Predominant Serotype Research Articles

Global Spread of MCR-Producing Salmonella enterica Isolates.

Colistin resistance in bacteria has become a significant threat to food safety and public health, and its development was mainly attributed to the plasmid-mediated mcr genes. This study aimed to determine the global prevalence and molecular characteristics of mcr-producing Salmonella enterica isolates. A total of 2279 mcr-producing Salmonella genomes were obtained from the public database, which were disseminated in 37 countries from five continents worldwide, including Asia, Europe, America, Australia, and Africa. Human samples (39.5%; 900/2279) were the predominant sources of mcr-producing Salmonella isolates, followed by foods (32.6%), animals (13.7%), and environment (4.4%). Furthermore, 80 Salmonella serotypes were identified, and Typhimurium and 1,4,[5],12:i:- were the predominant serotypes, accounting for 18.3% and 18.7%, respectively. Twenty mcr variants were identified, and the most common ones were mcr-9.1 (65.2%) and mcr-1.1 (24.4%). Carbapenems-resistance gene blaNDM-1 and tigecycline-resistance gene tet(X4) were identified in one isolate, respectively. Phylogenetic results indicated that mcr-producing Salmonella fell into nine lineages (Lineages I-IX), and Salmonella Typhimurium, 1,4,[5],12:i:- and 4,[5],12:i:- isolates from different countries were mixed in Lineages I, II and III, suggesting that international spread occurred. These findings underline further challenges for the spread of Salmonella-bearing mcr genes.

Genomic features of predominant non-PCV13 serotypes responsible for adult invasive pneumococcal disease in Spain.

Although pneumococcal conjugate vaccines (PCVs) effectively prevent invasive pneumococcal disease (IPD), serotype replacement has occurred. We studied the pangenome, antibiotic resistance mechanisms and presence of mobile elements in predominant non-PCV13 serotypes causing adult IPD after PCV13 vaccine introduction in Spain. We conducted a multicentre study comparing three periods in six Spanish hospitals and analysed through whole genome sequencing representative strains collected in the pre-PCV13, early-PCV13 and late-PCV13 periods. Among 2197 cases of adult IPD identified, 110 pneumococci expressing non-PCV13 capsules were sequenced. Seven predominant serotypes accounted for 42.6% of IPD episodes in the late-PCV13 period: serotypes 8 (14.4%), 12F (7.5%), 9N (5.2%), 11A (4.1%), 22F (3.9%), 24F (3.9%) and 16F (3.6%). All predominant non-PCV13 serotypes were highly clonal, comprising one or two clonal complexes (CC). In general, CC538, CC4048, CC3016F, CC43322F and CC669N, related to predominant non-PCV13 serotypes, were antibiotic susceptible. CC15611A was associated with resistance to co-trimoxazole, penicillin and amoxicillin. CC23024F was non-susceptible to penicillin and resistant to erythromycin, clindamycin, and tetracycline. Six composite transposon structures of the Tn5252-family were found in CC23024F, CC98912F and CC3016F carrying different combinations of erm(B), tet(M), and cat. Pangenome analysis revealed differences in accessory genomes among the different CC, with most variety in CC3016F (23.9%) and more conservation in CC15611A (8.5%). We identified highly clonal predominant serotypes responsible for IPD in adults. The detection of not only conjugative elements carrying resistance determinants but also clones previously associated with vaccine serotypes (CC15611A and CC23024F) highlights the importance of the accessory genome.

Isolation, Molecular Characterization, and Antibiotic Resistance of Avian Pathogenic Escherichia coli in Eastern China.

Avian pathogenic Escherichia coli (APEC) causes colibacillosis in avians, resulting in considerable losses in the poultry industry. APEC showed zoonotic potential initially related to the fact that APEC serves as the reservoir of virulence genes and antibiotic resistance genes for other E. coli. Thus, we determine the serotypes, phylogenetic groups, virulence genes distribution, and antibiotic resistance profiles of APEC isolates in eastern China. A total of 230 APEC were isolated from diseased chicken and duck with typical colibacillosis symptoms. Serotyping identified that O78 (44.78%) was the predominant serotype. The majority of APEC isolates were classified into B2 (29.57%), A (26.96%), D (20.00%), and B1 (18.26%), respectively. Among the 15 virulence genes, a high prevalence of ibeB (99.57%), fimC (91.74%), mat (91.30%), ompA (83.04%), and iss (80.43%) genes was observed. Except for low resistance rates for imipenem (1.7%) and polymyxin B (0.4%), most of the APEC isolates were resistant to erythromycin (98.7%), enrofloxacin (96.1%), tetracycline (95.2%), doxycycline (93.9%), lincomycin (90.0%), and streptomycin (90.0%). Moreover, all APEC exhibit multi-drug resistance. This study indicated that APEC isolates harbor a variety of virulence genes and showed multi-antibiotic resistance profiles, providing proof for understanding the epidemiological background and zoonotic potential of APEC in poultry farms.

