A retrospective analysis on seroprevalence of acute viral hepatitis observed among dengue patients attending a tertiary care centre in central India

PURPOSE

The present study was conducted retrospectively to assess the frequency of acute viral hepatitis among the clinically suspected dengue cases presented at our tertiary care centre during 2021.

METHODS

To determine the presence of acute viral hepatitis; Hepatitis A virus (HAV) and Hepatitis E virus (HEV) infections, 104 specimens were selected from the dengue-suspected clinical specimens received during 2021 on the basis of acute viral hepatitis symptoms. Following this, serological diagnosis was performed on those samples using anti-HAV IgM and anti-HEV IgM ELISA kits.

RESULTS

Based on sero-positivity for IgM antibodies, 3 (5.3%) dengue virus (DENV) seropositive samples were positive for both HAV and HEV, while among DENV seronegative cases, 11 (22.91%) samples were positive for HEV and 1 (2.08%) sample was positive for HAV, pointing towards misdiagnosis due to overlapping symptoms. Additionally, co-infection of HAV & HEV in 1 sample was also observed in this study.

CONCLUSIONS

This study revealed the presence of acute hepatitis infections among the dengue cases during monsoon and post-monsoon season. Overlapping of the clinical manifestations of these diseases can create misdiagnosis incidences raising risk for underreporting of the true cases of acute viral hepatitis infection. Dengue-suspected patients with selected symptoms during the monsoon and post-monsoon season should additionally be screened for acute hepatitis infections, as suggested in this study.

Performance Evaluation of Different RT-PCR Kits for the Direct Detection of SARS-CoV-2 in Preheated Specimens

Background  Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has created high demand for molecular kits and consumables for mass screening of suspected individuals. Direct real-time polymerase chain reaction (RT-PCR) assay without nucleic acid extraction has several advantages in saving testing time and cost and helps in the rapid reporting of SARS-CoV-2. The present study evaluated the analytical performance of four SARS-CoV-2 RT-PCR for direct RT-PCR testing using preheated specimens. Methods  A total of 100 clinical specimens were selected and divided into three different groups: (1) group I: 20 SARS-CoV-2 positive specimens with high viral load, viz., low Ct values (< 30 Ct), (2) group II: 50 SARS-CoV-2 positive specimens with low viral load, viz., high Ct values (> 30 Ct), and (3) group III: 30 SARS-CoV-2 negative specimens. Specimens were heat-inactivated at 70°C for 10 minutes and cooled down at 4°C and were evaluated for standard and direct RT-PCR method by using ViralDtect-II Multiplex Real-Time PCR kit, TaqPath COVID-19 Combo kit, COVIDsure Pro Multiplex RT-PCR kit, and Hi-PCR Coronavirus (COVID-19) Multiplex Probe PCR kit. Results  Results showed that except ViralDtect-II kit, the other three TaqPath COVID-19 Combo kit, COVIDsure Pro kit, and Hi-PCR Coronavirus (COVID-19) RT-PCR kit were able to amplify all the SARS-CoV-2 genes in the direct RT-PCR method using preheated specimens. In group I specimens, 100% sensitivity was observed in all three RT-PCR kits. In group II specimens, COVIDsure Pro kit was found to be superior among other kits. Conclusion  Direct RT-PCR method during pandemic situation is valuable and cost effective for the detection of SARS-CoV-2. All three TaqPath COVID-19 Combo kit, COVIDsure Pro kit, and Hi-PCR Coronavirus (COVID-19) RT-PCR kit can be used for direct RT-PCR method and COVIDsure Pro kit performance was found to be superior among all.

Emergence of Multidrug-Resistant Non-Fermenting Gram-Negative Bacilli in a Tertiary Care Teaching Hospital of Central India: Is Colistin Resistance Still a Distant Threat?

