Three Rounds of Read Correction Significantly Improve Eukaryotic Protein Detection in ONT Reads.

BACKGROUND: Eukaryotes' whole-genome sequencing is crucial for species identification, gene detection, and protein annotation. Oxford Nanopore Technology (ONT) is an affordable and rapid platform for sequencing eukaryotes; however, the relatively higher error rates require computational and bioinformatic efforts to produce more accurate genome assemblies. Here, we evaluated the effect of read correction tools on eukaryote genome completeness, gene detection and protein annotation. METHODS: Reads generated by ONT of four eukaryotes, C. albicans, C. gattii, S. cerevisiae, and P. falciparum, were assembled using minimap2 and underwent three rounds of read correction using flye, medaka and racon. The generates consensus FASTA files were compared for total length (bp), genome completeness, gene detection, and protein-annotation by QUAST, BUSCO, BRAKER1 and InterProScan, respectively. RESULTS: Genome completeness was dependent on the assembly method rather than on the read correction tool; however, medaka performed better than flye and racon. Racon significantly performed better than flye and medaka in gene detection, while both racon and medaka significantly performed better than flye in protein-annotation. CONCLUSION: We show that three rounds of read correction significantly affect gene detection and protein annotation, which are dependent on assembly quality in preference to assembly completeness.

Whole Genome Sequencing: Applications in Clinical Bacteriology.

The success in determining the whole genome sequence of a bacterial pathogen was first achieved in 1995 by determining the complete nucleotide sequence of Haemophilus influenzae Rd using the chain-termination method established by Sanger et al. in 1977 and automated by Hood et al. in 1987. However, this technology was laborious, costly, and time-consuming. Since 2004, high-throughput next-generation sequencing technologies have been developed, which are highly efficient, require less time, and are cost-effective for whole genome sequencing (WGS) of all organisms, including bacterial pathogens. In recent years, the data obtained using WGS technologies coupled with bioinformatics analyses of the sequenced genomes have been projected to revolutionize clinical bacteriology. WGS technologies have been used in the identification of bacterial species, strains, and genotypes from cultured organisms and directly from clinical specimens. WGS has also helped in determining resistance to antibiotics by the detection of antimicrobial resistance genes and point mutations. Furthermore, WGS data have helped in the epidemiological tracking and surveillance of pathogenic bacteria in healthcare settings as well as in communities. This review focuses on the applications of WGS in clinical bacteriology.

Spatial Variations in the Nasal Microbiota of Staff Working in a Healthcare-Associated Research Core Facility.

OBJECTIVE: Workers in the healthcare sector are exposed to a multitude of bacterial genera. The location of their work contributes significantly to shaping personal microbiomes. In this study, we investigated the role of the workspace on the nasal bacteriome of staff working in a healthcare-associated research facility. METHODS: The anterior nares of 10 staff working in different laboratories on the ground and first floor of the research facility were aseptically swabbed. Genomic DNA from each sample was used to amplify the V3 and V4 regions of the 16S rRNA gene. The amplified products were sequenced using the MiSeq sequencer (Illumina). Operational taxonomic units were filtered through MG-RAST v.3.6. Taxonomic profiling and visualizations were performed in MicrobiomeAnalyst v2.0. RESULTS: The Wilcoxson Sum test at median abundances (p < 0.05) indicated that seven taxa (Micromonosporaceae, Micromonospora, Lactobacillaceae, Lactobacillus, Betaproteobacteria, Burkholderiales, Pectobacterium) were significantly diverse between ground-floor and first-floor workers. The analysis of similarity coefficient was 0.412 (p < 0.03) between the ground and the first-floor workers. Random forest analysis predicted 15 features that were significantly different (p < 0.05) in individuals working in different laboratories. Species richness and evenness also differed according to the placement of individuals in respective laboratories. CONCLUSION: These findings add to the knowledge that the healthcare support staff are at a speculated occupational risk. A slight shift in the abundances of bacterial genera and species might lead to unwanted consequences. Continual monitoring is thus warranted.

Recent Advances in Cancer Immunotherapy with a Focus on FDA-Approved Vaccines and Neoantigen-Based Vaccines.

