Role of noscomial infection informatics surveillance system in the prevention and control of multidrug-resistant organisms infections

OBJECTIVE: To analyze the role of nosocomial infection informatics surveillance system in the prevention and control of multidrug-resistant organisms(MDROs) infections. METHODS: The First Affiliated Hospital of Guangdong Pharmaceutical University was selected as the study subjects, which had adopted the nosocomial infection informatics surveillance system since Jan.2020. The period of Jan.to Dec.2020 were regarded as the study period, and Jan.to Dec.2019 were regarded as the control period. The situation of nosocomial infection and MDROs infections in the two periods were retrospectively analyzed. RESULTS: The incidence of nosocomial infections and underreporting of nosocomial infection cases in this hospital during the study period were 2.52%(1 325/52 624) and 1.74%(23/1 325), respectively, and the incidences of ventilator associated pneumonia(VAP), catheter related bloodstream infection(CRBSI), catheter related urinary tract infection(CAUTI)were 4.10(31/7 568), 2.11(14/6 634), and 2.50(25/9 993) respectively, which were lower than those during the control period(P< 0.05). The positive rate of pathogenic examination in the hospital during the study period was 77.95%(1 269/1 628), which was higher than that during the control period(P<0.05), the overall detection rate of MDROs was 15.77%(206/1 306), the detection rates of MDROs in Escherichia coli, Acinetobacter baumannii, Klebsiella pneumoniae, Staphylococcus epidermidis, Pseudomonas aeruginosa and Staphylococcus aureus were lower than those during the control period(P<0.05). CONCLUSION: The development and application of the informatics technology-based surveillance system of nosocomial infection could effectively reduce the incidence of nosocomial infections and device related infections, decrease the under-reporting of infection cases, and also reduce the detection rate of MDROs as well as the proportion of MDROs detected in common pathogenic species.

Analysis of pathogen detection results of upper respiratory tract specimens from fever clinic patients

Objective: To explore the pathogen composition and distribution characteristics of pathogens in respiratory samples from patients with fever of unknown origin. Methods: A total of 96 respiratory samples of patients with unknown cause fever with respiratory symptoms were collected from four hospitals above grade II in Shijiazhuang area (Hebei Provincial Hospital of Traditional Chinese Medicine, Luancheng District People's Hospital, Luquan District People's Hospital, Shenze County Hospital) from January to April 2020, and multiplex-fluorescent polymerase chain reaction(PCR)was used to detect influenza A virus, influenza B virus, enterovirus, parainfluenza virus I/II/III/IV, respiratory adenovirus, human metapneumovirus, respiratory syncytial virus, human rhinovirus, human bocavirus, COVID-19, Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumophila, Pseudomonas aeruginosa, Streptococcus pneumoniae, Klebsiella pneumoniae, Group A streptococcus, Haemophilus influenzae, Staphylococcus aureus nucleic acid detection, the results were analyzed for chi-square. Results: A total of 8 pathogens were detected in the upper respiratory tract samples of 96 fever patients, including 1 kind of virus, 6 kinds of bacterias, and Mycoplasma pneumoniae. There were 12 viruses including influenza virus and parainfluenza virus, Legionella pneumophila and Chlamydia pneumoniae were not detected. The pathogen detection rates in descending order were Streptococcus pneumoniae (58/96, 60.42%), Haemophilus influenzae(38/96, 39.58%), Klebsiella pneumoniae (14/96, 14.58%), Staphylococcus aureus (10/96, 10.42%), Mycoplasma pneumoniae (8/96, 8.33%), Pseudomonas aeruginosa (6/96, 6.25%), Group A streptococcus (4/96, 4.17%) and human rhinovirus (2/96, 2.08%). The proportions of single-pathogen infection and multi-pathogen mixed infection in fever clinic patients were similar, 41.67% (40/96) and 45.83% (44/96), respectively, and 12.50% (12/96)of the cases had no pathogens detected. The infection rate of Mycoplasma pneumoniae in female patients with fever (21.43%) was higher than that in male patients with fever (2.94%) (P < 0.05). There was no statistical difference between the distribution of of other pathogens and gender and age(P > 0.05). Conclusions: The upper respiratory tract pathogens were mainly bacterial infections, and occasional human rhinovirus and Mycoplasma pneumonia infections. In clinical diagnosis and treatment, comprehensive consideration should be given to the pathogen detection.

