Prevalent Serovars Research Articles

Virulence, antimicrobial susceptibility and phylogenetic analysis of Cronobacter sakazakii isolates of food origins from Jordan.

The aim was to characterize a collection of Cronobacter sakazakii isolates collected from various origins in Jordan. The isolates were characterized using 16S rRNA sequencing, DNA microarray, multi-locus sequence typing (MLST), O-serotyping, virulence gene identification and antibiotic susceptibility testing. The identities and phylogenetic relatedness revealed that C. sakazakii sequence type 4 (ST4) and Csak O:1 serotype were the most prevalent STs and serovars amongst these C. sakazakii strains. PCR screening of putative virulence genes showed that the siderophore-interacting protein gene (sip) and iron acquisition gene clusters (eitCBAD and iucABCD/iutA) were the most detected genes with noticeable variability in the type 6 secretion system (T6SS) and filamentous hemagglutinin/adhesion (FHA) gene loci. The antibiotic resistance profiles revealed that the majority of the isolates were susceptible to all antibiotics used despite harbouring a class C β-lactamase resistance gene. The results described in this report provide additional insights about the considerable genotypic and phenotypic heterogeneity within C. sakazakii. The information reported in this study might be of great value in understanding the origins of C. sakazakii isolates, in addition to their diversity and variability, which might be helpful in preventing future outbreaks of this pathogen.

Phylogenomic Analysis of Salmonella enterica Serovar Indiana ST17, an Emerging Multidrug-Resistant Clone in China.

ABSTRACTSalmonella enterica serovar Indiana (S. Indiana) is an extremely expanded foodborne pathogen in China in recent years. This study aimed to elucidate the national prevalence and phylogenomic characterization of this pathogen in China. Among 5, 287 serotyped Salmonella isolates collected during 2002 to 2018, 466 S. Indiana isolates were found in 15 provinces, and 407 were identified to be ST17, and the rest were ST2040. Among 407 ST17 isolates, 372 (91.4%) were multidrug resistant, and 366 (89.9%) were resistant to ciprofloxacin, 235 (57.7%) were further resistant to ceftriaxone. Phylogenomic analysis revealed that ST17 isolates were classified into four clades (I, II, III and IV), which appeared in international clonal dissemination. ST17 isolates from China fell into Clade IV with part of isolates from the United Kingdom, the United States, South Korea, and Thailand, suggesting their close genetic relationship. Mutations in quinolone resistance-determining regions (QRDR) of GyrA and ParC, and plasmid-mediated quinolone resistance (PMQR) genes aac(6′)-Ib-cr, oqxAB, and qnrS as well as extended spectrum β-lactamases (ESBL) genes blaCTX-M, blaOXA, and blaTEM in isolates from Clade IV were much higher than those from other three clades. Various blaCTX-M subtypes (blaCTX-M-65, blaCTX-M-55, blaCTX-M-27, blaCTX-M-14, and blaCTX-M-123) with ISEcp1, IS903B, ISVsa5, and IS1R were found in ST17 isolates, especially Tn1721 containing ΔISEcp1-blaCTX-M-27-IS903B in P1-like bacteriophage plasmids. These findings on the prevalent and genomic characterization for the S. Indiana multidrug-resistant ST17 clone in China, which have not been reported yet, provide valuable insights into the potential risk of this high-resistant clone.IMPORTANCE Fluoroquinolones and cephalosporins are the primary choices for severe salmonellosis treatment. S. Indiana has become one of the most prevalent serovars in breeding poultry and poultry meats in China in recent years. ST17 was recognized as the leading epidemiological importance in S. Indiana because of its high-level resistance to the most of common antibiotics, including ciprofloxacin and ceftriaxone. However, the prevalence and phylogenomic characterization of ST17 isolates are unclear. Here, we did a retrospective screening on a large scale for S. Indiana in China, and performed its phylogenomic analysis. It was found that ST17 isolates had extensive spread in 15 provinces of China and became a multidrug-resistant clone. The international spread of the ST17 isolates was observed among several countries, especially China, the United Kingdom, and the United States. Our study emphasized the importance of surveillance of a high-resistant S. Indiana ST17 clone to combat its threat to public health.

Dynamics of Salmonella enterica and antimicrobial resistance in the Brazilian poultry industry and global impacts on public health.