Cancer immunotherapies refer to the concept of retraining the immune system to target malignant cells. Multiple immunotherapeutic options exist including immune modulating antibodies, immune stimulating cytokines, chimeric antigen receptor T cell therapy, and vaccines. Overall, this field has advanced rapidly as knowledge of the tumor microenvironment, immunological pathways, and biotechnology expands. Specifically, advancements in neoantigen identification, characterization, and formulation into a vaccine show promise. This review is focused on previously United States Food and Drug Administration-approved cancer therapeutic vaccines and neoantigen-based vaccine developments along with the associated relevant clinical trials.

Correction: Composition of nasal bacterial community and its seasonal variation in health care workers stationed in a clinical research laboratory.

[This corrects the article DOI: 10.1371/journal.pone.0260314.].

Chemical and Biological Characterization of Mycobacterium Tuberculosis-Specific ESAT6-Like Proteins and their Potentials in the Prevention of Tuberculosis and Asthma.

Early Secreted Antigenic Target 6 kDa (ESAT6) is a potent immunogenic protein secreted by the bacteria causing tuberculosis, i.e., Mycobacterium tuberculosis. Another highly immunogenic culture filtrate protein whose gene is linked to ESAT6/ESXA is known as CFP10/ESXB. Because of their high immunogenicity and specificity to M. tuberculosis, these proteins have been proposed as a vaccine to prevent tuberculosis and diagnose the active/latent disease. However, the same proteins cannot be used for prevention and diagnosis because immunized but healthy people will also show a positive response and be falsely reported as diseased. Therefore, in this review article, the search was made to identify if any other ESAT6-like proteins exist in the M. tuberculosis genome. The search identified 21 additional ESAT-like proteins, i.e., ESXC to ESXW. Immunological characterization has shown that some of them (especially ESXV) were able to induce immune responses in vitro with cells obtained from tuberculosis patients and healthy donors. When the protein ESXV was tested in different recombinant forms (expressed in Escherichia coli, mycobacterial vectors, and DNA plasmids) and injected in mice, immune responses were induced to multiple epitopes of the protein. Furthermore, immunization of mice with ESXV protected them from infection with M. tuberculosis. The same protein was also able to protect mice against the induction of asthma. These results suggest that ESXV has the potential to protect against two major diseases of the world, i.e., tuberculosis and asthma, and hence may be used as a common vaccine for both diseases.

The impact of applying various de novo assembly and correction tools on the identification of genome characterization, drug resistance, and virulence factors of clinical isolates using ONT sequencing.

Oxford Nanopore sequencing technology (ONT) is currently widely used due to its affordability, simplicity, and reliability. Despite the advantage ONT has over next-generation sequencing in detecting resistance genes in mobile genetic elements, its relatively high error rate (10-15%) is still a deterrent. Several bioinformatic tools are freely available for raw data processing and obtaining complete and more accurate genome assemblies. In this study, we evaluated the impact of using mix-and-matched read assembly (Flye, Canu, Wtdbg2, and NECAT) and read correction (Medaka, NextPolish, and Racon) tools in generating complete and accurate genome assemblies, and downstream genomic analysis of nine clinical Escherichia coli isolates. Flye and Canu assemblers were the most robust in genome assembly, and Medaka and Racon correction tools significantly improved assembly parameters. Flye functioned well in pan-genome analysis, while Medaka increased the number of core genes detected. Flye, Canu, and NECAT assembler functioned well in detecting antimicrobial resistance genes (AMR), while Wtdbg2 required correction tools for better detection. Flye was the best assembler for detecting and locating both virulence and AMR genes (i.e., chromosomal vs. plasmid). This study provides insight into the performance of several read assembly and read correction tools for analyzing ONT sequencing reads for clinical isolates.

The Prevalence of Multidrug-Resistant Enterobacteriaceae among Neonates in Kuwait.

Increasing numbers of neonates with serious bacterial infections, due to resistant bacteria, are associated with considerable morbidity and mortality rates. The aim of this study was to evaluate the prevalence of drug-resistant Enterobacteriaceae in the neonatal population and their mothers in Farwaniya Hospital in Kuwait and to determine the basis of resistance. Rectal screening swabs were taken from 242 mothers and 242 neonates in labor rooms and wards. Identification and sensitivity testing were performed using the VITEK® 2 system. Each isolate flagged with any resistance was subjected to the E-test susceptibility method. The detection of resistance genes was performed by PCR, and the Sanger sequencing method was used to identify mutations. Among 168 samples tested by the E-test method, no MDR Enterobacteriaceae were detected among the neonates, while 12 (13.6%) isolates from the mothers' samples were MDR. ESBL, aminoglycosides, fluoroquinolones, and folate pathway inhibitor resistance genes were detected, while beta-lactam-beta-lactamase inhibitor combinations, carbapenems, and tigecycline resistance genes were not. Our results showed that the prevalence of antibiotic resistance in Enterobacteriaceae obtained from neonates in Kuwait is low, and this is encouraging. Furthermore, it is possible to conclude that neonates are acquiring resistance mostly from the environment and after birth but not from their mothers.

