Development of an effective vaccination protocol to produce Salmonella-free layer fock

2021 ◽  
Vol 1 (2) ◽  
pp. 1-6
Author(s):  
Taslima Akter ◽  
Mohammed Nooruzzaman ◽  
Tanjin T. Mumu ◽  
Mustak Ahammed ◽  
ABM Jalal Uddin ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Serum Antibody ◽  
Antibody Responses ◽  
Salmonella Spp ◽  
Salmonella Gallinarum ◽  
Booster Immunization ◽  
Vaccination Protocol ◽  
Salmonella Infections ◽  
Positive Rate ◽  
Over Time

Salmonella infections are of prime importance in the layer chicken industry and pose a significant public health threat. Production of export quality poultry products requires Salmonella-free certification. We developed and applied a vaccination schedule based on a commercial live attenuated Salmonella enterica serovar Gallinarum biovar Gallinarum (S. Gallinarum) vaccine in a layer flock. A flock of 1000 ISA Brown chickens has vaccinated with a lyophilized fowl typhoid live vaccine at definite time intervals. Isolation of Salmonella spp. in cloacal swabs and detection of serum antibody responses were performed using serum plate agglutination (SPA) test and ELISA. At the time of vaccination (16 weeks (w) of age), 50% of the tested birds carried Salmonella spp. in feces. Following booster immunization at 18 w, 21 w, and then every 12 weeks interval, the shedding of Salmonella decreased significantly over time with 40% at 21 w, 10% at 30 w, and 5% each at 42 and 54 w, and no shedding was detected at 66 and 78 w. Biochemical analysis of 32 Salmonella isolates revealed 15.6% (n=5) Salmonella enterica serovar Gallinarum biovar Pullorum (S. Pullorum), 37.5% (n=12) Salmonella Gallinarum, and 46.9% (n=15) paratyphoid causing Salmonella. Of note, the Salmonella spp. detected after 21 w of age belonged to the paratyphoid group. The decreased shedding of bacteria paralleled with increased antibody responses. The antibody level at vaccination (20% positive rate at 16 w) increased over time with a 50% positive rate at 18 w, 80% at 42 w, 90% at 54 w, and 100% at 66 w and 78 w by serum plate agglutination (SPA) test. Similarly, the serum antibody levels of chickens were also measured using ELISA and were similar to the SPA test. In conclusion, the vaccine schedule developed in this study confirmed a high seroconversion and prevented Salmonella shedding in feces. Therefore, a three-month interval vaccination protocol from the pre-laying stage to the last stage of laying is recommended to prevent Salmonella infections in laying flocks.

scholarly journals Virulence Variation of Salmonella Gallinarum Isolates through SpvB by CRISPR Sequence Subtyping, 2014 to 2018

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2346
Author(s):  
Koeun Kim ◽  
Sunghyun Yoon ◽  
Yeong Bin Kim ◽  
Young Ju Lee
Keyword(s):  
Virulence Gene ◽  
High Morbidity ◽  
Gram Negative Bacteria ◽  
Salmonella Spp ◽  
Gram Negative ◽  
Salmonella Gallinarum ◽  
Changes Over Time ◽  
Sequence Types ◽  
Over Time ◽  
Virulence Variation

Salmonella Gallinarum is a Gram-negative bacteria that causes fowl typhoid, a septicemic disease with high morbidity and mortality that affects all ages of chickens. Although vaccines and antimicrobials have been used nationwide to eradicate the disease, the malady is still prevalent in Korea. In this study, we investigated the virulence and genetic variation of 116 S. Gallinarum isolates from laying hens between 2014 and 2018. A total of 116 isolates were divided into five Gallinarum Sequence Types (GST) through clustered regularly interspaced short palindromic repeats (CRISPR) subtyping method. The GSTs displayed changes over time. The 116 isolates showed no difference in virulence gene distribution, but the polyproline linker (PPL) length of the SpvB, one of the virulence factors of Salmonella spp., served as an indicator of S. Gallinarum pathogenicity. The most prevalent PPL length was 22 prolines (37.9%). The shortest PPL length (19 prolines) was found only in isolates from 2014 and 2015. However, the longest PPL length of 24 prolines appeared in 2018. This study indicates that PPLs of S. Gallinarum in Korea tend to lengthen over time, so the pathogenic potency of the bacteria is increasing. Moreover, the transition of GST was associated with PPL length extension over time. These results indicate that surveillance of changing GST and PPL length are necessary in the monitoring of S. Gallinarum isolates.