Lam aglütinasyon metodu ile bakteriyel balık hastalıklarının teşhisi ve serotiplerin sınıflandırılması

Bacterial fish pathogens cause significant losses in rainbow trout farms. In fish farms, bacterial pathogens cause threatening diseases which has made it necessary to develop rapid methods for disease diagnosis. Serological techniques which are applied with a small amount of antiserum and sample, are preferred for the rapid diagnosis of fish diseases. In this study, formalin-killed antigens prepared from reference strains of Lactococcus garvieae, Yersinia ruckeri, and Vibrio (Listonella) anguillarum were injected intravenously in consecutive doses to New Zealand rabbits. One week after the last injection, the sera separated to use in the slide agglutination tests. A total of 42 strains were studied, including Y. ruckeri (18 isolates), V. anguillarum (14 isolates), and L. garvieae (7 isolates) and 3 references (ATCC 43305, ATCC 29473, ATCC 49156) strains. Serotype O1 determined the predominant serotype (86%) in V. anguillarum and Y. ruckeri (84%) strains examined by the slide agglutination method. L. garvieae strains did not react against Japanese antisera but positively reacted against Turkish L. garvieae antisera.

Phenotypic and genomic characterization for Salmonella isolates recovered from meat products in Beijing wholesale markets, 2014-2015

Objective: To analyze the phenotypic and genomic characteristics of Salmonella isolates recovered from meat products in Beijing wholesale markets. Methods: A total of 336 Salmonella strains from meat products collected from wholesale markets in Beijing were tested for antimicrobial resistance to 25 antimicrobial compounds by micro-broth dilution method; whole genome data were sequenced, followed by the serotype and ST type prediction by Seqsero2 and SISTR software, and the drug resistance genes and virulence factors were also predicted with CARD and VFDB databases of Abricate software; Salmonella serotyping assay kit and serum agglutination method were used for serotype confirmation of some isolates with different genome prediction results. Results: The resistance rates to Nalidixic acid and Ampicillin were 62.5% (210/336) and 55.1% (185/336), respectively, and all isolates were susceptible to Tigecyclin, Cefoxitin and Carbapenem antimicrobial compounds; 207 isolates (61.6%, 207/336) were multi-drug resistant, some could even be resistant to ten categories of drugs at the same time, and the most common antimicrobial resistance spectrum was NAL-AMP-SAM. A total of 24 serotypes were detected with predominant serotypes of Enteritidis (34.5%, 116/336), Derby (17.3%, 58/336) and Indiana (10.4%, 35/336). A total of 27 ST types were detected, the dominant type was ST11; ST types were in good consistency with serotypes; The detection rates of resistant genes referred to aminoglycosides, fluoroquinolones, β-lactams, sulfonamides and tetracyclines are more than 48%, and the first two reached 100%. The prediction of drug resistance genes was consistent with the results of antimicrobial resistance phenotype. A total of 122 virulence genes were predicted, 74 of which existing among all isolates. Conclusion: Salmonella in meat from the wholesale markets of Beijing has a high proportion of multiple drug resistance, a complex drug resistance spectrum, a variety of serotypes and ST types, and a high carrying rate of drug resistance gene and virulence gene; drug resistance phenotype and genotype are relatively consistent.