Non-typhoidal Salmonella enterica is a common cause of diarrhoeal disease; in humans, consumption of contaminated poultry meat is believed to be a major source. Brazil is the world’s largest exporter of chicken meat globally, and previous studies have indicated the introduction of Salmonella serovars through imported food products from Brazil. Here we provide an in-depth genomic characterisation and evolutionary analysis to investigate the most prevalent serovars and antimicrobial resistance (AMR) in Brazilian chickens and assess the impact to public health of products contaminated with S. enterica imported into the United Kingdom from Brazil. To do so, we examine 183 Salmonella genomes from chickens in Brazil and 357 genomes from humans, domestic poultry and imported Brazilian poultry products isolated in the United Kingdom. S. enterica serovars Heidelberg and Minnesota were the most prevalent serovars in Brazil and in meat products imported from Brazil into the UK. We extended our analysis to include 1,259 publicly available Salmonella Heidelberg and Salmonella Minnesota genomes for context. The Brazil genomes form clades distinct from global isolates, with temporal analysis suggesting emergence of these Salmonella Heidelberg and Salmonella Minnesota clades in the early 2000s, around the time of the 2003 introduction of the Enteritidis vaccine in Brazilian poultry. Analysis showed genomes within the Salmonella Heidelberg and Salmonella Minnesota clades shared resistance to sulphonamides, tetracyclines and beta-lactams conferred by sul2, tetA and blaCMY-2 genes, not widely observed in other co-circulating serovars despite similar selection pressures. The sul2 and tetA genes were concomitantly carried on IncC plasmids, whereas blaCMY-2 was either co-located with the sul2 and tetA genes on IncC plasmids or independently on IncI1 plasmids. Long-term surveillance data collected in the UK showed no increase in the incidence of Salmonella Heidelberg or Salmonella Minnesota in human cases of clinical disease in the UK following the increase of these two serovars in Brazilian poultry. In addition, almost all of the small number of UK-derived genomes which cluster with the Brazilian poultry-derived sequences could either be attributed to human cases with a recent history of foreign travel or were from imported Brazilian food products. These findings indicate that even should Salmonella from imported Brazilian poultry products reach UK consumers, they are very unlikely to be causing disease. No evidence of the Brazilian strains of Salmonella Heidelberg or Salmonella Minnesota were observed in UK domestic chickens. These findings suggest that introduction of the Salmonella Enteritidis vaccine, in addition to increasing antimicrobial use, could have resulted in replacement of salmonellae in Brazilian poultry flocks with serovars that are more drug resistant, but less associated with disease in humans in the UK. The plasmids conferring resistance to beta-lactams, sulphonamides and tetracyclines likely conferred a competitive advantage to the Salmonella Minnesota and Salmonella Heidelberg serovars in this setting of high antimicrobial use, but the apparent lack of transfer to other serovars present in the same setting suggests barriers to horizontal gene transfer that could be exploited in intervention strategies to reduce AMR. The insights obtained reinforce the importance of One Health genomic surveillance.

Prevalence, Antibiotic-Resistance, and Replicon-Typing of Salmonella Strains among Serovars Mainly Isolated from Food Chain in Marche Region, Italy.

Nontyphoidal salmonellosis (NTS) is the second most commonly reported gastrointestinal infection in humans and an important cause of food-borne outbreaks in Europe. The use of antimicrobial agents for animals, plants, and food production contributes to the development of antibiotic-resistant Salmonella strains that are transmissible to humans through food. The aim of this study was to investigate the presence and the potential dissemination of multidrug-resistant (MDR) Salmonella strains isolated in the Marche Region (Central Italy) via the food chain. Strains were isolated from different sources: food, human, food animal/livestock, and the food-processing environment. Among them, we selected MDR strains to perform their further characterization in terms of resistance to tetracycline agent, carriage of tet genes, and plasmid profiles. Tetracycline resistance genes were detected by PCR and plasmid replicons by PCR-based replicon typing (PBRT). A total of 102 MDR Salmonella strains were selected among the most prevalent serovars: S. Infantis (n = 36/102), S. Derby (n = 20/102), S. Typhimurium (n = 18/102), and a monophasic variant of S. Typhimurium (MVST, n = 28/102). Resistance to sulfisoxazole (86%) and tetracycline (81%) were the most common, followed by ampicillin (76%). FIIS was the most predominant replicon (17%), followed by FII (11%) and FIB (11%) belonging to the IncF incompatibility group. Concerning the characterization of tet genes, tetB was the most frequently detected (27/89), followed by tetA (10/89), tetG (5/89), and tetM (1/89). This study showed the potential risk associated with the MDR Salmonella strains circulating along the food chain. Hence, epidemiological surveillance supported by molecular typing could be a very useful tool to prevent transmission of resistant Salmonella from food to humans, in line with the One Health approach.

