Multidrug Resistance and Serotype Distribution of Salmonella Enterica Isolated from Homemade Recipe Fermented Ground Pork (Nham) in Northeastern Thailand

Salmonellosis is caused by a thousand serotypes of Salmonella enterica. The sour taste inherent to Nham leads people believe that this fermented ground pork dish is safe from pathogenic microorganisms. The aim of this study was to evaluate the prevalence, serotype, drug susceptibility, and antimicrobial resistance (AMR) genes of Salmonella spp. in homemade recipes of Nham. There were 52 samples from different Nham makers in 3 northeastern provinces of Thailand collected between August and November 2019. Further, 30 Salmonella isolates (57.7 %) and 14 different serovars were identified: S. Rissen (23.3 %) was the most prevalent, followed by S. Typhimurium (16.7 %), S. Give and S. Virchow (10 % each), and S. Agona and S. Kouka (6.7 % each). All isolates carried AMR genes but 7 (23.3 %) were antibiotic susceptible and 23 (76.7 %) borne a resistance phenotype. The Salmonella isolates were resistant to tetracycline (63 %), sulfamethoxazole/trimethoprim (36.7 %), streptomycin (33.3 %), nalidixic acid (30 %), cefotaxime (16.7 %), and enrofloxacin (3.3 %). Among the 23 AMR genes in our analysis, there were gyrB (100 %), tetA (93.3 %), aadA (93.3 %), sul1, sul2, sul3 (23.3 - 33.3 %), dfrA12 (16.7 %), qnrS, (6.7 %), and mcr6 (6.7 %). Two strains had the mcr6 gene but were susceptible to colistin. Our findings suggest that naturally occurring lactic acid bacteria in the Nham products are insufficient to inhibit Salmonella contamination of this pork-based food. HIGHLIGHTS Highly presence of Salmonella in fermented ground pork (Nham) All identified Salmonella isolates in the Nham have AMR genes A few Salmonella isolates carry AMR genes but are antibiotic susceptible Two Salmonella isolates contain the mcr6 gene but are susceptible to colistin

Streptococcus pneumoniae carriage in school children

Purpose. To investigate the serotype distribution, clonal structure and antimicrobial resistance of pneumococci isolated from schoolchildren.Materials and methods. During the period from 2012 to 2018 we examined 498 healthy school children aged 6 to 17 years. Oropharyngeal swab was taken from each child for culture, after that all S. pneumoniae strains were genotyped for serotype and ST-type deduction (PCR and sequencing, respectively). Antimicrobial resistance was also determined.Results. Pneumococcal culture was positive in 10.6 % of children. S. pneumoniae isolates belonged to seven serogroups and seven serotypes. Serogroup 6 and serotype 19F strains (15.1% each), and serogroup 9 strains (13.2%) were the most prevalent. S. pneumoniae33FA/37 and 3 (9.4 and 5.7%), serogroups 15 and 18 (7.6 and 5.7%), and 10A serotype (3.8%) were determined at a lower frequency. 20 detected ST-types belonged to 14 clonal complexes (CCs); CC156, CC447, and CC320 were predominant. 1.9% of isolates were penicillin-resistant; 13.2% – macrolide-, clindamycin-, and tetracycline-resistant. S. pneumoniae antibiotic resistant strains belonged to multidrug-resistant CCs 320, 315, and 156.Conclusion. S. pneumoniae prevalence in school children is not high. Pneumococcal population is characterized by serotype and clonal diversity including ‘invasive’ serotypes and genotypes. Most of strains are susceptible to antimicrobials.

The serotype distribution of Streptococcus agalactiae (GBS) carriage isolates among pregnant women having risk factors for early-onset GBS disease: a comparative study with GBS causing invasive infections during the same period in Denmark

Background We describe the serotype distribution of Streptococcus agalactiae (GBS) carriage isolates from women in labor and among GBS isolates causing invasive infections during the same period to see if the distribution of carriage serotypes reflects the GBS serotypes causing invasive diseases including early-onset disease (EOGBS). Methods Data on invasive isolates from 2019 including serotype, erythromycin and clindamycin susceptibility was retrieved from the Danish national reference laboratory, Statens Serum Institut. Carriage isolates were collected from women with risk factors for EOGBS enrolled at delivery at the maternity ward at a Danish University Hospital, first half of 2019. Results Among carriage isolates, the dominant serotype was IX (21 %) followed by serotype III (19 %). The resistance to erythromycin and clindamycin was 21 and 26 %, respectively. Among invasive GBS isolates, no case of EOGBS with serotype IX was detected but the distribution of serotypes were otherwise similar to the GBS carrier strains. The corresponding resistance to erythromycin and clindamycin was 23 and 15 %, respectively. Penicillin resistance was not detected among carriage nor invasive isolates. Conclusions The distribution of serotypes among carriage and invasive GBS reflects the assumption that EOGBS occur following transmission of GBS from mother to newborn, with the exception of serotype IX.