Molecular Characterization of Predominant Serotypes, Drug Resistance, and Virulence Genes of Streptococcus pneumoniae Isolates From East China

Streptococcus pneumoniae is a common diplococcus pathogen found worldwide. The characterization of predominant serotypes, drug resistance, and virulence genes of S. pneumoniae isolates prevailing in different areas and countries is clinically important for choice of antibiotics and improvement of vaccines. In this study, pneumonia (78.7%) and meningitis (37.0%) were the predominant diseases observed in the 282 (children) and 27 (adults) S. pneumoniae-infected patients (p < 0.05) from seven hospitals in different areas of East China. Of the 309 pneumococcal isolates, 90.3% were classified by PCR into 15 serotypes, with serotypes 19F (27.2%) and the 6A/B (19.1%) being most predominant (p < 0.05). Importantly, serotypes 15A and 15B/C combined for a total of 10.4% of the isolates, but these serotypes are not included in the 13-valent pneumococcal capsule conjugate vaccine used in China. Antimicrobial susceptibility analysis by the E-test showed that >95% of the 309 pneumococcal isolates were susceptible to moxifloxacin and levofloxacin, as well as 18.4, 85.8, and 81.6% of the isolates displayed susceptibility to penicillin, cefotaxime, and imipenem, respectively. A significant correlation between the prevalence of predominant serotypes and their penicillin resistance was observed (p < 0.05). In particular, >95% of all the pneumococcal isolates showed resistance to erythromycin and azithromycin. Of the nine detected virulence genes, the lytA, ply, hysA, and nanA were the most common with 95–100% positive rates in the 309 pneumococcal isolates, while the pavA and psaA genes displayed a significant correlation with pneumococcal bacteremia and meningitis (p < 0.05). Overall, our data suggested that the predominant serotypes, drug resistance, and virulence genes of the S. pneumoniae isolates prevailing in East China are distinct from those observed in other areas of China and adjacent countries.

Characterization of Uropathogenic Pseudomonas aeruginosa: Serotypes, Resistance Phenotypes, and Virulence Genotypes

Pseudomonas aeruginosa is a major cause of urinary tract infections. This organism has extended resistance to antimicrobials along with multiple virulence factors, making it difficult to treat. In this study, 49 isolates from urine samples were identified as P. aeruginosa and serotyped by the slide agglutination method. The sensitivity of isolates against 10 antipseudomonal drugs was determined. Phenotypically, lipase, protease, hemolysin, and biofilm production were detected. Genes for the type III secretion system, elastase B, and exotoxin A were detected by PCR. Serotype O11 was the most predominant serotype among test isolates. High levels of resistance were observed against ceftazidime, cefepime, piperacillin, and piperacillin/tazobactam while 10.2% of isolates were resistant to amikacin. MDR was detected in 20.4% of the isolates and was significantly associated with strong biofilm producers. About 95.9% and 63.3% of P. aeruginosa isolates had proteolytic and lipolytic activity, respectively. Among the genes detected, the exoY gene was the most prevalent gene (79.6%), while the exoU gene was the least frequent one (10.2%). toxA and lasB genes were amplified in 63.27% and 75.5% of the isolates, respectively. In addition, the exoU gene was significantly associated with MDR isolates. The high incidence of exoS, exoT, exoY, lasB, and toxA genes in uropathogenic P. aeruginosa implies that these genes can be considered markers for virulent isolates. Furthermore, the coexistence of exoU and exoS genes, even in 6% of isolates, poses a significant treatment challenge because those isolates possess both the invasive and cytotoxic properties of both effector proteins.

Emergence and predominance of a new serotype of Vibrio parahaemolyticus in Huzhou, China

BackgroundDuring our surveillance period, we found a new type of Vibrio parahaemolyticus (V. parahaemolyticus) with serotype O10:K4, which had increased over the past 2 years in Huzhou and became the second most common serotype after O3:K6. MethodsStrains were isolated from stool samples of diarrhea patients in the First People's Hospital in Huzhou. The serotypes, virulence-associated genes, antimicrobial susceptibility, and pulsed field gel electrophoresis (PFGE) of these strains were analyzed. ResultsBetween January 2017 and December 2021, there were 598 (5.36%) V. parahaemolyticus-positive samples of 11,166 stool specimens. The V. parahaemolyticus detection rate was high in summer months. The O3:K6 was the dominant serotype in 2017–2020 and a new serotype, O10:K4, was the predominant serotype in 2021. The majority of isolates tested were resistant to ampicillin (86.8%). We randomly chose the strains with serotype O3:K6 and O10:K4 for PFGE to compare the genetic relationship between these two serotypes. The results showed that the PFGE profiles of V. parahaemolyticus O3:K6 and O10:K4 were genetically similar. The strains showed a tendency to cluster on the basis of their serotype profiles. However, some O3:K6 strains showed 100% similarity with O10:K4 strains. ConclusionA new serotype with pandemic potential of V. parahaemolyticus, O10:K4, was detected in 2020 and became dominant in 2021 in Huzhou.