Comparison of microbiological, pathological, and zootechnical aspects between broiler chickens and turkeys challenged with Salmonella Heidelberg

Salmonella remains the second most common cause of gastrointestinal illness in the United States, European Union and other regions of the globe. In the food chain, poultry, especially turkeys and chickens, are considered significant contributors to salmonellosis in humans, as their intestinal tracts are often colonized with Salmonella . Due to changes in the prevalence of serovars, Salmonella Heidelberg ( SH ) has gained prominence, especially in the United States and Brazil, where outbreaks have occurred in recent years. The transmission of salmonella can occur by different routes, whether by infected breeding flocks, previously infected flocks, contaminated food or water. Thus, eliminating the bacteria from the installations can be a difficult task. In this sense, several countries have implemented salmonella control programs on poultry farms, in order to reduce its presence. Our study demonstrated that, despite the similarity between bird species and their rearing systems, turkeys are more sensitive to the Heidelberg serovar, especially in relation to microbiological contamination of internal organs and elimination of the agent into the environment. This information is extremely relevant for the poultry industry, enabling it to improve biosecurity programs in this species.

A recombinant Chlamydia muridarum MOMP encapsulated PLGA 85/15 nanovaccine induced antibodies elicited cross-recognition of serovar-D elementary bodies

Abstract Chlamydia trachomatis (Ct), caused by various serovars, remains the leading sexually transmitted bacterial infection worldwide. An efficient delivery system is critical to developing whole or subunit vaccines against Ct, and vaccine developmental efforts are rapidly targeting biodegradable nanoparticles based vaccines with encapsulated antigens. We have developed a nanovaccine employing the recombinant major outer membrane protein (rMOMP) of C. muridarum (Cm) encapsulated in poly (lactic acid-co-glycolic acid) (PLGA) 85/15 (PLGA-rMOMP). We previously compared the humoral responses of priming routes; subcutaneous (SC) or intramuscular (IM-p) followed by two sc-boosts to evaluate rMOMP specific serum antibodies [Th1 (IgG2a, IgG2b), Th2 (IgG1)] produced by PLGA-rMOMP immunization of female BALB/c mice. Here we explored the ability of systemic antibodies produced in immunized mice to recognize UV-inactivated whole elementary bodies (EB) of Cm and one of the prevalent human serovar D (Ct-D) using antigen-specific ELISA. Serum from phosphate-buffered saline (PBS) or PBS encapsulated (PLGA-PBS) groups of mice served as a negative control to validate the EB recognition by immunized sera. We observed higher EB specific total IgG (4-fold) and isotypes IgG2b (16-fold), IgG1 (2-fold) antibodies recognizing Ct-D compared to Cm for the SC and IM-p immunization groups. Evaluation of the Th1 (IgG2b)/Th2 (IgG1) antibody titer ratio revealed a higher Th1 antibody recognition of Cm (4-fold) and Ct-D (16-fold), for the SC and IM-p immunization routes. Our data show that mice immunized with PLGA-rMOMP produced Th1 systemic antibodies against EB, but more importantly, there was robust serological cross recognition of the human serovar D. This research was supported by the National Institute Of Allergy And Infectious Diseases of the National Institutes of Health under Award Number R21AI111159, NIH-NIGMS-RISE (1R25GM106995-01) and the National Science Foundation (NSF)-CREST (HRD-1241701) and NSF-HBCU-RISE (HRD-1646729) grants.

Prevalence and characterization of Salmonella from meat in slaughterhouses in Hangzhou, China

Salmonella is an essential food-borne pathogenic microorganism. Humans could get infected by consuming of Salmonella-contaminated foods, especially contaminated meat. In this study, a total of 580 retail meat samples (280 pork, 240 chicken, and 60 goose) were collected from slaughterhouses in Hangzhou to determine the prevalence and antimicrobial susceptibility patterns of Salmonella. Isolates were characterized by serotyping, PFGE (Pulsed-field gel electrophoresis), Polymerase chain reaction (PCR), and antibiotic susceptibility testing. The rates of Salmonella-positive pork, chicken, and goose samples were 21.1% (n = 59), 10.4% (n = 25) and 10.0% (n = 6), respectively. The prevalence of Salmonella was 15.5% in slaughterhouses. Thirteen different Salmonella serovars were identified, and 6 isolates could not be identified. The most commonly prevalent serovars are Salmonella Rissen (S. Rissen) (n = 20, 22.2%), S. Derby (n = 16, 17.8%) and S. Typhimurium (n = 12, 13.3%). The detection rate of the remaining serovars ranged from 1.1%–11.11%. All Derby, Corvallis, and Kentucky strains were from pork. Seventy-two isolates (80.0%) showed drug resistance (DR) to at least one antibiotics, 19 (21.1%) were multi-drug resistant strains, 2 (2.2%) showed seven or more. The detection rate of Trimethoprim/Sulfamethoxazole-resistance (70.0%) was highest, followed by Ampicillin (55.6%). Salmonella resistance was found related to serovar and origin. The positive rates of DR gene sul1, sul2, sul3, class I integrons and blaTEM were 92.2%, 95.6%, 86.7%, 83.3% and 62.2%, respectively. Fifty-seven different PFGE patterns and 7 main clusters were obtained. This study revealed the high positive rates of Salmonella resistance and related DR genes, especially for Sulfamethoxazole-resistance and its related gene.