Face masks as sources of cross-contamination during food preparation

Amid the COVID-19 pandemic, mask-wearing has become a common practice in the foodservice industry to prevent the spread of respiratory diseases. Like kitchen utensils, a mask may serve as a vehicle for cross-contamination of pathogens during food handling. The objective of this study was to quantify cross-contamination between tasks of handling contaminated chicken and chopping lettuce. Chicken breasts were inoculated with a high or a low level of nonpathogenic Escherichia coli surrogates (ca. 6 or 4 log CFU/ml) and sliced for 1, 5, or 10 min. During slicing, duplicate, single-use medical masks were touched each minute. One mask was immediately sampled, but the second mask was used to contaminate lettuce by touching the mask each minute while chopping the lettuce for 5 min. E. coli were enumerated from the second mask and lettuce. Masks touched while slicing both high- and low-inoculated chicken showed significant contamination (0.8-4.9 log CFU/cm2) after each slicing scenario of 1, 5, or 10 min (P > 0.05). Lettuce was significantly contaminated regardless of inoculation level (1.0-3.2 log CFU/g). Slicing time was a significant factor in some cases (P < 0.05), whereas inoculation level was not (P > 0.05). Data indicate masks can be a source of cross-contamination if not replaced appropriately.

Molecular investigation of Campylobacter spp. and Salmonella infection in children with community acquired diarrhea

Introduction : Acute gastroenteritis is a typical disorder that accounts for 8-12% of pediatric outpatient visits. Campylobacter and Salmonella infections account for about 8.4% and 11% of global diarrhea cases. Due to the importance of these bacteria in pediatric diseases, the aim of this study was to determine the infectious rate of Salmonella and Campylobacter species and also the frequency of the gene encoding Cytholethal distending toxin in children with community-acquired diarrhea. Materials and Methods: Stool samples of children under 5 years of age with diarrhea were collected. The samples were related to children referred to hospitals in Hamadan, Ardabil, Bandar Abbas and two hospitals in Tehran. DNA was extracted from the samples using a DNA extraction kit from stool. The presence of Campylobacter in the studied samples was detected by polymerase chain reaction using specific primers. A control stool sample was spiked with 10-fold dilution of C. jejuni suspension for LOD (detection limit determination) measurement. Results: In this study, PCR results showed a LOD of 100 CFU per gram in the spiked feces sample. Accordingly, out of 144 fecal samples of children with acute diarrhea, one case was positive for Campylobacter jejuni;this sample was also positive for the presence of cdtB gene. Presence of Salmonella was confirmed in two samples of the patients (1.4%). Conclusion: Low prevalence of Campylobacter and Salmonella was detected in symptomatic children under 5 years of age during the Covid-19 pandemic. Examination of these samples for viruses and other microbial agents can clarify the etiology of diarrhea in children referred to the hospitals.

Evaluation of expression and titration of recombinant nucleocapsid protein as an immunogenic candidate against SARS-CoV2