Purpose Multidrug-resistant (MDR) organisms are being increasingly reported from India. This study aimed to determine the antibiotic susceptibility pattern of non-fermenting Gram-negative bacilli (NF-GNB) isolated from all the clinical samples to estimate the prevalence of MDR MDR NF-GNB and to screen for colistin-resistance genes among all colistin-resistant strains. Materials and methods This prospective study conducted from January 2021 to July 2022 at a tertiary care teaching hospital in central India identified MDR NF-GNB from clinical samples using standard procedures and antimicrobial susceptibility testing conducted as per Clinical Laboratory Standards Institute (CLSI) guidelines. Colistin-resistant strains identified by broth microdilution were further subjected to detection of plasmid-mediated colistin-resistant genes (mcr-1, mcr-2, mcr-3) by polymerase chain reaction (PCR). Results A total 2,106 NF-GNB were isolated from 21,019 culture positive clinical samples, of which 743 (35%) were MDR. Majority of MDR NF-GNB isolated were from pus (45.50%) followed by blood (20.50%). Out of 743 non-duplicate MDR non-fermenters,the most common were Pseudomonas aeruginosa (51.7%), Acinetobacter baumannii (23.4%),and others (24.9%).Around5.2% Pseudomonas aeruginosa and 2.3% Acinetobacter baumannii were resistant to colistin, and 88.2% were resistant to ceftazidime. Burkholderia cepacia complexwas 100% susceptible to minocycline and least susceptible to ceftazidime (28.6%). Out of 11, 10 (90.9%) Stenotrophomonas maltophilia were susceptible to colistin and least susceptible to ceftazidime and minocycline (27.3%). All 33 colistin-resistant strains (minimal inhibitory concentration ≥ 4 µg/mL) were found to be negative for mcr-1, mcr-2, and mcr-3 genes. Conclusion Our study showed a significantly wide variety of NF-GNB, ranging from Pseudomonas aeruginosa (51.7%), Acinetobacter baumannii (23.4%),to Acinetobacter haemolyticus (4.6%), Pseudomonas putida (0.9%), Elizabethkingia meningoseptica (0.7%), Pseudomonas luteola (0.5%), and Ralstonia pickettii (0.4%), which have not been commonly reported in literature. Of all the non-fermenters isolated in the present study, 35.28% were MDR, raising the concern for rationalizing antibiotic use and improving infection control measures to avert or slow the emergence of antibiotic resistance.

Incidence of Non Amplification of N Gene of SARS-CoV-2 using Commercially Available Real Time Polymerase Chain Reaction Kit and its Comparison with Two Other Different Kits

Introduction: Novel Coronavirus Disease 2019 (COVID-19) caused by the Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) has resulted in an unprecedented global pandemic. Real Time Polymerase Chain Reaction (RT-PCR) tests are being used in the diagnosis of COVID-19 worldwide however mutations in the SARS-CoV-2 genome have generated many SARS-CoV-2 genome variants and which may affect the correct Reverse transcriptase-Real time Polymerase Chain Reaction (RT-PCR) diagnosis. Aim: To confirm and study the incidence of the non amplification of the SARS-CoV-2 Nucleocapsid gene (N gene) target among known SARS-CoV-2 positive samples. Materials and Methods: This retrospective observational study was carried out at the State Virology Laboratory, Gandhi Medical College, Bhopal, Madhya Pradesh, India during January 2021 to May 2021. During the study period, a total of 159 SARS-CoV-2 positive samples were failed to amplify the N gene target. To investigate the non amplification of N gene target of SARSCoV-2, a total of 20 samples were selected and retested using the initially used RT-PCR kit (VIRALDTECT RT-PCR kit) and also with the two different RT-PCR kits (TaqPath RT-PCR kit and Hi-PCR RT-PCR kit) which also contain primers/probes for the SARS-CoV-2 N gene target. Results: Amplification and detection of the SARS-CoV-2 N target gene was not observed in VIRALDTECT RT-PCR test results. In contrast, amplification was detected in the N gene target of SARS-CoV-2 while using the TaqPath and Hi-PCR kits. Obtained results confirm the failure of the annealing of VIRALDTECT kit N gene primer/probe and suggest the possible mutation event in the SARS-CoV-2 N gene among the N gene non amplified samples. Conclusion: Present study reports, the incidence of non amplification of SARS-CoV-2 N gene, where the RT-PCR kit failed to detect N gene target and seriously affect RT-PCR diagnosis. Hence, the study emphasises the revalidation of commercially available SARS-CoV-2, RT-PCR kits to identify these kinds of failure incidence.