Molecular epidemiology and genetic characterization of SARS-CoV-2 in Kuwait: A descriptive study.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been fatal to human health, affecting almost the entire world. Here we reported, for the first time, characterization of the genetic variants of SARS-CoV-2 circulating in Kuwait to understand their genetic diversity and monitor the accumulation of mutations over time. This study randomly enrolled 209 COVID-19 patients whose nasopharyngeal swabs were positive for SARS-CoV-2 between February 2020 and June 2021 using RT-PCR. The whole genomes of SARS-CoV-2 from the nasopharyngeal swabs were sequenced using the Oxford Nanopore sequencing technology following the ARTIC network protocol. Whole-genome sequencing has identified different clades/sub-clades circulating in Kuwait, mimicking the virus's global spread. Clade 20A was dominant from February 2020 until January 2021, and then clade 20I (Alpha, V1) emerged and dominated. In June 2021, the number of cases infected with clades 21I, 21A, and 21 J (Delta) increased and dominated. We detected several known clade-defining missense and synonymous mutations and other missense mutations in the genes encoding important viral proteins, including ORF1a, S, ORF3a, ORF8 regions and a novel mutation in the N region. ORF1ab region harbored more mutations and deletions (n = 62, 49.2%) compared to the other 12 gene regions, and the most prevalent missense mutations were P314L (97%) in ORF1b and D614G (97%) in the S glycoprotein regions. Detecting and analyzing mutations and monitoring the evolution of SARS-CoV-2 over time is essential to help better understand the spread of various clades/strains of SARS-CoV-2 and their implications for pathogenesis. In addition, knowledge of the circulating variants and genome sequence variability of SARS-CoV-2 may potentially influence the development of vaccines and antiviral drugs to control the COVID-19 pandemic.

Recent Updates on mRNA Vaccines.

Messenger RNA has been studied by everyone, from vaccine developers to high school biology students, since the discovery of its isolation in 1961 [...].

Immune Cells Profiles In The Peripheral Blood Of Patients With Moderate To Severe COVID-19 And Healthy Subjects With and Without Vaccination With The Pfizer-BioNTech mRNA Vaccine.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the causative agent of Coronavirus disease 2019 (COVID-19), has caused a global crisis. Patients with COVID-19 present with a range of clinical manifestations, from no symptoms to severe illness. However, little is known about the profiles of immune cells required to protect against SARS-CoV-2. This study was performed to determine the immune cells profiles in the peripheral blood of COVID-19 patients with moderate to severe disease (n=52), and compare the findings with those from healthy subjects vaccinated with Pfizer BioNTech mRNA vaccine (VS) (n=62), and non-vaccinated healthy subjects (HS) (n=30) from Kuwait. Absolute counts and percentages of total lymphocytes and lymphocyte subsets (CD3+ T cells, CD4+ T cells, CD8+ T cells, CD19+ B cells, and CD16+CD56+ NK cells) in the peripheral blood of the three groups were analyzed using flow cytometry. The results showed that the absolute counts of total lymphocytes, CD3+, CD4+, and CD8+ T cells, CD19+ B cells, and CD56+ NK cells, were significantly lower in COVID-19 patients than normal healthy controls and vaccinated subjects. The percentages of CD3+ and CD4+ T lymphocytes were also significantly lower in the COVID-19 patients. However, the percentage of CD16+CD56+ NK cells was significantly higher in the peripheral blood of COVID-19 patients, compared to the HS and VS groups with no detectable differences in the percentages of CD8+ T cells and CD19+ B cells between the three groups. Analysis of the monocyte subsets has showed a significantly higher percentage of CD14+HLA-DR+ monocytes in COVID-19 patients compared to HS whereas the inflammatory CD14+CD16+ HLA-DR+ monocytes, and the non-classical CD16+HLA-DR+ monocytes showed significantly lower frequency in the blood of the patients than that of HS. These findings demonstrate perturbations of both innate and adaptive immune cell subsets that reflect dysregulated host responses in COVID-19 patients with moderate to severe disease.