scholarly journals Evolution of immunity to SARS-CoV-2

2020 ◽  
Author(s):  
Adam K Wheatley ◽  
Jennifer A Juno ◽  
Jing J Wang ◽  
Kevin J Selva ◽  
Arnold Reynaldi ◽  
...  
Keyword(s):  
T Cell ◽  
Animal Studies ◽  
Vaccine Development ◽  
Natural Infection ◽  
Serum Antibody ◽  
Population Level ◽  
Antibody Responses ◽  
Cell Dynamics ◽  
Specific Memory ◽  
Over Time

The durability of infection-induced SARS-CoV-2 immunity has major implications for public health mitigation and vaccine development. Animal studies and the scarcity of confirmed re-infection suggests immune protection is likely, although the durability of this protection is debated. Lasting immunity following acute viral infection requires maintenance of both serum antibody and antigen-specific memory B and T lymphocytes and is notoriously pathogen specific, ranging from life-long for smallpox or measles4, to highly transient for common cold coronaviruses (CCC). Neutralising antibody responses are a likely correlate of protective immunity and exclusively recognise the viral spike (S) protein, predominantly targeting the receptor binding domain (RBD) within the S1 sub-domain. Multiple reports describe waning of S-specific antibodies in the first 2-3 months following infection. However, extrapolation of early linear trends in decay might be overly pessimistic, with several groups reporting that serum neutralisation is stable over time in a proportion of convalescent subjects. While SARS-CoV-2 specific B and T cell responses are readily induced by infection, the longitudinal dynamics of these key memory populations remains poorly resolved. Here we comprehensively profiled antibody, B and T cell dynamics over time in a cohort recovered from mild-moderate COVID-19. We find that binding and neutralising antibody responses, together with individual serum clonotypes, decay over the first 4 months post-infection, as expected, with a similar decline in S-specific CD4+ and circulating T follicular helper (cTFH) frequencies. In contrast, S-specific IgG+ memory B cells (MBC) consistently accumulate over time, eventually comprising a significant fraction of circulating MBC. Modelling of the concomitant immune kinetics predicts maintenance of serological neutralising activity above a titre of 1:40 in 50% of convalescent subjects to 74 days, with probable additive protection from B and T cells. Overall, our study suggests SARS-CoV-2 immunity after infection is likely to be transiently protective at a population level. SARS-CoV-2 vaccines may require greater immunogenicity and durability than natural infection to drive long-term protection.

scholarly journals Prevalence and Antimicrobial Resistances of Salmonella spp. Isolated from Wild Boars in Liguria Region, Italy

Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 568
Author(s):  
Elisabetta Razzuoli ◽  
Valeria Listorti ◽  
Isabella Martini ◽  
Laura Migone ◽  
Lucia Decastelli ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Wild Boar ◽  
Antimicrobial Susceptibility ◽  
Potential Risk ◽  
Salmonella Enterica ◽  
Intestinal Tract ◽  
Wild Boar Population ◽  
Salmonella Spp ◽  
Wild Boars ◽  
In The Wild

Salmonella spp. is an important zoonotic agent. Wild boars might host this pathogen in the intestinal tract and might represent a risk for Salmonella spp. transmission to humans. Wild boars are widely spread in Liguria, due to the environmental characteristics of the region. The aim of the study was the isolation, typing, and investigation of antimicrobial susceptibility of the isolated strains of Salmonella spp. During the 2013–2017 hunting seasons, 4335 livers of wild boars were collected and analyzed for the presence of Salmonella spp. A total of 260 strains of Salmonella spp. were isolated and characterized, with a prevalence of 6%. The isolated strains belonged to all six Salmonella enterica subspecies. Most of them were identified as Salmonella enterica subs. enterica of which 31 different serotypes were identified. The dominating serotype identified was S. Enteritidis. The antimicrobial resistance profiles of the isolated strains were analyzed against sixteen molecules. Of the isolated strains, 94.6% were resistant to at least one of the tested antimicrobials. This study showed the circulation of resistant Salmonella spp. strains in the wild boar population living in this area of Italy, underling the potential risk for these animals to disseminate this pathogen and its antimicrobial resistances.

scholarly journals Virulence and Antimicrobial Resistance Profiles of Salmonella enterica Serovars Isolated from Chicken at Wet Markets in Dhaka, Bangladesh

2021 ◽  
Vol 9 (5) ◽  
pp. 952
Author(s):  
Nure Alam Siddiky ◽  
Md Samun Sarker ◽  
Md. Shahidur Rahman Khan ◽  
Ruhena Begum ◽  
Md. Ehsanul Kabir ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Salmonella Enterica ◽  
Virulence Genes ◽  
Health Concern ◽  
Production Cycle ◽  
Salmonella Spp ◽  
Native Chicken ◽  
Resistance Patterns ◽  
Research Findings ◽  
Native Chickens