Introduction: Covid-19 epidemic results from an infection caused by SARS-CoV2. Evolution-based analyses on the nucleotide sequences show that SARS-CoV2 is a member of the genus Beta-coronaviruses and its genome consists of a single-stranded RNA, encoding 16 proteins. Among the structural proteins, the nucleocapsid is the most abundant protein in virus structure, highly immunogenic, with sequence conservatory. Due to a large number of mutations in the spike protein, the aim of this study was to investigate bioinformatics, expression of nucleocapsid protein and evaluate its immunogenicity as an immunogenic candidate. Materials and Methods: B and T cell epitopes of nucleocapsid protein were examined in the IEDB database. The PET28a-N plasmid was transferred to E. coli BL21(DE3) expression host, and IPTG induced recombinant protein expression. The protein was purified using Ni-NTA column affinity chromatography, and the Western blotting method was utilized to confirm it. Finally, mice were immunized with three routes of purified protein. Statistical analysis of the control group injection and test results was carried out by t-test from SPSS software. Results: The optimized gene had a Codon adaptation index (CAI) of 0/97 Percentage of codons having high- frequency distribution was improved to 85%. Expression of recombinant protein in E. coli led to the production of BoNT/B-HCC with a molecular weight of 45 kDa. The total yield of purified protein was 43 mg/L. Immunization of mice induced serum antibody response. Statistical analysis showed that the antibody titer ratio was significantly different compared to the control sample and the antibody titer was acceptable up to a dilution of 1.256000. Conclusion: According to the present study results, the protein can be used as an immunogenic candidate for developing vaccines against SARS-CoV2 in future research.

19th Seminar on Tropical Pathology and Public Health 12th Biotechnology Week 1st Physical Therapy Week, Virtual, 23-25 November 2022

These proceedings comprise 85 articles spanning diverse fields such as bacteriology, molecular biology, biotechnology, dermatology, infectious and parasitic diseases, epidemiology, physiotherapy, immunology, mycology, parasitology, pathology, collective health, and virology. The articles delve into a wide range of research topics, from repurposing drugs for Mycobacterium abscessus complex infections to utilising artificial intelligence for SARS-CoV-2 diagnosis. In bacteriology, investigations explore the correlation between smoking and Helicobacter pylori infection in gastric adenocarcinoma patients, as well as the resistance profiles of Staphylococcus aureus and Pseudomonas aeruginosa in tracheostomised children. Molecular biology studies focus on gene polymorphisms related to diseases like paracoccidioidomycosis. Biotechnology research emphasises bioactive molecules in species like Croton urucurana and the development of computational models for cytotoxicity prediction. Dermatology articles address stability characterisation in vegetable oil-based nanoemulsions. The section on infectious and parasitic diseases encompasses studies on COVID-19 vaccine response in pregnant women and the impact of infection prevention measures in rehabilitation hospitals. Epidemiology investigations analyse trends in premature mortality, tuberculosis in diabetic patients, and public adherence to non-pharmacological COVID-19 measures. Physiotherapy research covers topics such as telerehabilitation through a developed game and the prevalence of congenital anomalies. Immunology studies explore immune responses in HIV and Leishmaniasis, whilst mycology investigates the biotechnological potential of fungi from the cerrado biome. Parasitology research evaluates treatment efficacy against vectors parasites such as Aedes aegypti and Toxoplasma gondii. Pathology articles discuss intentional intoxication in cattle and the influence of curcumin on acute kidney injury therapy. Collective health studies focus on intervention plan development in healthcare settings and pesticide use in horticulture. Lastly, virology research investigates parvovirus occurrence in hospitalised children during the COVID-19 pandemic, hidden hepatitis B virus infection in inmates, and the prevalence of HPV and HTLV-1/2 infections in specific populations.

Establishment and applications of a duplex quantitative real-time RT-PCR assay for simultaneous detection of bovine rhinitis A virus and bovine rhinitis B virus