Invasive pneumococcal disease burden in hospitalized adults in Bogota, Colombia

Background The incidence of invasive pneumococcal disease (IPD) varies depending on a number of factors, including vaccine uptake, in both children and adults, the geographic location, and local serotype prevalence. There are limited data about the burden of Streptococcus pneumoniae (Spn), serotype distribution, and clinical characteristics of adults hospitalized due to IPD in Colombia. The objectives of this study included assessment of Spn serotype distribution, clinical characteristics, mortality, ICU admission, and the need for mechanical ventilation. Methods This was an observational, retrospective, a citywide study conducted between 2012 and 2019 in Bogotá, Colombia. We analyzed reported positive cases of IPD from 55 hospitals in a governmental pneumococcal surveillance program. Pneumococcal strains were isolated in each hospital and typified in a centralized laboratory. This is a descriptive study stratified by age and subtypes of IPD obtained through the analysis of medical records. Results A total of 310 patients with IPD were included, of whom 45.5% were female. The leading cause of IPD was pneumonia (60%, 186/310), followed by meningitis. The most frequent serotypes isolated were 19A (13.87%, 43/310) and 3 (11.94%, 37/310). The overall hospital mortality rate was 30.3% (94/310). Moreover, 52.6% (163/310 patients) were admitted to the ICU, 45.5% (141/310) required invasive mechanical ventilation and 5.1% (16/310) non-invasive mechanical ventilation. Conclusion Pneumococcal pneumonia is the most prevalent cause of IPD, with serotypes 19A and 3 being the leading cause of IPD in Colombian adults. Mortality due to IPD in adults continues to be very high.

Serotyping and Antibiotic Susceptibility of Invasive Streptococcus agalactiae in Egyptian Patients with or without Diabetes Mellitus

Streptococcus agalactiae serotype distribution and its antibiotic susceptibility affect disease prevention strategies, but the serotype distribution varies among patient groups. The objectives of this study were to establish the group B Streptococcus (GBS) serotype distribution in patients from Egypt and to assess antibiotic sensitivity of invasive GBS isolates. A total of 490 patients participated in this multicenter study; 160 had urinary tract infection, 115 complained of diabetic foot ulcers, 125 men had genital tract infections, and 30 women females had genital tract infections. Others had bronchopneumonia, otitis media, synovitis, or meningitis. Serotyping of the isolated GBS was performed at the CDC in the United States. Antibiotic sensitivity patterns were determined using the disk diffusion method. In men, the most common serotypes were II, III, and V, whereas types Ia, II, III, and V were isolated from women. Macrolides (erythromycin) resistance occurred in 4.1% of the isolates; 10.2% were resistant to both clindamycin and inducible resistance of macrolides, lincomycin, and streptogramin; 17.3% were resistant to quinolones; and 95.9% were resistant to tetracyclines. GBS primarily infected the urinary tract, skin, soft tissue, and genital tract in both genders. Isolates were sensitive to beta-lactam drugs, vancomycin, and linezolid; 14.0% were resistant to macrolides with or without clindamycin. Only 6.0% of the strains were sensitive to tetracyclines. Although GBS causes invasive infections in Egyptian adults, it rarely causes neonatal meningitis or sepsis. Future studies should determine whether GBS isolates are transmitted sexually, by performing a follow-up study of the partner of the infected patient.

Burden of invasive group B Streptococcus disease in non-pregnant adults: A systematic review and meta-analysis