Rapid Detection of Actinobacillus pleuropneumoniae From Clinical Samples Using Recombinase Polymerase Amplification.

Actinobacillus pleuropneumoniae (APP) is the causative agent of porcine pleuropneumonia, resulting in high economic impact worldwide. There are currently 19 known serovars of APP, with different ones being predominant in specific geographic regions. Outbreaks of pleuropneumonia, characterized by sudden respiratory difficulties and high mortality, can occur when infected pigs are brought into naïve herds, or by those carrying different serovars. Good biosecurity measures include regular diagnostic testing for surveillance purposes. Current gold standard diagnostic techniques lack sensitivity (bacterial culture), require expensive thermocycling machinery (PCR) and are time consuming (culture and PCR). Here we describe the development of an isothermal point-of-care diagnostic test - utilizing recombinase polymerase amplification (RPA) for the detection of APP, targeting the species-specific apxIVA gene. Our APP-RPA diagnostic test achieved a sensitivity of 10 copies/μL using a strain of APP serovar 8, which is the most prevalent serovar in the UK. Additionally, our APP-RPA assay achieved a clinical sensitivity and specificity of 84.3 and 100%, respectively, across 61 extracted clinical samples obtained from farms located in England and Portugal. Using a small subset (n = 14) of the lung tissue samples, we achieved a clinical sensitivity and specificity of 76.9 and 100%, respectively) using lung imprints made on FTA cards tested directly in the APP-RPA reaction. Our results demonstrate that our APP-RPA assay enables a suitable rapid and sensitive screening tool for this important veterinary pathogen.

Analysis of Prevalent Leptospira Serovars in Different Animals of South Gujarat Region during Year of 2020

Analysis of Prevalent Leptospira Serovars in Different Animals of South Gujarat Region during Year of 2020

Leptospirosis in Dairy Cattle from Southern Brazil - Risk Factors

Background: Cattle are susceptible to chronic leptospirosis infection, that results in reduced milk production and reproductive disorders such as abortions, stillbirths, fetal malformation, and mummified fetuses, causing significant economic losses. Commercially available vaccines against leptospirosis offer limited protection to cattle because they contain only the most prevalent serovars worldwide, even though they are not prevalent in the specific region. This study aimed to evaluate the prevalence of specific antibodies against Leptospira serogroups, reproductive disorders and the risk factors in dairy herds from different mesoregions of Rio Grande do Sul State, Southern Brazil.Materials, Methods & Results: An epidemiological survey was conducted, and serum samples from the bovine population representative of three mesoregions (MR1, MR2, and MR3) were studied; the samples were collected and tested for leptospirosis using the microscopic agglutination test (MAT) for 12 serogroups checking for the presence of agglutination. A total of 442 blood samples were collected from dairy cattle from November to December 2019 (MR1, 187; MR2, 88; and MR3, 167), including cows vaccinated with different commercial vaccines during the three months before sample collection (n = 295) and non-vaccinated against leptospirosis (n = 147). At the time of collection, an interview was conducted with the owners with questions about the health of the animals, management, habitat, feeding and reproduction. Chi-square tests univariate analysis with the SPSS® version 20.0 were performed to estimate the association of serogroup Djasiman seroreactivity with the occurrence of reproductive problems and related risk factors. The mean prevalence of antibodies against leptospires was 78.7% (MR1, 74.9 %; MR2, 84.1 %; and MR3, 80.2 %). Serogroup prevalence was different in each mesoregion evaluated and varied with vaccination status tested of the animals. The most prevalent serogroups in MR1 were Djasiman and Icterohaemorrhagiae. In MR2 and MR3, Djasiman was the most prevalent serogroup, regardless of vaccination status. Other prevalent serogroups in vaccinated animals were Icterohaemorrhagiae (MR1), Sejroe (MR2), Pomona, Sejroe, and Icterohaemorrhagiae (MR3). The other serovars tested had a prevalence of less or equal than 2%. The occurrence of reproductive problems with abortions and estrus repetition, was associated with reactivity to the serogroup Djasiman (P > 0.05). The results showed that the access of animals to flooded areas and the presence of rodents were significant risk factors, according to the literature.Discussion: The prevalence of antibodies against Leptospira in the studied areas was higher than expected, with a high prevalence of Djasiman serogroup. It is important to note that this serogroup is not present in current vaccine formulations. The presence of wetlands and rodents as risk factors in association with Djasiman is consistent with the scientific literature, since wild rodents are natural hosts, and swampy areas may allow Leptospira to survive for up to 180 days in the environment. Due to the presence and high prevalence found of the serogroup Djasiman in the experiment, new studies are being carried out to improve our knowledge about this serogroup and its possible inclusion in a commercial vaccine. Prophylaxis and control measures were recommended to rural producers in the analyzed properties.Keywords: bovine leptospirosis, herds, zoonosis, antibodies, reproductive disorders, leptospires, Djasiman.