Virulent and multi drug resistant (MDR) Salmonellaenterica is a foremost cause of foodborne diseases and had serious public health concern globally. The present study was undertaken to identify the pathogenicity and antimicrobial resistance (AMR) profiles of Salmonellaenterica serovars recovered from chicken at wet markets in Dhaka, Bangladesh. A total of 870 cecal contents of broiler, sonali, and native chickens were collected from 29 wet markets. The overall prevalence of S. Typhimurium, S. Enteritidis, and untyped Salmonella spp., were found to be 3.67%, 0.57%, and 1.95% respectively. All isolates were screened by polymerase chain reaction (PCR) for eight virulence genes, namely invA, agfA, IpfA, hilA, sivH, sefA, sopE, and spvC. S. Enteritidis isolates carried all virulence genes whilst S. Typhimurium isolates carried six virulence genes except sefA and spvC. A diverse phenotypic and genotypic AMR pattern was found. Harmonic descending trends of resistance patterns were observed among the broiler, sonali, and native chickens. Interestingly, virulent and MDR Salmonella enterica serovars were found in native chicken, although antimicrobials were not used in their production cycle. The research findings anticipate that virulent and MDR Salmonella enterica are roaming in the wet markets which can easily anchor to the vendor, consumers, and in the food chain.

scholarly journals Salmonella enterica Subsp. houtenae Associated with an Abscess in Young Roe Deer (Capreolus capreolus)

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 654
Author(s):  
Adriana Trotta ◽  
Laura Del Sambro ◽  
Michela Galgano ◽  
Stefano Ciccarelli ◽  
Erika Ottone ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Roe Deer ◽  
Capreolus Capreolus ◽  
Epidemiological Data ◽  
Resistance Pattern ◽  
Salmonella Spp ◽  
Antibiotic Resistant ◽  
Biochemical Identification ◽  
Salmonella Pathogenicity Islands ◽  
Insight Into

Background: S. enterica subsp. houtenae has been rarely documented, and very limited genomic information is available. This report describes a rare case of primary extraintestinal salmonellosis in a young roe deer, associated with Salmonella enterica subsp. houtenae. Methods: A traditional cultural-based analysis was carried out from the contents of a neck abscess; biochemical identification and PCR assay were performed to isolate and identify the pathogen. Through whole-genome sequencing (WGS), multilocus sequence typing (MLST), core genome MLST (cgMLST), and the Salmonella pathogenicity islands (SPIs) survey, resistome and virulome genes were investigated to gain insight into the virulence and antimicrobial resistance of S. houtenae. Results: Biochemical identification and PCR confirmed the presence of Salmonella spp. in the swelling. The WGS analysis identified Salmonella enterica subspecies houtenae serovar 43:z4,z23:- and ST 958. The virulence study predicted a multidrug resistance pattern with resistance shown against aminoglycosides, tetracycline, beta-lactamase, fluoroquinolones, fosfomycin, nitroimidazole, aminocoumarin, and peptide. Fifty-three antibiotic-resistant genes were identified. No plasmids were detected. Conclusion: This study demonstrates the importance of continuous surveillance of pathogenic salmonellae. Biomolecular analyses combined with epidemiological data can provide important information about poorly described Salmonella strains and can help to improve animal welfare.

scholarly journals Kinetics of Anti-SARS-CoV-2 Antibody Responses 3 Months Post Complete Vaccination with BNT162b2; A Prospective Study in 283 Health Workers

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1942
Author(s):  
Evangelos Terpos ◽  
Ioannis P. Trougakos ◽  
Vangelis Karalis ◽  
Ioannis Ntanasis-Stathopoulos ◽  
Sentiljana Gumeni ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Health Workers ◽  
Antibody Responses ◽  
Healthy Individuals ◽  
Younger Age ◽  
Constant Rate ◽  
Rate Of Decline ◽  
A Prospective Study ◽  
Kinetics Of ◽  
Over Time

The aim of this study was to investigate the kinetics of neutralizing antibodies (NAbs) and anti-SARS-CoV-2 anti-S-RBD IgGs up to three months after the second vaccination dose with the BNT162b2 mRNA vaccine. NAbs and anti-S-RBD levels were measured on days 1 (before the first vaccine shot), 8, 22 (before the second shot), 36, 50, and three months after the second vaccination (D111) (NCT04743388). 283 health workers were included in this study. NAbs showed a rapid increase from D8 to D36 at a constant rate of about 3% per day and reached a median (SD) of 97.2% (4.7) at D36. From D36 to D50, a slight decrease in NAbs values was detected and it became more prominent between D50 and D111 when the rate of decline was determined at −0.11 per day. The median (SD) NAbs value at D111 was 92.7% (11.8). A similar pattern was also observed for anti-S-RBD antibodies. Anti-S-RBDs showed a steeper increase during D22–D36 and a lower decline rate during D36–D111. Prior COVID-19 infection and younger age were associated with superior antibody responses over time. In conclusion, we found a persistent but declining anti-SARS-CoV-2 humoral immunity at 3 months following full vaccination with BNT162b2 in healthy individuals.