Background Streptococcus agalactiae or group B Streptococcus (GBS) has emerged as an important cause of invasive disease in adults, particularly among the elderly and those with underlying comorbidities. Traditionally, it was recognised as an opportunistic pathogen colonising and causing disease in pregnant women, neonates, and young infants. Reasons for the upsurge of invasive GBS (iGBS) among the elderly remain unclear, although it has been related to risk factors such as underlying chronic diseases, immunosenescence, impaired inflammatory response, and spread of virulent clones. Antibiotics are successfully as treatment or prophylaxis against iGBS. Several candidate vaccines against iGBS are under development. Objectives To conduct a systematic review of the current literature on invasive GBS in order to determine disease incidence and case fatality ratio (CFR) among non-pregnant adults. Additionally, information on risk factors, clinical presentation, serotype distribution, and antimicrobial resistance was also retrieved. Methods Between January and June 2020, electronic searches were conducted in relevant databases: MEDLINE, EMBASE, Global Health, and SCOPUS. Studies were included in the systematic review if they met the inclusion/exclusion criteria. The authors assessed the selected studies for relevance, risk of bias, outcome measures, and heterogeneity. Meta-analyses on incidence and CFR were conducted after evaluating the quality of methods for assessment of exposure and outcomes. Results Pooled estimates of iGBS incidence in non-pregnant adults 15 years and older were 2.86 cases per 100.000 population (95% CI, 1.68–4.34). Incidence rates in older adults were substantially higher, 9.13 (95%CI, 3.53–17.22) and 19.40 (95%CI, 16.26–22.81) per 100.000 population ≥50 and ≥ 65 years old, respectively. Incidence rates ranged from 0.40 (95% CI, 0.30–0.60) in Africa to 5.90 cases per 100.000 population (95% CI, 4.30–7.70) in North America. The overall CFR was and 9.98% (95% CI, 8.47–11.58). CFR was highest in Africa at 22.09% (95% CI, 12.31–33.57). Serotype V was the most prevalent serotype globally and in North America accounting for 43.48% (n = 12926) and 46,72% (n = 12184) of cases, respectively. Serotype Ia was the second and serotype III was more prevalent in Europe (25.0%) and Asia (29.5%). Comorbidities were frequent among non-pregnant adult iGBS cases. Antimicrobial resistance against different antibiotics (i.e., penicillin, erythromycin) is increasing over time. Conclusions This systematic review revealed that iGBS in non-pregnant adults has risen in the last few years and has become a serious public health threat especially in older adults with underlying conditions. Given the current serotype distribution, vaccines including serotypes predominant among non-pregnant adults (i.e., serotypes V, Ia, II, and III) in their formulation are needed to provide breadth of protection. Continued surveillance monitoring potential changes in serotype distribution and antimicrobial resistance patterns are warranted to inform public health interventions.

Serotype Distribution of Streptococcus pneumoniae Carriage ‎in Six-Month-Old Infants: A Cross-sectional Study During 2017-18, Tehran, ‎Iran

Background: Streptococcus pneumoniae is recognized as one of the main pathogens inducing several invasive and non-invasive infections in children. Objective: The present study aimed to evaluate the serotype distribution of S. pneumoniae in six–month–old carriers. Methods: This study encompassed 600 six-month-old healthy infants whose pharyngeal swap samples were collected and then cultured to isolate S. pneumoniae. Twenty- five different serotypes were defined on positive culture samples by multiplex PCR. Results: In this study, 13 cases (2.2%) were positive S. pneumonia. The most common isolated serotypes of S. pneumoniae were serotypes 23F (n = 6, 1%) and 3 (n = 3, 0.5%), respectively. Notably, the most frequent serotype in formula-fed infants (n = 300) was Serotype 23F (n = 5, 1.7%); however, Serotype 3 (n = 3, 1%) was the most frequent one in breastfed participants (n = 300). According to the findings, the overall coverage of PCV10, PCV13, and PPSV23 on the S. pneumoniae serotypes at the age of six months was 50%, 73%, and 85%, respectively. Conclusions: At this age, the type of feeding could not significantly affect the frequency rate of S. pneumoniae colonization, while the serotype distributions in the two breastfed and formula-fed groups were different.

Nasopharyngeal Carriage in Children After the Introduction of Generalized Infant Pneumococcal Conjugate Vaccine Immunization in Germany

Epidemiological data on nasopharyngeal (NP) bacterial carriage in children in Germany are scarce. We prospectively characterized NP colonization to evaluate the impact of pneumococcal immunization. We longitudinally collected NP swabs from 2-month-old infants (visit 1; V1) at eight representative pediatric offices 10/2008-06/2009. The second swabs were taken at age 9–12 months (V2); the third swab was taken 3–6 months after the booster vaccination at age 17–19 months (V3), and the fourth swab (V4) at age 59–61 months. Samples were broth enriched, cultured for bacteria, and isolates were serotyped. Demographic risk factors for colonization were evaluated. Among 242 vaccinees, bacterial NP carriage increased with age [from 27.2% (V1) to 70.1% (V4)]; leading isolates were S. pneumoniae, H. influenzae, M. catarrhalis, and S. pyogenes. Overall pneumococcal carriage increased [14.7% (V1), 31.5% (V2), 34.8% (V3), 42.2% (V4)], being even greater among day-care attendees. Serotype distribution changed during the study period, with vaccine serotypes declining. At visit 4, 10-valent pneumococcal conjugate vaccine (PCV10) serotypes were no longer among the NP flora, while some serotypes unique to 13-valent pneumococcal conjugate vaccine (PCV13; 3 and 19A) were found. In Germany, universal infant PCV immunization was associated with an almost complete eradication of PCV-serotypes and concomitant increase of non-PCV-serotypes, mainly 11A, 22F, and 23A.