Assessment of Serum Macrophage Migration Inhibitory Factor (MIF) as an Early Diagnostic Marker of Leptospirosis.

The search for valuable early diagnostic markers for leptospirosis is ongoing. The aim of the present study was to evaluate the diagnostic value of macrophage migration inhibitory factor (MIF) for leptospirosis. MIF is an immunoregulatory cytokine secreted by a variety of cell types involved in immune response and the pathogenesis of various diseases. It was previously described as a severity predictor of diseases. Samples of 142 leptospirosis cases, 101 other febrile cases, and 57 healthy controls were studied. The prevalence of leptospirosis was 47.3%. Autumnalis, Australis, and Canicola were the highly prevalent leptospiral serovars with a microscopic agglutination test (MAT) titer in the range 1:80–1:2,560. Enzyme-linked immunosorbent assay (ELISA) of MIF was carried out to measure the serum MIF levels. We found that the serum MIF levels [median, (interquartile range)] were significantly (p < 0.001) elevated in different clinical forms of leptospirosis, such as febrile illness [7.5 ng/ml (5.32–8.97)], pulmonary hemorrhage [13.2 ng/ml (11.77–16.72)], Weil’s syndrome [8.8 ng/ml (7.25–9.95)], and renal failure [8.6 ng/ml (7.18–10.5)], than in healthy controls [0.65n g/ml (0.5–1.1)]. Serum MIF had sensitivity, specificity, positive predictive value, and negative predictive value of 100%, >90%, >90%, and 100%, respectively. Receiver operating characteristic (ROC) analysis revealed that the serum MIF levels between leptospirosis cases and control subjects had an area under the curve (AUC) value of >0.9 (p < 0.0001). In leptospirosis patients, elevation of serum MIF was significantly (p < 0.001) higher in severe cases with organ dysfunction [10 ng/ml (7.8–14.5)] than that in mild febrile cases [7.5 ng/ml (5.32–8.97)], with the difference of 2.5 indicating that serum MIF acts as a predictor of leptospirosis severity. Pearson’s correlation test demonstrated that the serum MIF level was strongly correlated (r = 0.75, p < 0.0001) with disease progression. The median lethal dose (LD50) of leptospiral lipopolysaccharide (LPS) in BALB/c mice was determined to be 20 mg/kg, which gave rise to endotoxemia. Leptospiral LPS triggered the upregulation of MIF expression at 24 h post-infection, which reached the peak level at 24 h post-treatment in THP-1 cells and showed elevated MIF expressions in different tissues of BALB/c mice at the early stage of infection. Taken together, MIF is an early-phase cytokine that could serve as a rapid diagnostic marker for leptospirosis.

Development of a novel trivalent invasive non-typhoidal Salmonella outer membrane vesicles based vaccine against salmonellosis and fowl typhoid in chickens

Poultry animals act as natural reservoirs of invasive non-typhoidal Salmonella [iNTS] serovars and consumption of iNTS contaminated poultry meat and eggs is one of the major sources of iNTS infection in developed and developing countries. Irrational use of antibiotics in the poultry industry gives rise to the global emergence of multi drug resistant iNTS strains. Among different strategies to control iNTS infection in poultry farms, vaccination is now being widely used. There are several licensed vaccines available in the market for poultry animals to ameliorate iNTS infection but none of them have broad spectrum protective efficacy. In this study we have formulated a single novel trivalent iNTS outer membrane vesicles [OMVs] based immunogen which can confer long term broad spectrum protection against most prevalent iNTS serovars. We have isolated OMVs from Salmonella Typhimurium [ST], Salmonella Enteritidis [SE], and Salmonella Gallinarum [SG] and formulated the trivalent immunogen by mixing OMVs in a 1:1:1 ratio. One day old chicks were immunized thrice via oral route at two week intervals. Vaccination significantly induced serovar specific antibodies detected up to 180 days post immunization. Post challenge with both homologous and heterologous [S. Infantis] serovars, immunized birds showed reduced level of fecal shedding and organ invasion. A long term efficacy study also showed reduced levels of tissue invasion up to one year post immunization. These results demonstrate that our novel formulation of immunogen could be a broad spectrum potential vaccine for both layer and broiler breeds against iNTS mediated salmonellosis and fowl typhoid.