Epidemiology and long-term neurological sequelae of childhood herpes simplex CNS infection.

AimHerpes simplex CNS infection is a rare but important cause of neurological disability. Long term outcomes after HSV CNS infection in Australia have not yet been fully described. We sought to provide a comprehensive review of HSV CNS infection in children using a retrospective 13‐year evaluation of statewide laboratory and clinical records and a parent survey conducted at least one year after the initial infection.MethodsAll positive PCR HSV 1 and 2 results from cerebrospinal fluid (CSF) or brain tissue were obtained from Queensland pathology providers for children aged 0–16 years between 1 January 2005 and 31 December 2017. Clinical data were obtained from patient records and longer‐term outcomes via parent survey at least 1 year after initial infection.ResultsForty‐three children were identified over the 13‐year period, 17 (39.5%) neonates and 26 (60.4%) non‐neonates. The annual incidence for HSV CNS infection in Queensland children aged ≤16 years was 0.3/100 000 (95% confidence intervals (CIs): 0.2–0.4) with neonates at highest risk (incidence 2.5/100 000 live births, 95% CI: 1.5–3.9). HSV 1 was the predominant serotype in both neonates and non‐neonates (9/17, 52.9% neonates and 19/26, 73.1% non‐neonates). Seven (16.3%) children died, five (5/17, 29.4% neonates), directly attributable to HSV CNS infection (all neonates). Twenty‐five (58.1%) had neurological morbidity at discharge (9/17 neonates (52.9%) vs. 16/26 (61.5%) non‐neonates) and 20/27 (74.1%) reported long‐term neurological morbidity at follow‐up (5/9 neonates (55.6%) vs. 15/18 non‐neonates (83.3%)). Seven children (two neonates and four non‐neonates) with long‐term neurological sequelae had no neurological morbidity identified at discharge.ConclusionSignificant long‐term neurologic sequelae were seen in children with HSV CNS infection even in children with no neurological disability identified at discharge from hospital. Careful neurodevelopmental follow‐up of all children is recommended.

Prevalence and antimicrobial resistance of Salmonella in conventional and no antibiotics ever broiler farms in the United States

Non-typhoidal Salmonella is the second most common bacterial cause of foodborne illness in the United States. More than 50% of the poultry meat sold in the U.S. is categorized as no antibiotics ever (NAE), yet it is unclear how these practices affect the prevalence and antimicrobial resistance (AMR) of Salmonella . The aim of this study was to evaluate and compare the prevalence of Salmonella and the incidence of AMR in conventional (n=2) and NAE (n = 2) broiler farms in the Southeast US. Broiler cecal (n = 420) and ileal contents (n = 420), along with litter (n = 24), feed (n = 24) and water (n = 24) samples were collected from four broiler farms. Sample collection was carried out during a full production cycle and following the birds to the processing facilities. The BAX® Real-Time PCR system was used to detect Salmonella positive samples. Phenotypic antimicrobial susceptibility was evaluated following the National Antimicrobial Resistance Monitoring System (NARMS) method, and whole genome sequencing (WGS) was carried out for screening of AMR genes. The software tool SeqSero2 and the McOutbryk SNP calling pipeline were used for serotype identification and phylogenetic analysis, respectively. Conventional broilers had the highest Salmonella prevalence (80% and 73%; P ≤ 0.05) at day 21. The Salmonella prevalence declined as the birds aged. Antimicrobial resistance among Salmonella isolates from all sample types was high in all four farms (76%), exhibiting frequent resistance to tetracycline (76%) and streptomycin (70%). Salmonella isolates recovered from NAE broilers carried higher (P ≤ 0.05) rates of AMR than isolates from conventionally raised chicken. Salmonella enterica serotype Kentucky was the predominant serotype, harboring genes tet(B), aph(3″)-Ib and aph(6)-Id (which encode resistance to tetracycline and streptomycin, respectively). Farm-related strains of the serotype were identified, exhibiting persistence in the litter environment. • Broilers from NAE farms had lower Salmonella prevalence in the Southeast US. • Resistance to tetracycline and streptomycin among Salmonella was widespread. • Salmonella Kentucky was the predominant serotype on farms in the Southeast US. • Phylogeny of S. Kentucky strains exhibited farm-specific association. • Antimicrobial resistant genes tet(B), aph(3″)‐Ib , aph(6)‐Id and fosA7 were found.