The Effect of Delivery Systems on the Induction of T Helper 1 Cell Response to an ESAT6-Like Protein Rv3619c and Identification of Its Immunodominant Peptides.

OBJECTIVE: This study determined the effects of chemical adjuvants, incomplete Freund's adjuvant (IFA) and aluminum hydroxide (Alum), mycobacteria, and a DNA plasmid as delivery systems on the induction of protective Th1 (interferon-gamma (IFN-γ)) and nonprotective Th2 (IL-5) and Treg (IL-10) cytokine responses to Rv3619c and its peptides. Rv3619c is an immunodominant Mycobacterium tuberculosis-specific antigen and belongs to the early-secreted antigenic target of 6 kDa-family of proteins. Delivery systems are needed to deliver such antigens in animal models and induce protective immune responses. METHODS: The rv3619c gene was amplified from the genomic DNA of M. tuberculosis and cloned into appropriate vectors for expression in Escherichia coli, Mycobacterium smegmatis, and eukaryotic cells. Spleen cells from mice immunized with rv3619c using different delivery systems were stimulated in vitro with synthetic peptides (P1 to P6) of Rv3619c, and secreted cytokines were estimated by ELISA. RESULTS: The recombinant M. smegmatis and DNA plasmid induced the secretion of the protective cytokine IFN-γ in response to peptide-pool of Rv3619c and all the individual peptides, whereas rv3619c/IFA induced the secretion of IFN-γ in response to the peptide pool, and the peptides P5 and P6. However, the secretions of the nonprotective cytokines IL-5 and IL-10 were induced to none of the peptides with the delivery systems used. CONCLUSION: Rv3619c is a major antigen of M. tuberculosis with multiple immunogenic epitopes; however, immune responses to individual epitopes can vary based on delivery systems used.

Evaluation of in vitro activity of ceftolozane/tazobactam and comparators against recent clinical bacterial isolates, and genomics of Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli isolates that demonstrated resistance to ceftolozane/tazobactam: data from Kuwait and Oman.

Background: The treatment options for infections caused by MDR Gram-negative bacteria have been limited, especially for infections caused by bacteria that produce carbapenemases and/or ESBLs. Ceftolozane/tazobactam is a cephalosporin/ß-lactamase inhibitor developed to treat Gram-negative bacteria. Methods: Ceftolozane/tazobactam and 14 comparators (amikacin, aztreonam, cefepime, cefotaxime, cefoxitin, ceftazidime, ceftriaxone, ciprofloxacin, colistin, ertapenem, imipenem, levofloxacin, meropenem and piperacillin/tazobactam) were evaluated against Pseudomonas aeruginosa and Enterobacterales isolates collected from Kuwait and Oman (n = 606) during 2016-17. In addition, further analysis of resistance mechanisms to ceftolozane/tazobactam was done utilizing WGS. Non-susceptible isolates from ceftolozane/tazobactam surveillance were selected for analysis. Overall, 35 strains underwent WGS. Results: Among isolates from Kuwait, susceptibility of P. aeruginosa, Escherichia coli and Klebsiella pneumoniae to ceftolozane/tazobactam was 79.8%, 95.7% and 87.5%, respectively, and from Oman was 92.3%, 93.1% and 88.5%, respectively. No P. aeruginosa with a ceftolozane/tazobactam MIC <32 mg/L encoded ß-lactamases besides normal chromosomal enzymes (PDC variants or OXA-50-like) whereas all but one P. aeruginosa isolate with MIC >32 mg/L encoded either MBLs (60%), VEB-1 (19%) or additional OXAs (3.7%). Conclusions: Colistin followed by ceftolozane/tazobactam showed the greatest activity against P. aeruginosa. Enterobacterales showed more susceptibility to ceftolozane/tazobactam than to piperacillin/tazobactam, but meropenem and colistin showed better activity.

Distribution of vitamin D-binding protein/group-specific component gene subtypes in Kuwaiti population.