Seroprevalence of Leptospira Among Selected Mammals on a Wildlife Management Area in Louisiana, USA

From August to December 2018, we collected blood samples from 98 individuals of 11 mammal species to examine seroprevalence of leptospirosis at the Sherburne Wildlife Management Area in central Louisiana, US. Overall, 21.4% of individuals tested positive for antibodies of at least one Leptospira interrogans serovar and six individuals were reactive for two or more serovars. The most prevalent serovar we detected was serovar Bratislava (19.4%), followed by serovar Grippotyphosa (6.1%), serovar Icterohaemorrhagiae and serovar Pomona (2.0%), and serovar Canicola and serovar Hardjo (1.0%). We detected the highest prevalence in fox squirrels (Sciurus niger), hispid cotton rats (Sigmodon hispidus), and feral swine (Sus scrofa), with serovar Bratislava being the most reactive for these three species. Positive samples returned titer results of 100-400 for all species and serovars, with the exception of one feral swine that returned a titer of 1,600 to serovar Bratislava, indicating an active infection. Although the potential effects of leptospirosis on our study species remains unclear, our data contribute information necessary to understand and manage potential risks of Leptospira exposure to wildlife, domestic animals, and humans.

Clonal relatedness and antimicrobial susceptibility of Salmonella serovars isolated from humans and domestic animals in Iran: a one health perspective.

Salmonellosis is one of the most important zoonotic diseases in humans and animals worldwide. The main objective of this study was to report serovars, clonal relatedness, and antimicrobial resistance of Salmonella strains isolated from human, different animal hosts including pigeons, broilers, cattle, camel, parrots, and hamsters in different regions of Iran. Twenty-four Salmonella isolates were confirmed at the genus level by biochemical tests and polymerase chain reaction (PCR) by showing the presence of invA gene. Serovars were determined and their clonal relatedness was assessed by RAPD-PCR and antibiotic resistance profiles. Overall, Salmonella Typhimurium was the most prevalent serovar (45.8%, 11/24), which was recovered from humans, pigeons, and camels. Salmonella Enteritidis (29.2%, 7/24) was the second common serovar that was recovered from cattle, broilers, humans, and hamsters. Salmonella Infantis (12.5%, 3/24) belonged only to broiler sources, and Salmonella Seftenberg (12.5%, 3/24) was isolated from eggs and a parrot. The major RAPD pattern was VI (33.3%) in which the two S. Typhimurium isolates (belonged to humans and pigeons) exhibited similarity in both RAPD pattern and resistance profile. Antimicrobial susceptibility test showed full resistance to tylosin and erythromycin (100%, 24/24). All isolates (100%, 24/24) were susceptible to ceftriaxone, cefixime, and gentamicin. In total, 75% of the isolates were multi-drug resistant (MDR) and revealed 15 different antimicrobial resistance profiles (R-type). This study supports the potential transmission of Salmonella serovars via animal contacts. Thus, it is necessary to establish a national systematic monitoring program with one health approach for controlling Salmonella infections.

Analysis of Prevalent Leptospira Serovar in Different Animals of South Gujarat Region during the Year of 2020

Analysis of Prevalent Leptospira Serovar in Different Animals of South Gujarat Region during the Year of 2020

Antimicrobial susceptibility and molecular characterization of Salmonella enterica serovar Indiana from foods, patients, and environments in China during 2007–2016