Epidemiological and clinical characteristics of the foot and mouth disease outbreaks in cattle in central Ethiopia

Foot and mouth disease (FMD) is an acute highly contagious viral disease of all cloven-hoofed animals that causes significant economic problems in Ethiopia. The objectives of this study were to assess the morbidity and clinical features of FMD in sick cattle and identify causal serotypes of FMD outbreaks in central Ethiopia. Outbreaks of FMD were investigated in a total of 150 herds of cattle from January 2021 to April 2021. Seven epithelial tissue and 23 oral swab samples were collected and subjected to a real-time polymerase chain reaction (rRT-PCR) and Sandwich Enzyme-linked Immunosorbent Assay (ELISA) for detection and serotyping of FMD virus, respectively. A total of 150 herds of cattle were examined, of which 114 (76%) herds of cattle were clinically affected with FMD. In this study, 75.9% animal-level morbidity was recorded. Exotic breeds and adult cattle were more affected by Foot and Mouth Disease Virus (FMDV) with morbidity of 100% and 77.4%, respectively. The clinical features in sick cattle showed that profuse salivation was the most frequently observed clinical sign (40%) followed by oral cavity vesicle formation (30%), and interdigital space lesion (15%). Out of 30 samples subjected to rRT-PCR and ELISA test, 28 (93.33%) and 27 (90%) samples were found positive, respectively. In this study, three types of FMD serotypes were detected in which SAT-2 (n = 13) was the predominant serotype followed by serotype O (n = 9), and serotype A (n = 5). The current study revealed that FMD serotype SAT-2 was highly responsible for the occurrence of FMD outbreaks in central Ethiopia. Although the FMD vaccine produced in Ethiopia contains all the identified serotypes, detailed studies on topotypes identification have to be performed to provide full protection.

Comparative Genomics Applied to Systematically Assess Pathogenicity Potential in Shiga Toxin-Producing Escherichia coli O145:H28.

Shiga toxin-producing Escherichia coli (STEC) O145:H28 can cause severe disease in humans and is a predominant serotype in STEC O145 environmental isolates. Here, comparative genomics was applied to a set of clinical and environmental strains to systematically evaluate the pathogenicity potential in environmental strains. While the core genes-based tree separated all O145:H28 strains from the non O145:H28 reference strains, it failed to segregate environmental strains from the clinical. In contrast, the accessory genes-based tree placed all clinical strains in the same clade regardless of their genotypes or serotypes, apart from the environmental strains. Loss-of-function mutations were common in the virulence genes examined, with a high frequency in genes related to adherence, autotransporters, and the type three secretion system. Distinct differences in pathogenicity islands LEE, OI-122, and OI-57, the acid fitness island, and the tellurite resistance island were detected between the O145:H28 and reference strains. A great amount of genetic variation was detected in O145:H28, which was mainly attributed to deletions, insertions, and gene acquisition at several chromosomal “hot spots”. Our study demonstrated a distinct virulence gene repertoire among the STEC O145:H28 strains originating from the same geographical region and revealed unforeseen contributions of loss-of-function mutations to virulence evolution and genetic diversification in STEC.

Design of an Epitope-Based Peptide Vaccine Against Dengue Virus Isolate from Eastern Uttar Pradesh, India.

Dengue outbreaks are a serious public health concern that occurs on a regular basis in various locations of India. According to the Government of India's National Center for Vector-Borne Disease Control, a total of 1,23,106 dengue cases were identified in India as of October 2021. The currently available dengue vaccine was found to be ineffective against all serotypes of the virus. Dengue virus serotype 2 was reported to be the sole predominant serotype in Eastern Uttar Pradesh, India. An epitope-based peptide vaccine is believed to be safe and effective against all serotypes of the dengue virus. In this work, an epitope-based peptide vaccine based on envelope protein against the dengue virus was developed using the reverse vaccinology method. T-cell epitopes present in the envelope protein were screened using different immunoinformatic tools. Epitopes predicted by all servers were chosen and additionally picked out on the grounds of their antigenic reactivity, immunogenicity, toxicity, and allergenicity assessment. Three potent T cell epitopes as IVQPENLEY, ILIGVVITW, and DTAWDFGSL were screened, which binds with HLA-B*35:01, HLA-B*58:01, HLA-A*26:01 alleles, respectively. To build a 3D structure model of epitopes and alleles, the PepstrMod and Swiss-Model servers were used. Predicted epitopes and HLA alleles were docked using the HPEPDOCK server to confirm binding ability. These anticipated epitopes were found to cover the greatest number of populations in India and around the world. These identified epitopes have a high potential for eliciting an immune response in the development of a vaccine against the dengue virus, while further experimental validation is required for final confirmation.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10989-022-10402-4.