BACKGROUND: Vitamin D-binding protein or group-specific component (Gc) is the major plasma carrier protein of Vitamin D. Two single nucleotide polymorphisms, rs7041 (NM_000583.3:c.1296G>T;NP_000574.2:p.Asp432Glu) and rs4588 (c.1307C>A; p.Thr436Lys), in the GC gene result in three major genotypes, that is, GC1F (c.1296T, c.1307C), GC1S (c.1296G, c.1307C), GC2 (c.1296T, c.1307A), and phenotypes such as Gc1F (p.432Asp, p.436Thr), Gc1S (p.432Glu, p.436Thr), and Gc2 (p.432Asp, p.436Lys). Significant variations in the frequencies of GC subtypes (genotypes/phenotypes) are reported in different populations living in different geographical locations, for example, GC1S/Gc1S (c.1296G, c.1307C/p.432Glu, p.436Thr) and GC2/Gc2 (c.1296T, c.1307A/p.432Asp, p.436Lys) are predominant in Caucasians and people living in the northern hemisphere, and GC1F/Gc1F (c.1296T, c.1307C/p.432Asp, p.436Thr) is predominant in Africans. However, frequencies of major GC subtypes are not known in the Kuwaiti population. In this study, we investigated 512 alleles to identify the major GC subtypes in Kuwaiti nationals. METHODS: Genomic DNA was isolated from blood samples of 128 healthy subjects. DNA regions covering the targeted mutations were amplified by PCR. Amplified DNAs were sequenced by the Sanger method and analyzed for specific mutations to determine the GC genotypes and phenotypes. RESULTS: The results identified the presence of four GC genotypes/phenotypes namely GC1F/Gc1F (c.1296T, c.1307C/p.432Asp, p.436Thr), GC1S/Gc1S (c.1296G, c.1307C/p.432Glu, p.436Thr), GC2/Gc2 (c.1296T, c.1307A/p.432Asp, p.436Lys), and GC3/Gc3 (c.1296G;c.1307A/p.432Glu, p.436Lys). Among the allelic subtypes (n = 512), GC1S (c.1296G; c.1307C) (n = 270, 52.7%) was predominant, followed by GC1F (c.1296T; c.1307C) (n = 138, 27%), GC2 (c.1296T; c.1307A) (n = 72, 14%), and GC3 (c.1296G; c.1307A) (n = 32, 6.3%). Three common subtypes, that is, GC1F (c.1296T; c.1307C), GC1S (c.1296G; c.1307C), and GC2 (c.1296T; c.1307A) are well documented in the literature, but GC3 (c.1296T; c.1307A) is an uncommon variant found in our study subjects. CONCLUSION: We found that GC subtype distribution was unique in the Kuwaiti population, with some affinity to Caucasians. Several factors including ancestral origin, migration history, and environmental forces such as solar intensity may be responsible for the unique distribution of GC subtypes in this population.

Early secreted antigenic target of 6 kda-like proteins of mycobacterium tuberculosis: Diagnostic and vaccine relevance.

Background: Early secreted antigenic target of 6 kDa (ESAT6) is low-molecular-weight and immunodominant protein of Mycobacterium tuberculosis with relevance to diagnosis and vaccine development. Analysis of the M. tuberculosis genome has shown the existence of 23 ESAT6-like genes. This study was aimed to determine M. tuberculosis-specificity vis-à-vis crossreactivity of ESAT6-like genes and encoded proteins and their potential in the diagnosis and vaccine development. Methods: All ESAT6-like proteins were characterized using the webserver Tuberculist. The sequence identities were determined using basic local alignment search tool. Results: The genes for six ESAT6-like proteins were located in M. tuberculosis-specific genomic regions of differences (RDs), i.e., EsxA and EsxB in RD1, EsxO and EsxP in RD7, and EsxV and EsxW in RD9. The genes for other ESAT6-like proteins were located in the genomic regions shared with other mycobacteria. Based on sequence identities, the ESA6-like proteins were divided into four subfamilies of 15 proteins and no subfamily of 8 proteins. The members of subfamilies 1-4 shared extensive sequence identities among the members of each subfamily. Each member of subfamily 1 (EsxI, EsxL, EsxN, EsxO, EsxV) and subfamily 2 (EsxJ, EsxK, EsxM, EsxP, EsxW) were homologs. Hence, the gene sequences identical to EsxO and EsxP located in RD7, and EsxV and EsxW located in RD9 were also present in the regions of M. tuberculosis genome shared with other mycobacteria. Conclusion: Because of their specificity to M. tuberculosis, only EsxA (ESAT6) and EsxB (CFP10) will be useful in the specific diagnosis. However, other ESAT6-like proteins may be useful for vaccine development against tuberculosis.