Stability of SARS-CoV-2 RNA in Viral Lysis Buffer Stored at Different Temperatures

Objectives  The present COVID-19 pandemic resulted in an increased need for molecular diagnostic testing. Delay in the specimen processing and suboptimal storage of suspected samples in laboratories leads to degradation of SARS-CoV-2 viral RNA. Viral lysis buffers from RNA extraction kits have the potential to stabilize RNA. Hence, this study aimed to investigate the stability of SARS-CoV-2 RNA in viral lysis buffer at different temperatures and time periods.

Materials and Methods  Aliquots of samples with known SARS-CoV-2 RNA were processed in viral lysis buffers simultaneously, stored separately at 2 to 8°C and 22 to 28°C for 24 hours, 48 hours and 72 hours. SARS-CoV-2 viral RNA was extracted from each aliquot and analyzed using multiplex real-time PCR.

Results  SARS-CoV-2 RNA in samples placed in viral lysis buffer was stable for 48 hours at both 2 to 8°C and 22 to 28°C temperatures. Slight decline in the viral RNA quantity was found on aliquots tested after 48 hours of both the temperatures.

Conclusions  Viral lysis buffer maintains the integrity of SARS-CoV-2 RNA for up to 48 hours even at room temperature and supports delayed diagnosis with an overwhelming sample load in testing laboratories.

Investigation of Different Commercially Available Real Time-Polymerase Chain Reaction Kits for SARS-CoV-2 Diagnosis

Introduction: The whole world is facing an ongoing global health emergency of COVID-19 disease caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). Real-Time Reverse Transcription-Polymerase Chain Reaction (RT-PCR) is a gold standard in the detection of SARS-CoV-2 infection. Presently, many single tube multiple gene target RT-PCR kits have been developed and are commercially available for Coronavirus Disease 2019 (COVID-19) diagnosis. Aim: To evaluate the performance of seven COVID-19 RT-PCR kits (DiagSure, Meril, VIRALDTECT II, TruPCR, Q-line, Allplex and TaqPath) which are commercially available for COVID-19 RT-PCR diagnosis. Materials and Methods: This observational study was conductedat the State Virology Laboratory (SVL), Gandhi Medical College, Bhopal, Madhya Pradesh, India. Seven commercially available kits have been evaluated on the basis of: (i) number of SARS-CoV-2 specific gene target; (ii) human housekeeping genes as internal control; (iii) RT-PCR run time; and (iv) kit performances to correctly detect SARS-CoV-2 positive and negative RNA samples. A total of 50 RNA samples (left over RNA) were included, master mix preparation, template addition and RT-PCR test has been performed according to kits literature. At the end of PCR run, mean and standard deviation of obtained cut-off of all kits were calculated using Microsoft Excel. Results: All seven RT-PCR kits performed satisfactory regarding the reproducibility and they could correctly identify 30 positive and 20 negative RNA samples. RNA samples (group C) having low viral loads with a high Cycle threshold (Ct) value (>30) were also detected by all these seven kits. Obtained Ct values of each group was in parallel range in comparison with the initial testing Ct values. Kits were found to be superior which contains primers and probes for three SARS-CoV-2 specific gene targets, have human housekeeping gene as internal control and taking less time to complete RT-PCR. Conclusion: All seven COVID-19 RT-PCR kits included in this study demonstrated satisfactory performance and can be used for the routine molecular diagnosis of COVID-19 disease.

Analysis of Antibiotic Resistance Genes and its Associated SCCmec Types among Nasal Carriage of Methicillin Resistant Coagulase Negative Staphylococci from Community Settings, Chennai, Southern India

OBJECTIVE

The study was designed to find the distribution of SCCmec types and the various antibiotic resistance genes amongst MR-CoNS isolates from asymptomatic individuals.