Salmonella enterica serovar Indiana has become a widely prevalent non-typhoidal serovar in China in recent years. To improve the understanding of antimicrobial resistance and genetic bias in this emerging pathogen, a total of 214 S . Indiana isolates from foods, patients, and the environments in China from 2007 to 2016 were characterized for antimicrobial susceptibility, antimicrobial resistance-determining factors, and molecular typing. It was found that 208 (97.2%) exhibited resistance to ciprofloxacin, and 102 (47.7%) isolates to ceftriaxone. Ciprofloxacin resistance increased from 82.4% in 2007–2008 to 100.0% in 2015–2016. Ceftriaxone resistance increased from 29.4% in 2007–2008 to 47.1% in 2015–2016. In particular, the proportion of multidrug-resistant (MDR) S. Indiana isolates increased from 64.7% in 2007–2008 to 91.4% in 2015–2016. Mutations in the quinolone resistance determining region (QRDR) ( gyr A and par C), plasmid-mediated quinolone resistance (PMQR) genes [ aac(6’)-Ib-cr , oqx AB, qnr A, qnr S, qnr B and qep A], extended-spectrum beta-lactamase (ESBL) genes ( bla OXA , bla CTX-M , bla TEM , bla CMY and bla VEB ), and class I integrons were identified in these S. Indiana isolates, along with transposon units of ΔIS Ecp1 - bla CTX-M-65 -IS 903B , IS Ecp1 -IS Vsa5 - bla CTX-M-14 -IS 903B , and IS Ecp1 - bla CTX-M-55/15 -Δ orf 477. To our knowledge, the ESBL gene bla VEB was identified in Salmonella for the first time. Diverse plasmid types (IncHI2, IncN, IncA/C, IncFIB, IncI1 and IncFII) were identified in these isolates, among which IncHI2-type plasmid (49.1%) was the most common type in S . Indiana. Multilocus sequence typing (MLST) showed a single ST17 in S . Indiana. Pulsed-field gel electrophoresis (PFGE) results showed that there was a genotypic diversity, and some clones might have existed in S . Indiana between patients and foods for several years. These findings suggested that the frequent emergence of S . Indiana isolates with resistance to ciprofloxacin and ceftriaxone would pose a huge threat to food safety and public health. ∙ Ciprofloxacin and ceftriaxone co-resistant isolates were found. ∙ESBLs genes, PMQR genes with mutations in QRDR and class I integrons were observed. ∙ bla VEB was identified in Salmonella for the first time. ∙IS Ecp1 , IS Vsa5 and IS 903B was adjacent to bla CTX-M. ∙ST17 and genotypic diversity were identified in S. Indiana.

Diversity and antimicrobial resistance of Salmonella enterica serovars in surface river water and sediment

This study aimed to evaluate the contamination by Salmonella sp. in the Capinzal River, to determine the prevalent serovars, patterns of antimicrobial resistance, and the genetic relationships between the serovars identified. A total of 108 samples were collected from 2016 to 2018. The isolation of Salmonella spp. was conducted according to International Organization for Standardization (ISO) standards. The antimicrobial resistance profile of the Salmonella isolates was evaluated, and isolates were selected for serotyping and verification of genetic similarity using the Pulsed-Field Gel Electrophoresis (PFGE) Technique. Of the 108 samples collected, 35 (32.4%) were positive for Salmonella; 17.2% of the isolates were from the rural area; and 88.6% were from the urban area. Salmonella was isolated from all collect points along the river, with a higher incidence at the beginning of the urban area, indicating that contamination starts in the rural area and intensifies in the urban area of the city. A percentage of 35.1% of the Salmonella isolates were resistant to at least two antibiotics, while 18.9% were considered multidrug-resistant (resistant to at least two antibiotics of different classes). Seven serovars were distinguished from the serotyped isolates, with a prevalence rate of 23.5% for S. Infantis, S. Orion, and S. Javiana; 11.8% for S. Senfterberg, and 5.9% for S. Montevideo, S. Heidelberg, and S. enterica subsp. enterica (O: 6.8). The variability in specific restriction sites generated by PFGE resulted in 10 pulsotypes, separating mainly different serotypes.

Differences in antimicrobial resistance of Salmonella spp. isolated from humans, animals and food products in Kazakhstan

The aims of this study were twofold: 1. to isolate Salmonella spp. from different sources in Kazakhstan, to determine their serovars and resistance profiles and 2. to evaluate similarities in antimicrobial susceptibility of Salmonella spp. isolated from humans, animals and food products. From the10 212 samples tested Salmonella spp. Were isolated in 47 cases. The predominant serovar isolated from humans and food products was S. Enteritidis. Although different animal species were tested the Salmonella spp. were isolated mainly from chickens and ducks. S. Enteritidis and S. Typhimurium were the most prevalent serovars in raw poultry meat. The most frequent resistances were those to nalidixic acid, ampicillin and tetracycline. Human isolates demonstrated lower resistance compared to animal and food isolates. The genes encoding antimicrobial resistance in human isolates in most cases were absent except for some isolates which harboured tet, sul, stre and bla TEM genes encoding resistance to the oldest antimicrobial classes. The situation in animals and food products was less beneficial as besides different genes, integrons associated with the horizontal gene transfer were detected. The findings suggest that antimicrobials in animal sector should be used more strictly, paying attention to critically important antimicrobials for humans and possible horizontal transfer of pathogens and their genetic determinants.