Bovine rhinitis virus (BRV) is an important pathogen responsible for the bovine respiratory disease complex (BRDC) and can be divided into two genotypes (BRAV and BRBV). To establish a duplex quantitative real-time RT-PCR assay for simultaneous detection of BRAV and BRBV, specific primers and TaqMan probes targeting the 5'NTR of BRAV and 3'NTR of BRBV were designed. A duplex quantitative real- time RT- PCR assay for simultaneous detecting BRAV and BRBV was preliminarily established by optimizing reaction conditions for each step. The assay specifically detects BRAV and BRBV, and no crossreaction with other common bovine respiratory pathogens, including IDV, BCoV, BVDV-1, BRSV, BPIV-3, BAdV-3, mycoplasma bovis, Pasteurella multocida, Mannheimia haemolytica, Escherichia coli, and Salmonella, was observed. In addition, the sensitivity test showed that the detection limits of this assay were 3.2x101 copies/L for both BRAV and BRBV plasmid standards. Besides, the repeatability test showed that the variation coefficients of this assay were less than 0.05 from both lot-to-lot and intra-lot. These results showed that the assay has high specificity, extreme sensitivity, and good repeatability. Moreover, a total of 43 nasal swabs of BRDC cattle were tested by our assay and four other quantitative real-time RT-PCR assays, including 3 BRAV assays and 4 BRBV assays. The results showed that the detection rates of our assay were 32.56%(14/43) for BRAV and 30.23%(13/43) for BRBV, and the detection rates of other quantitative real-time RT-PCR assays were 0(0/43), 2.33%(1/43), 23.26%(10/43) for BRAV and 27.91% (12/43), 27.91%(12/43), 27.91%(12/43), 27.91%(12/43) for BRBV, indicating that our assay has a more substantial detection capability than other assays. This study firstly established a duplex quantitative real-time RT-PCR assay for simultaneous detection of BRAV and BRBV, and the assay exhibited high specificity, sensitivity, and stability. Moreover, the study firstly confirmed the existence of BRAV in China, contributing to the prevention and control of BRDC.

Distribution and drug resistance analysis of pathogenic bacteria in a hospital blood culture, 2018-2022

Objective: To analyze the distribution and drug resistance of pathogenic bacteria in blood culture specimens of patients with bloodstream infections before and after COVID-19 (2018-2019 and 2020-2021), and to provide scientific basis and reference for rational treatment and effective control of bloodstream infections in the post-epidemic period. Methods: Blood culture specimens were collected from patients in Zhongnan Hospital of Wuhan University in the two years before and after the COVID-19 outbreak (2018-2021). The Automated Blood Culture Systems were used to perform blood culture on blood specimens sent for clinical inspection, and the Vitek MS automatic bacterial identification mass spectrometer was used for strain identification and the Vitek 2 automatic bacterial drug susceptibility analyzer was used for drug susceptibility testing and drug resistance analysis. Results: Blood culture specimens were performed on 28 736 patients with suspected bloodstream infection submitted for inspection from January 2018 to December 2019, and a total of 2 181 strains of pathogenic bacteria were detected after removing duplicate strains, with a positive rate of 7.69%, including 1 046 strains of Gram-negative bacteria, accounting for 47.96%. From January 2020 to December 2021, blood culture specimens from 26 083 patients with suspected bloodstream infection were submitted for inspection, and a total of 2 111 strains of pathogenic bacteria were detected after excluding duplicate strains, with a positive rate of 8.09%, including 1 000 strains of Gram-negative bacteria accounted for 47.37%. The drug resistance of Klebsiella pneumoniae was relatively serious, and the sensitivity rate to ertapenem, polymyxin B and tigecycline was more than 90%. The main non-fermentative bacteria Acinetobacter baumannii was more than 50% sensitive to piperacillin/tazobactam, amikacin and polymyxin B. The sensitivity rates of Pseudomonas aeruginosa to piperacillin/tazobactam, ceftazidime, cefepime, amikacin, gentamicin, tobramycin, ciprofloxacin, levofloxacin, piperacillin and meropenem were more than 50%. Conclusions: In the two years before and after COVID-19, there are many types of pathogenic bacteria in bloodstream infection, but the distribution do not differ significantly. The pathogens of bloodstream infection are mainly distributed in ICU, hepatobiliary research institute, and nephrology department. Among them, Gram-negative bacteria such as Escherichia coli, Klebsiella pneumoniae and Acinetobacter baumannii are the main ones, and different pathogens showed great differences in drug resistance.