Molecular detection of dengue virus serotypes prevalent in central Kerala and its correlation with disease severity

Dengue is the most important mosquito-borne viral disease in the world. In 2017, a concerning increase in dengue cases with high mortality was seen in India with Kerala topping the list. Changing pattern of circulating dengue virus serotype and co infection with multiple serotypes contribute to the increasing trend in severity and increased mortality of dengue fever. The present study focused to find the dengue serotypes prevalent in central Kerala and prevalence of co infection with multiple serotypes here with an attempt to correlate these with clinical severity of dengue: This descriptive study was done in the Microbiology department of Jubilee Mission Medical College, Thrissur for a period of 18 months. Blood samples of clinically suspected dengue fever cases which were positive for NS1 antigen and having fever not more than 5 days were subjected to molecular methods to detect dengue virus RNA followed by multiplex RTPCR to find its serotype. Demographic features, clinical details and lab parameters were also collected from each patient. A total of 108 samples positive for Dengue NS1 antigen were subjected to RT-PCR. Among them 61(56.5%) were positive by RT-PCR. All the 4 Dengue serotypes were found with DENV-2 with 30 cases (49.2%) being the predominant serotype followed by DENV-1 with 20 cases (32.8%), DENV-3 with 12 cases (19.6%) and DENV-4 with 2 cases (3.27%). Three cases (4.9%) of co infection with DENV-1,2, DENV-1, 4 and DENV-2,3 were also found. Two among the 108 patients (1.85%) died in the present study. Significant correlation between severity of dengue infection and serotypes could not be found due to very few severe cases encountered during the study. : The dengue serotypes predominant in central Kerala is DENV-2. The prevalence of co infection with multiple serotypes is 4.9% which proves that this area has become hyper endemic to the disease, which increases the risk of emergence of more severe cases.

Incidence of lab-confirmed dengue fever in a pediatric cohort in Delhi, India.

Our aim was to estimate the overall and age-specific incidence of lab-confirmed dengue fever using ELISA based assays among children 6 months to 15 years in Delhi. We enrolled a cohort of 984 children aged 6 months to <14 years in South Delhi and followed-up weekly for fever for 24 months or till 15 completed years of child-age. Households of the enrolled children were geo-tagged. NS1, IgM and IgG assays were conducted using ELISA method to confirm dengue fever in children with ≥3 consecutive days of fever. Molecular typing was done in a subset of NS1 positive cases to identify the circulating serotypes. We had a total of 1953 person-years (PY) of follow up. Overall, there were 4208 episodes of fever with peaks during June to November. The overall incidence (95%CI) of fever was 215/100 PY (209 to 222). A total of 74/1250 3-day fever episodes were positive for acute dengue fever (NS1 and/or IgM positive). The overall incidence (95%CI) of acute dengue fever was 37.9 (29.8 to 47.6) per 1000 PY; highest among children aged 5 to 10 years (50.4 per 1000 PY, 95% CI 36.5 to 67.8). Spatial autocorrelation analysis suggested a clustering pattern for the dengue fever cases (Moran's Index 0.35, z-score 1.8, p = 0.06). Dengue PCR was positive in 16 of the 24 specimens tested; DEN 3 was the predominant serotype identified in 15/24 specimens. We found a high incidence of dengue fever among under 15-year children with clustering of cases in the community. DEN 3 was the most commonly circulating strain encountered. The findings underscore the need for development of affordable pre-vaccination screening strategy as well as newer dengue vaccines for young children while continuing efforts in vector control.

