women in rural Guangdong Province.

Background: Human papillomavirus (HPV) infections are associated with cervical cancer. There were only a few reports and detailed data about epidemiological research of HPV infection in general population of China.Aims: To determine the prevalence of genital HPV infection in Chinese women of Guangdong province.Methods: A total of 1705 women were screened by gene chip. All HPV-positive women were further examined by ThinPrep liquid-based cytology test (TCT), and the cervical biopsies of those women with positive HPV-DNA and abnormal TCT were collected for pathological diagnosis.Results: The overall HPV prevalence was 9.03% (154 of 1705), and 72.3% (126 of 154) of total positive samples were high-risk types, with higher prevalence of types 52, 58, 16, 18 and CP8304. For women aged 51 years or older, the overall high-risk HPV prevalence was 12.2% (24 of 179), which was obviously higher than those of other age groups (P < 0.05).Conclusions: Our results showed that the HPV prevalence in Guangdong is very similar to the world level. Unlike most previous studies, our findings suggest that HPV prevalence increased with age, and that the predominant genotypes in this area were HPV 52 and 58.