Single center retrospective study on the distribution of pathogens in elderly patients with acute exacerbation of chronic obstructive pulmonary disease

Objective: To explore the distribution and correlation of pathogens in the elderly patients with AECOPD, so as to guide the rational use of antibiotics and hormones in clinic. Methods: A total of 111 patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) admitted to Nanjing First Hospital from January 2019 to January 2020 were retrospectively analyzed. The basic data such as eosinophil, neutrophil and lymphocyte count, the levels of C-reactive protein(CRP) and erythrocyte sedimentation rate (ESR)in blood routine examination were collected. Further, the pathogens were qualified by sputum fluorescence quantitative polymerase chain reaction, and the pathogens distribution was analyzed. Results: The level of ESR and the ratio of cardiovascular diseases showed significant differences between the pathogen-positive group and pathogen-negative group. In this study, the top five pathogens in AECOPD patients were EB virus (21.6%), Haemophilus influenzae (19.8%), Streptococcus pneumoniae (17.1%), herpes simplex virus(14.4%), influenza A virus(14.4%). The detection rate of influenza A virus was correlated with influenza B virus and Aspergillus (P < 0.05);The detection rate of respiratory syncytial virus was correlated with Candida, Moraxella catarrholis, Streptococcus pneumoniae and Haemophilus influenzae (P < 0.05);The detection rate of Escherichia coli was correlated with rhinovirus, adenovirus, Klebsiella pneumoniae and Acinetobacter baumannii (P < 0.05);The detection rate of Candida was correlated with that of Moraxella catarrholis and Pseudomonas aeruginosa(P<0.05);The detection rate of human coronavirus was correlated with Haemophilus influenzae, herpes simplex virus and Streptococcus pneumoniae(P < 0.05). Conclusions: AECOPD are mostly induced by different pathogens, especially mixed infection of bacteria and virus. It is helpful to guide the rational use of antibiotics by analyzing the etiological characteristics in the elderly patients with AECOPD.

Coinfection in the cases of feline panleukopenia: a literature review

Coinfection caused by bacteria, parasites, or viruses complicates almost all feline panleukopenia virus (FPV) infections. Pathogens that colonize the gastrointestinal tract, Clostridium perfingens, Clostridium piliforme, Cryptosporidium spp, Giardia spp, Tritrichomonas fetus, canine parvovirus type 2,Salmonella sp., feline coronavirus, feline bocavirus, and feline astrovirus were isolated in the presence of FPV infection. Complex mechanisms between viruses, bacteria, protozoa, and hosts contribute to the pathogenesis and severity of coinfection. Prompt and accurate diagnosis, vaccination precautions, and appropriate treatment play important roles in reducing morbidity and mortality. This article outlines the etiology, pathogenesis, diagnosis, prevention, and treatment that can help veterinarians and pet owners improve their knowledge of managing the diseases.

Infectious disease Roundup 2022

This paper describes the epidemiology, prevalence, transmission, prevention and control of some infectious diseases in companion animals, livestock, wild animals and humans in Ontario, Canada, in 2022, including SARS-CoV-2;Echinococcus multilocularis, Leishmania spp. and SARS-CoV-2;antimicrobial stewardship resources;2 cases of rabid dogs imported from Iran (July 2021 and January 2022);prevalence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriacea, Dirofilaria immitis, Brucella canis, canine parainfluenza and adeno- and herpes viruses in dogs recently imported from Asia;Paragonimus kellicotti lung flukes and Streptococcus equi subsp. zooepidemicus in dogs;African swine fever in pet pigs, backyard pigs and wild pigs and blastomycosis in dogs and humans.