MATERIALS AND METHODS

A total of 145 nasal swabs were collected from asymptomatic healthy individuals from community settings. Identification and speciation of CoNS were done by standard biochemical methods. Screening of methicillin resistance (mecA gene) and detection of various antibiotic resistant genes were done using multiplex PCR method. SCCmec types (I - V) were determined using multiplex PCR.

RESULTS

50 (44.6%) isolates were found to be methicillin resistant both by cefoxitin method and multiplex PCR. S. epidermidis (40%) was the predominant species followed by S. haemolyticus (28%), S. hominis (20%) and S. warneri (12%). Highest resistance was shown for cotrimoxazole (26%), followed by ciprofloxacin (24%), tetracycline (20%), erythromycin (18%), fusidic acid (10%) and mupirocin (6%). Among SCCmec types, 44 isolates showed single type, including type I (30%), type IV (24%), type II (18%), type V (14%) and type III (2%). 6 isolates showed two types, III+IV (n= 2), II+V (n=2), IV+V (n=1) and type I+V (n=1).

CONCLUSION

In conclusion, to the best of our knowledge, this is the first study in India to study the distribution of antibiotic resistant genes and SCCmec types among MR-CoNS from community settings. This study highlights high prevalence of MR-CoNS in community and its role in harbouring genetically diverse SCCmec elements as antibiotic resistance determinant.

A controller based on Optimal Type-2 Fuzzy Logic: systematic design, optimization and real-time implementation

A computationally-efficient systematic procedure to design an Optimal Type-2 Fuzzy Logic Controller (OT2FLC) is proposed. The main scheme is to optimize the gains of the controller using Particle Swarm Optimization (PSO), then optimize only two parameters per type-2 membership function using Genetic Algorithm (GA). The proposed OT2FLC was implemented in real-time to control the position of a DC servomotor, which is part of a robotic arm. The performance judgments were carried out based on the Integral Absolute Error (IAE), as well as the computational cost. Various type-2 defuzzification methods were investigated in real-time. A comparative analysis with an Optimal Type-1 Fuzzy Logic Controller (OT1FLC) and a PI controller, demonstrated OT2FLC׳s superiority; which is evident in handling uncertainty and imprecision induced in the system by means of noise and disturbances.

Assessment of Clarias batrachus as a source of acetylcholinesterase (AchE) for the detection of insecticides

An inhibitive assay of insecticides using Acetylcholinesterase (AChE) from the local fish Clarias batrachus is reported. AChE was assayed according to the modified method of Ellman. Screening of insecticide and heavy metals showed that carbofuran and carbaryl strongly inhibited C. batrachus AChE. The inhibition concentration (IC) IC50 values (and the 95% confidence interval) for both carbofuran and carbaryl inhibition on C. batrachus AChE at 6.66 (5.97-7.52) and 130.00 (119.3-142.5) microg l(-1), respectively was within the IC50 range of Electrophorus electricus at 6.20 (6.03-6.39) and 133.01 (122.40-145.50) microg l(-1), respectively and were much lower than bovine AChE at 20.94 (19.53-22.58) and 418.80 (390.60-451.60) microg l(-1), respectively. The results showed that C. batrachus have the potential to be used as a cheaper and more readily available source of AChE than other more commercially available sources.

Isolation and characterization of a Pseudomonas diesel-degrading strain from Antarctica

A diesel-degrading bacterium from Antarctica has been isolated. The isolate was tentatively identified as Pseudomonas sp. strain DRYJ3 based on partial 16S rDNA molecular phylogeny and Biolog GN microplate panels and Microlog database. Growth on diesel was supported optimally by ammonium sulphate, nitrate and nitrite. The bacterium grew optimally in between 10 and 15 degrees C, pH 7.0 and 3.5% (v/v) diesel. The biodegradation of diesel oil by the strain increased in efficiency from the second to the sixth day of incubation from 1.4 to 18.8% before levelling off on the eighth day n-alkane oxidizing and aldehyde reductase activities were detected in the crude enzyme preparation suggesting the existence of terminal n-alkane oxidizing activity in this bacterium.