Epidemiological characteristics and serotype distribution of culture-confirmed pediatric pneumococcal pneumonia before and after PCV 10 introduction, a multicenter study in Bogota, Colombia, 2008–2019

BackgroundPneumococcal conjugate vaccines (PCVs) have decreased pneumonia in children. Colombia introduced mass vaccination with PCV10 in 2012. MethodsCases of pneumococcal pneumonia from 10 hospitals were included. Two periods were compared: pre-PCV10: 2008–2011 and post-PCV10: 2014–2019. The objective was to compare epidemiological and clinical characteristics before and after PCV10 vaccination. ResultsA total of 370 cases were included. Serotypes 1 (15, 11.2%) and 14 (33, 24.6%) were the most frequent in the pre-PCV10 period, with only 4 (3%) cases of serotype 19A and 1 case (0.7%) serotype 3. From the pre-PCV10 period to the post-PCV10 period, cases of serotypes 1 (6, 3.1%) and 14 (1, 7.8%) decreased, while cases of serotypes 19A (58, 30.2%), serotype 3 (32, 16.7%) and 6A (7, 3.6%) increased (p < 0.001); complicated pneumonia (CP) increased significantly (13.4% to 31.8%) (p < 0.001); hospitalizations increased from 8 (5.5–15) to 12 (7–22) days (p < 0.001); and the frequency of PICU admission increased from 32.8% to 51.6% (p = 0.001). The use of ampicillin-sulbactam (0.7% to 24%) and ceftriaxone/clindamycin (0.7% to 5.7%) increased in the post-PCV10 period. The duration of empirical antibiotic treatment was 7 (4–11) days in the pre-PCV10 period and increased to 10 (6–17) days (p < 0.001) in the post-PCV10 period. Lethality showed a slight nonsignificant increase (7.5% vs. 9.9%; p = 0.57) in the post-PCV10 period. ConclusionsPCV10 significantly decreased cases of serotypes 1 and 14, with an increase in cases of serotypes 19A, 3 and 6A, which were the predominant serotypes and had greater severity (e.g., admission to the PICU, CP and more resistance, with an increase in the use of broad-spectrum antibiotics and longer hospitalization) and subsequently included in PCV13. Current data support national and regional evidence on the importance of replacing PCV10 with a higher valence that includes 19A, such as PCV13, with the aim of reducing circulation, particularly of this serotype.

Isolation and Molecular Identification of Avian Pathogenic Escherichia coli in Broiler Chickens Suffering from Colibacillosis in some Governorates in Egypt

This study aimed to evaluate the most predominant strain of avian pathogenic Escherichia coli (APEC) that causes colibacillosis with respiratory manifestation in broiler chickens. Isolation and serotyping identification for the isolates of E. coli were performed. Prevalence of APEC differentiated by detection of the 8 virulence-associated genes “astA, iss, irp2, papC iucD, tsh, vat, and cva/cvi” using multiplex PCR technique in the most important isolates of E. coli was also investigated. Antibacterial sensitivity test for antibiotics disc and oregano at different concentrations (20%, 15%, 10%, and 5%), were estimated for the most important isolates of E. coli. A total of 50 broiler farms were located in Gharbia, Giza, Menoufia, Bahaira, and Dakahliah Governorates were examined. Specimens from lung, liver, spleen, and kidney from diseased birds were used for bacteriological examination. Results revealed that E. coli O27 was the most predominant serotype strain (11 out of 35 isolates), followed by the serotypes of O146 (4/35), O Untypable serotypes (4/35), and the (1/35) of each serotype of O8, O20, O44, O78, O114, O125, O142, O152, O153, O158, O164, and O166. One isolate of APEC O27 out of 11 isolates has 6 virulence-related genes “astA, iss, papC, iucD, vat, and cva/cvi”. Difloxacin and oregano at a concentration of 20% have the highest percentage (100%) of sensitivity against 11 isolates of E. coli O27 strains. In conclusion, E. coli O27 was the most predominant serotype infecting farms of broiler chickens. Difloxacin and oregano 20% could be used for the treatment of APEC O27.

Molecular characterization and antimicrobial resistance profile of pathogenic Escherichia coli from goats with respiratory disease in eastern China