Summary of global surveillance data of infectious diseases in January 2023

In January 2023, a total of 64 infectious diseases were reported globally, affecting 235 countries and regions. Except for influenza, the top five infectious diseases affecting greatest number of countries and regions were COVID-19 (235), monkeypox (110), dengue fever (31), measles (27) and cholera (15). The top five infectious diseases with highest case fatality rates were Nipah virus disease (62.5%), Ebola virus disease (47.0%), Crimean-Congo haemorrhagic fever (37.5%), Lassa fever (15.1%) and West Nile fever (7.6%). The top five infectious diseases with greatest number of deaths were COVID-19, malaria, cholera, measles and dengue fever. The prevalent infectious diseases in Asia were COVID-19, cholera and dengue fever, the prevalent infectious diseases in Africa were COVID-19, cholera, yellow fever, Lassa fever, malaria and monkeypox, the prevalent infectious diseases in America were COVID-19, cholera, monkeypox, dengue fever and chikungunya fever, the prevalent infectious disease in Europe were COVID-19, monkeypox and invasive group A streptococcus infection.

Evaluation and analysis of rates of bacterial co-infections and antimicrobial usage in COVID-19 patients: a retrospective cohort analysis

Background: The coronavirus disease 2019 (COVID- 19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread over the world. Although there are minimal microbiological and antibiotic data on COVID-19, bacterial co-infections have been related to poor outcomes in respiratory viralinfections. Adequate antibiotic use in conformity withantibiotic stewardship (ABS) recommendations is necessary during the pandemic. Material and procedure: We conducted a retrospective single-center cohort analysis of 140 adulthospitalised patients (ages 17-99) with confirmed COVID-19 who were admitted between February 16, 2021, and April 22, 2021, and who were discharged onMay 6, 2021. From 140 COVID-19 participants, the following clinical data was gathered: Men made up 63.5 percent of the participants, with a median age of 63.5 years (range 17-99). Results: According to local ABS recommendations, the most commonly administered antibiotic regimen was ampicillin/sulbactam (41.5 percent) with a median length of 6 (range 1-13) days. Urine antigen testing for Legionella pneumophila and Streptococcus peumoniaewas negative in all of the patients. In critically ill patients hospitalised to intensive care units (n = 50), co-infections with Enterobacterales (34.0%) and Aspergillus fumigatus (18.0%) were discovered. Blood cultures obtained at admission had a diagnostic yield of 4.2 percent. Conclusion: While bacterial and fungal co-infections are rare in COVID-19 patients, they are widespread in critically ill individuals. More investigation into the impact of antimicrobial therapy on therapeutic success in COVID-19 patients is essential to prevent antibiotic abuse. COVID-19 management might be improved with the aid of ABS standards. It's also necessary to look at the microbiological patterns of infectious consequences in COVID-19 individuals who are severely unwell.

Preventive measures for managing Legionella in drinking water systems during epidemics

This paper describes and summarizes the strategies and measures that should be applied in Croatia to prevent Legionella contamination in drinking water systems in buildings during the COVID-19 epidemic. Legionella colonisation in drinking water installations increases the risk of infection for humans and it is important to point out that this public health problem is even greater during other epidemics. Legionella can cause very severe types of pneumonia called Legionnaires' disease and less serious illness Pontiac fever. Therefore, Croatia will implement the new EU Directive 2020/2184 on the quality of water intended for human consumption into its legislation, which for the first time includes an obligation to assess the risk of Legionella. This should help reduce the health risk or complications of respiratory infections (severe pneumonia) and mortality during other epidemics (COVID-19 and similar).