scholarly journals Investigation of Salmonella Phage–Bacteria Infection Profiles: Network Structure Reveals a Gradient of Target-Range from Generalist to Specialist Phage Clones in Nested Subsets

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1261
Author(s):  
Khatuna Makalatia ◽  
Elene Kakabadze ◽  
Nata Bakuradze ◽  
Nino Grdzelishvili ◽  
Ben Stamp ◽  
...  
Keyword(s):  
Host Range ◽  
Salmonella Enterica ◽  
Target Range ◽  
Nested Subsets ◽  
Specific Phage ◽  
Salmonella Infections ◽  
Specialist Species ◽  
Host Infection ◽  
Salmonella Phage

Bacteriophages that lyse Salmonella enterica are potential tools to target and control Salmonella infections. Investigating the host range of Salmonella phages is a key to understand their impact on bacterial ecology, coevolution and inform their use in intervention strategies. Virus–host infection networks have been used to characterize the “predator–prey” interactions between phages and bacteria and provide insights into host range and specificity. Here, we characterize the target-range and infection profiles of 13 Salmonella phage clones against a diverse set of 141 Salmonella strains. The environmental source and taxonomy contributed to the observed infection profiles, and genetically proximal phages shared similar infection profiles. Using in vitro infection data, we analyzed the structure of the Salmonella phage–bacteria infection network. The network has a non-random nested organization and weak modularity suggesting a gradient of target-range from generalist to specialist species with nested subsets, which are also observed within and across the different phage infection profile groups. Our results have implications for our understanding of the coevolutionary mechanisms shaping the ecological interactions between Salmonella phages and their bacterial hosts and can inform strategies for targeting Salmonella enterica with specific phage preparations.

scholarly journals Multidrug Antimicrobial Resistance and Molecular Detection of mcr-1 Gene in Salmonella Species Isolated from Chicken

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 206
Author(s):  
Md Bashir Uddin ◽  
S.M. Bayejed Hossain ◽  
Mahmudul Hasan ◽  
Mohammad Nurul Alam ◽  
Mita Debnath ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Antimicrobial Resistance ◽  
In Silico ◽  
Salmonella Enterica ◽  
Molecular Mechanisms ◽  
Antimicrobial Agents ◽  
Genetic Relationships ◽  
Evolutionary Relationship ◽  
Salmonella Spp ◽  
Gram Negative

Colistin (polymyxin E) is widely used in animal and human medicine and is increasingly used as one of the last-resort antibiotics against Gram-negative bacilli. Due to the increased use of colistin in treating infections caused by multidrug-resistant Gram-negative bacteria, resistance to this antibiotic ought to be monitored. The study was undertaken to elucidate the molecular mechanisms, genetic relationships and phenotype correlations of colistin-resistant isolates. Here, we report the detection of the mcr-1 gene in chicken-associated Salmonella isolates in Bangladesh and its in-silico functional analysis. Out of 100 samples, 82 Salmonella spp. were isolated from chicken specimens (liver, intestine). Phenotypic disc diffusion and minimum inhibitory concentration (MIC) assay using different antimicrobial agents were performed. Salmonella isolates were characterized using PCR methods targeting genus-specific invA and mcr-1 genes with validation for the functional analysis. The majority of the tested Salmonella isolates were found resistant to colistin (92.68%), ciprofloxacin (73.17%), tigecycline (62.20%) and trimethoprim/sulfamethoxazole (60.98%). When screened using PCR, five out of ten Salmonella isolates were found to carry the mcr-1 gene. One isolate was confirmed for Salmonella enterica subsp. enterica serovar Enteritidis, and other four isolates were confirmed for Salmonella enterica subsp. enterica serovar Typhimurium. Sequencing and phylogenetic analysis revealed a divergent evolutionary relationship between the catalytic domain of Neisseria meningitidis lipooligosaccharide phosphoethanolamine transferase A (LptA) and MCR proteins, rendering them resistant to colistin. Three-dimensional homology structural analysis of MCR-1 proteins and molecular docking interactions suggested that MCR-1 and LptA share a similar substrate binding cavity, which could be validated for the functional analysis. The comprehensive molecular and in-silico analyses of the colistin resistance mcr-1 gene of Salmonella spp. of chicken origin in the present study highlight the importance of continued monitoring and surveillance for antimicrobial resistance among pathogens in food chain animals.

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