Pathogenic Escherichia coli (E. coli) can cause a variety of intestinal and extra-intestinal infections in humans and animals. Similar with the intestinal disease, respiratory disease is also a major threat to the breeding industry of goats. But the reports on respiratory disease associated E. coli are very limited. In this study, E. coli and other pathogens were examined for the 77 submitted respiratory cases. The serotypes, virulence genes, phylogenetic group and antimicrobial resistance characteristics of the E. coli isolates were identified. The results showed that 34 cases (44.16%) were associated with E. coli and 22 cases showed mixed infections of E. coli with Mycoplasma ovipneumoniae, Mannheimia haemolytica or Pasteurella . Among the 49 E. coli isolates, O8 (32.65%), O9 (20.41%) and O89 (10.20%) were the predominant serotypes (31/49, 63.27%). 22 virulence genes were detected and the most prevalent genes were fimH (100%), yijp (100%), mat (97.96%), ompA (95.92%) ibeB (91.84%) and fyuA (77.55%). In addition, ibeA was detected in 6.12% (3/49) of the strains. Markers of extra-intestinal pathogenic E. coli (ExPEC) were also identified and 14 strains were classified as ExPECs. 14 (28.57%), 25 (51.02%), 3 (6.12%) and 7 (14.29%) strains belonged to phylogenetic group A, B1, B2 and D, respectively, and group A and B1 were the predominant ones. The E. coli strains showed high resistant (48.98%–100%) to the 14 selected antimicrobials and all of them were defined as multiple drug resistant (MDR) strains. This is the first systemically study on E. coli of goats respiratory diseases origin in eastern China. The results suggest that E. coli infection may play an important role in goat respiratory diseases and that goats are reservoir hosts of ExPECs, which needs continuous monitoring in the future.

Carrier status of Streptococcus suis in the palatine tonsils of apparently healthy slaughtered pigs of India

ABSTRACT Streptococcus suis is an emerging bacterial pathogen of huge economic impact to the swine industry worldwide. The information regarding the carrier status of S. suis in the slaughtered pigs along with its genetic characterization is not available in Indian pig population, which needs to be addressed for the therapeutic and preventive measures. In the present study, 563 palatine tonsils of apparently healthy slaughtered pigs were probed for the prevalence, and genetic characterization of S. suis and prevalence were found to be 15.45% and 32.68% by bacteriological and molecular methods, respectively. In 87 isolates recovered, 6 cps-types were detected showing the predominance of serotype 7 (24.13%) and 5 (18.39%), whereas 11 cps-types were detected in tonsillar DNA involving cps-types 9 (28.26%) and 7 (14.13%) as the major serotypes with arcA+/sly+/epf+/mrp− being the prevalent genotype. The histopathological changes with the immunodetection of S. suis antigen confirmed its persistence in asymptomatic carriers. Of 87 bacterial isolates, 7 isolates (serotypes 7 & 2) were pathogenic to Swiss albino mice showing the classical lesions of meningitis and septicemia. The presence of virulent serotypes of S. suis in healthy slaughtered pigs suggests a great health risk to the people engaged in piggery operations and in-contact pigs.

Changing serotypes of hand, foot and mouth disease in Shanghai, 2017\u20132019

BackgroundHand, foot, and mouth disease (HFMD) is a common reportable infectious disease that is highly contagious among children in China. This study aimed to characterize the epidemics of HFMD and the serotypes of enterovirus (EV) after the introduction of EV-A71 vaccines in Shanghai, a city in Eastern China.ResultsA total of 2271 HFMD cases were recruited in this study from May 2017 through October 2020. Among these cases, a male-to-female ratio of 1.6:1 was observed, and the cases were mainly in 1–4 years old (63.1%). Children of all ages had a relatively similar time span between the onset of HFMD and the initial medical visit (P = 0.5192). The cases were reported year-round with peaks in the summer (2018 and 2019) and fall (2017), which was consistent with previous epidemics of the reported HFMD cases in the Shanghai municipality. Among the specimens that tested positive for EV (n = 1855), CV-A6 was predominantly detected (71.1%), followed by CV-A16 (14.2%) and EV-A71 (7.0%). Notably, the number of HFMD cases infected with EV-A71 increased in 2019. Furthermore, 9.2% of the cases had comorbidities, mostly convulsion, bronchopneumonia, and pneumonia; however, they were not correlated with the EV serotypes. In addition, 31.2% (709/2271) of the cases were vaccinated with EV-A71 vaccines. The time span differed significantly between the time of vaccination and the onset of the disease across the groups based on whether the onset was before or after vaccination (P < 0.001).ConclusionsCV-A6 is the predominant EV serotype in the epidemic of HFMD in Shanghai; in addition, CV-A16 and EV-A71 may be moderately prevalent. The changing trends in the presence of EV serotypes contributes to the periodicity of the HFMD epidemic. In addition, the minority of HFMD cases may have comorbidities, regardless of the EV serotype. The use of the EV-A71 vaccine has affected the HFMD epidemic. And serotype-specific protection by the EV-A71 vaccine may promote vaccination in children infected with EV-A71 compared to those infected with non-EV-A71 serotypes, which would further change the epidemic scenario of HFMD.