Composition of nasal bacterial community and its seasonal variation in health care workers stationed in a clinical research laboratory.

The microorganisms at the workplace contribute towards a large portion of the biodiversity a person encounters in his or her life. Health care professionals are often at risk due to their frontline nature of work. Competition and cooperation between nasal bacterial communities of individuals working in a health care setting have been shown to mediate pathogenic microbes. Therefore, we investigated the nasal bacterial community of 47 healthy individuals working in a clinical research laboratory in Kuwait. The taxonomic profiling and core microbiome analysis identified three pre-dominant genera as Corynebacterium (15.0%), Staphylococcus (10.3%) and, Moraxella (10.0%). All the bacterial genera exhibited seasonal variations in summer, winter, autumn and spring. SparCC correlation network analysis revealed positive and negative correlations among the classified genera. A rich set of 16 genera (q < 0.05) were significantly differentially abundant (LEfSe) across the four seasons. The highest species counts, richness and evenness (P < 0.005) were recorded in autumn. Community structure profiling indicated that the entire bacterial population followed a seasonal distribution (R2-0.371; P < 0.001). Other demographic factors such as age, gender and, ethnicity contributed minimally towards community clustering in a closed indoor laboratory setting. Intra-personal diversity also witnessed rich species variety (maximum 6.8 folds). Seasonal changes in the indoor working place in conjunction with the outdoor atmosphere seems to be important for the variations in the nasal bacterial communities of professionals working in a health care setting.

Adjuvants and Antigen-Delivery Systems for Subunit Vaccines against Tuberculosis.

The only licensed vaccine against tuberculosis is BCG. However, BCG has failed to provide consistent protection against tuberculosis, especially pulmonary disease in adults. Furthermore, the use of BCG is contraindicated in immunocompromised subjects. The research towards the development of new vaccines against TB includes the use of Mycobacterium tuberculosis antigens as subunit vaccines. Such vaccines may be used either alone or in the prime-boost model in BCG-vaccinated people. However, the antigens for subunit vaccines require adjuvants and/or delivery systems to induce appropriate and protective immune responses against tuberculosis and other diseases. Articles published in this Special Issue have studied the pathogenesis of BCG in children and the use of BCG and recombinant BCG as potential vaccines against asthma. Furthermore, the use of different adjuvants and delivery systems in inducing the protective immune responses after immunization with subunit vaccines has been described.

Current Status of HIV-1 Vaccines.

HIV-1 infection and its progression to AIDS remains a significant global health challenge, particularly for low-income countries. Developing a vaccine to prevent HIV-1 infections has proven to be immensely challenging with complex biological acquisition and infection, unforeseen clinical trial disappointments, and funding issues. This paper discusses important landmarks of progress in HIV-1 vaccine development, various vaccine strategies, and clinical trials.

Immunological Characterization of Proteins Expressed by Genes Located in Mycobacterium tuberculosis-Specific Genomic Regions Encoding the ESAT6-like Proteins.

The 6 kDa early secreted antigen target (ESAT6) is a low molecular weight and highly immunogenic protein of Mycobacterium tuberculosis with relevance in the diagnosis of tuberculosis and subunit vaccine development. The gene encoding the ESAT6 protein is located in the M. tuberculosis-specific genomic region known as the region of difference (RD)1. There are 11 M. tuberculosis-specific RDs absent in all of the vaccine strains of BCG, and three of them (RD1, RD7, and RD9) encode immunodominant proteins. Each of these RDs has genes for a pair of ESAT6-like proteins. The immunological characterizations of all the possible proteins encoded by genes in RD1, RD7 and RD9 have shown that, besides ESAT-6 like proteins, several other proteins are major antigens useful for the development of subunit vaccines to substitute or supplement BCG. Furthermore, some of these proteins may replace the purified protein derivative of M. tuberculosis in the specific diagnosis of tuberculosis by using interferon-gamma release assays and/or tuberculin-type skin tests. At least three subunit vaccine candidates containing ESAT6-like proteins as antigen components of multimeric proteins have shown efficacy in phase 1 and phase II clinical trials in humans.

BCG as a Vector for Novel Recombinant Vaccines against Infectious Diseases and Cancers.

Bacillus Calmette-Guérin (BCG) has been widely used globally as a prophylactic vaccine to protect against tuberculosis (TB) for about a century [...].