Summary of global surveillance data of infectious diseases in December 2022

In December 2022, a total of 68 infectious diseases were reported globally, affecting 235 countries and regions. Except for influenza, the top five infectious diseases affecting greatest number of countries and regions were COVID-19 (235), monkeypox (110), dengue fever (28), measles (27) and cholera (14). The top five infectious diseases with highest case fatality rates were Ebola virus disease (47.0%), Rift Valley fever (44.2%), Crimean-Congo haemorrhagic fever (40.0%), Lassa fever (17.6%) and West Nile fever (7.6%). The top five infectious diseases with greatest number of deaths were COVID-19, malaria, cholera, dengue fever and measles. The prevalent infectious diseases in Asia were COVID-19, cholera and dengue fever, the prevalent infectious diseases in Africa were COVID-19, cholera, yellow fever, Lassa fever, monkeypox, malaria and measles, the prevalent infectious diseases in America were COVID-19, cholera, monkeypox, dengue fever and chikungunya fever, the prevalent infectious disease in Europe were COVID-19, monkeypox and invasive group A streptococcus infection.

Possession of exotic animals and zoonotic diseases: an approach from the Mexican context

The possession of exotic animals as pets is a social practice that has become more visible in Mexico in recent years, so it is interesting to understand its environmental and social implications and those related to human health. The present study aims to identify the main species of exotic animals kept as pets and the zoonotic diseases reported in these species. We analyzed official figures of seizures of exotic fauna in Mexico and reviewed specialized literature on zoonotic diseases documented in Mexico in these species. We identified zoonoses in species of fauna that can be acquired legally and illegally in the country, reported in environments in which animals coexist with other species and are in direct contact with people, which represents an important factor in the spread and propensity of this type of disease. We conclude that the sanitary regulation of wildlife markets, the monitoring and studying microorganisms associated with wildlife are valuable strategies to prevent the emergence of zoonoses.

Truncated expression of S1 protein of Feline infectious peritonitis virus and preparation of its monoclonal antibody

In order to develop monoclonal antibody against Feline infectious peritonitis virus (FIPV) S1 protein, the truncated S1 protein (rS1) was expressed through Escherichia coli and subsequently purified. Then BALB/c mice were immunized with purified rSl. Three hybridoma cell strains, named 2D7,3D8 and 5G1, stably secreting antibodies against rSl were obtained by cell fusion and indirect ELISA screening. The identification of antibody subtype showed that antibody subtypes of 2D7,5G1 and 3d8 strains were IgG2a,IgG2a and IgGl,respectively. And the light chain of those three hybridoma cell strains was Kappa. Result of karyotype identification of hybridoma cells showed that the chromosome numbers of those three hybridoma cells were about 102,101 and 103, which was belonged to the karyotype of hybridoma. The titer of ascites antibody for indirect ELISA was 1 : 204 800, and monoclonal antibodies were purified. Moreover, all of 2D7,3D8 and 5G1 could react with rS1 by Western-blot and FIPV in cells by IFA. These data suggest that three monoclonal antibodies against rSl with good activities were ideal materials in the study of early diagnosis of FIPV and the biological function of FIPV in the future.

Differentiating infectious from non-infectious respiratory disease in the cat and dog

This paper describes the clinical signs and use of differential laboratory diagnostic techniques (computed tomography, cytology, histopathology, antigen/antibody detection and polymerase chain reaction) for infectious (viral, bacterial, fungal and parasitic) and non-infectious (inflammatory/immune mediated, neoplastic, cardiac, malformation, foreign body, smoke inhalation, aspiration of caustic material, non-cardiogenic, pulmonary oedema, traumativ, pneumothorax, pulmonary contusions and idiopathic) causes of respiratory diseases in cats and dogs in Ontario, Canada.

One-step multiple TaqMan real-time RT-PCR for simultaneous detection of swine diarrhea viruses