Climate change, extreme events, and increased risk of salmonellosis: foodborne diseases active surveillance network (FoodNet), 2004-2014

BackgroundInfections with nontyphoidal Salmonella cause an estimated 19,336 hospitalizations each year in the United States. Sources of infection can vary by state and include animal and plant-based foods, as well as environmental reservoirs. Several studies have recognized the importance of increased ambient temperature and precipitation in the spread and persistence of Salmonella in soil and food. However, the impact of extreme weather events on Salmonella infection rates among the most prevalent serovars, has not been fully evaluated across distinct U.S. regions.MethodsTo address this knowledge gap, we obtained Salmonella case data for S. Enteriditis, S. Typhimurium, S. Newport, and S. Javiana (2004-2014; n = 32,951) from the Foodborne Diseases Active Surveillance Network (FoodNet), and weather data from the National Climatic Data Center (1960-2014). Extreme heat and precipitation events for the study period (2004-2014) were identified using location and calendar day specific 95th percentile thresholds derived using a 30-year baseline (1960-1989). Negative binomial generalized estimating equations were used to evaluate the association between exposure to extreme events and salmonellosis rates.ResultsWe observed that extreme heat exposure was associated with increased rates of infection with S. Newport in Maryland (Incidence Rate Ratio (IRR): 1.07, 95% Confidence Interval (CI): 1.01, 1.14), and Tennessee (IRR: 1.06, 95% CI: 1.04, 1.09), both FoodNet sites with high densities of animal feeding operations (e.g., broiler chickens and cattle). Extreme precipitation events were also associated with increased rates of S. Javiana infections, by 22% in Connecticut (IRR: 1.22, 95% CI: 1.10, 1.35) and by 5% in Georgia (IRR: 1.05, 95% CI: 1.01, 1.08), respectively. In addition, there was an 11% (IRR: 1.11, 95% CI: 1.04-1.18) increased rate of S. Newport infections in Maryland associated with extreme precipitation events.ConclusionsOverall, our study suggests a stronger association between extreme precipitation events, compared to extreme heat, and salmonellosis across multiple U.S. regions. In addition, the rates of infection with Salmonella serovars that persist in environmental or plant-based reservoirs, such as S. Javiana and S. Newport, appear to be of particular significance regarding increased heat and rainfall events.

Prevalence of anti-leptospiral antibodies and frequency distribution of Leptospira serovars in small ruminants in enzootic South Peninsular India

Background and Aim:For understanding the epidemiology of leptospirosis, the confined abundance of several species of pathogenic leptospires and knowledge on the serovar(s) prevalent in the reservoir and carrier hosts may be a useful indicator of transmission to incidental/accidental hosts in a geographical niche. The present study was carried out to ascertain the frequency distribution of Leptospira serovars and the prevalence of anti-leptospiral antibodies in small ruminants (sheep and goats) in the epidemiological units (villages) in the coastal districts of enzootic regions in South Peninsular India.Materials and Methods:A total of 1167 serum samples (sheep n=299 and goats n=868) from apparently healthy animals, randomly collected from various epidemiological units were tested in microscopic agglutination test (MAT) using 18 reference Leptospira serovars antigens.Results:The overall seroprevalence of 40% (at 95% confidence intervals [CI]: 36.82-42.43) in small ruminants (44% [95% CI: 40.49-52.26] in sheep and 38% [95% CI: 34.96-41.41] in goats) was observed with the predominance of Icterohaemorrhagiae, Javanica, Australis, Hurstbridge, and Pyrogenes serogroup anti-leptospiral antibodies in the studied region. The Chi-squared test revealed that the presence of anti-leptospiral antibodies is significantly not independent (associated) across the administrative division (Chi-square=105.80, p<0.05) as well as for sheep (Chi-square=34.67, p<0.01) and goats (Chi-square=68.78, p<0.01). Among seropositive samples (n=462 reactors), the MAT was positive for more than one serovar in 73% of sheep (95/131) and 53% of goats (177/331), representing an overall 59% cross-reactive prevalence in small ruminants. The determined frequency distribution (varied among small ruminants) of the employed serovars representing major reactive serogroup was Icterohaemorrhagiae (29.87), Javanica (20.78), Australis (20.35), Hurstbridge (16.23), Pyrogenes (15.8), Djasmin (15.58), Bataviae (15.37), Autumnalis (14.5), Canicola (14.5), Hebdomadis (14.07), Shermani (13.64), Panama (13.42), Sejroe (12.77), etc.Conclusion:This study indicates alarmingly high seroprevalence of leptospirosis in small ruminants with existing endemicity in the studied region in South Peninsular India. Further, these prevalent serovars in the administrative division may be of use in the reference panels of antigens in the MAT in both humans and animal disease diagnostic laboratories for effective and timely diagnosis of leptospirosis and to combat the challenges in public health.