Objective: The aim of this study was to establish a one-step multiplex real-time RT-PCR method to simultaneously detect and quantify five swine diarrhea related viruses, PEDV, GARV, PDCoV, SADS-CoV and PTV, so as to provide an efficient and sensitive tool for rapid diagnosis and epidemiological investigation of porcine diarrhea. Method: The ORF3 gene sequences of several genotypes of PEDV were analyzed, and then the primers and probes were designed for detection of PEDV field strains by referring to the ORF3 genes, which contained deletion mutations in attenuated strains. The 5'-end conserved region of NSP5 genes of GARV G3, G4, G5 and G9 strains were analyzed for design of probes and primers. The specific primers and probes targeting to the conserved regions of PDCoV M, PTV 5'UTR and SADS-CoV N genes were designed for detection of the pathogens. The ROC curves were completed by referring to parameters that were set in RStudio. The specificity value, sensitivity value, and areas under the curves (AUC) and Youden value were calculated according to ROC curves to determine the cut-off CT value. The amplified fragments were cloned into pEASY-T1 vector. The standards prepared through in vitro transcription were named as cRNA-PEDV, cRNA-GARV, cRNA-PDCoV, cRNA-PTV and cRNA-SADS-CoV. The sensitivity, specificity and repeatability of one-step multiplex real-time RT-PCR were evaluated. Coincidence rate between this and another similar method were compared in the detection of clinical samples. Result: Both the annealing temperature and optimal concentrations of primers and probes were obtained for detection of the five pathogens. According to the ROC curve, the CT cut off values for detection of PEDV, GARV, PDCoV, PTV, and SADS-CoV were set as 35.78, 34.25, 34.98, 34.60, and 35.70, respectively. The detection sensitivity of this method for the five pathogens could reach 1..102 copies/L. The standard curves had a good linear relationship and the amplification efficiency was between 96.3% and 104%. The established method could not detect the PEDV vaccine strains and other swine infecting viruses and bacteria including TGEV, CSFV, PRV, PRRSV, S.choleraesuis, P.multocida, E.coli, S.suis and S.aureus. The repeatability test showed the range of intra-assay and inter-assay coefficients of variability: 0.22% to 3.08% and 0.89% to 4.0%, respectively. The detection coincidence rates of the established detection method and another similar method for the five pathogens in 242 clinical samples were 97.9%, 98.8%, 100%, 98.3% and 100% for PEDV, GARV, PDCoV, PTV and SADS-CoV, respectively. The Kappa values were all higher than 0.9. The method had advantage over a commercial diagnostic kit for detection of PEDV wild strains in accuracy. Detection results with clinical samples showed that positive rates of PEDV, GARV, PDCoV and PTV was 10.7% (26/242), 13.6% (33/242), 18.2% (44/242) and 14.5% (35/242), respectively, demonstrating the prevalence state of the four pathogens in Sichuan province in the years. SADS-CoV was not detectable in any areas, but the phenomenon of coinfection with different diarrhea causing viruses was common. Therefore, it was necessary to strengthen the surveillance of several porcine diarrhea viruses in Sichuan province for preventive control. Conclusion: In this study, a one-step multiplex real-time RT-PCR was established for simultaneous detection of PEDV wild strains, PDCoV, SADS-COV and GARV, PTV multiple genotypes, which provided an efficient and sensitive tool for the differential diagnosis and epidemiological investigation of swine diarrhea disease.

Thyroid outbreak during the pandemic of COVID-19: a report

Background : In the 19th Week of 2020, Integrated Disease Surveillance Programme (IDSP) noted an unusual increase in the number of fever cases in Routine Syndromic Surveillance. Objectives : The unusual increase of fever cases were investigated to identify the agent, the source of infection and to propose recommendations for control measures. Methods : Active surveillance of fever cases done, blood samples, stool samples and water samples were collected from the affected area. The secondary data of indoor and outdoor patient were collected from the nearest health facilities. Result : It was a single peak outbreak of typhoid, started from 1st May, 2020, had peaked during the 19th Week of May. 2020 and ended on 31st May, 2020. The epicentre of the outbreak was the residential colony of Industrial labour. The outbreak of Typhoid occurred due to conditions generated due to the pandemic of COVID -19. Two sources of active infection were found. First, contaminated supply of drinking water and second a food-handler, who was the carrier of Typhoid. Interpretation and Conclusion : It is a lesson to learn that the local communicable diseases should be monitor during the pandemic. Otherwise, that can cause the situation of co-epidemic.