Pharyngeal carriage rates of Neisseria meningitidis in health care professionals at a tertiary university pediatric hospital.

Pharyngeal carriage is the reservoir for Neisseria meningitidis in the population and the first step in disease transmission. Especially in young infants and adolescents, N. meningitidis can cause serious invasive infection with high fatality rates and high rates of long-term sequelae among survivors. The aim of this study was to determine N. meningitidis colonization rates in asymptomatic health care professionals at a tertiary university pediatric hospital and to identify risk factors for carriage. This cross-sectional meningococcal carriage survey was conducted between April and October 2018 at the Medical University of Vienna. Individuals working as nurses, pediatricians, or medical students were enrolled. Oropharyngeal swabs were directly plated onto selective agar plates and conventional culture was used for bacterial identification. Meningococcal isolates were further characterized using whole-genome sequencing. A total of 437 oropharyngeal specimens were collected. Overall, meningococcal carriage prevalence was 1.14% (5/437), with 0.7% (3/437) for capsular genotype B, and 0.5% (2/437) for capsular genotype W. Mean age of carriers was significantly lower than of non-carriers (24.2 vs. 35.8; p = 0.004). The highest carriage rate of 4.4% (4/91) was found in the age group 18-25. Carriage was negatively associated with age and timespan working in pediatrics. This is the first study evaluating the prevalence of Neisseria meningitidis carriage in health care professionals working in Pediatrics and Adolescent Medicine. Carriage was in general lower than expected for all age groups, implicating a low risk of meningococcal transmission via this population.

Genetic Meningococcal Antigen Typing System (gMATS): A genotyping tool that predicts 4CMenB strain coverage worldwide.

BACKGROUND: The Meningococcal Antigen Typing System (MATS) was developed to identify meningococcus group B strains with a high likelihood of being covered by the 4CMenB vaccine, but is limited by the requirement for viable isolates from culture-confirmed cases. We examined if antigen genotyping could complement MATS in predicting strain coverage by the 4CMenB vaccine. METHODS: From a panel of 3912 MATS-typed invasive meningococcal disease isolates collected in England and Wales in 2007-2008, 2014-2015 and 2015-2016, and in 16 other countries in 2000-2015, 3481 isolates were also characterized by antigen genotyping. Individual associations between antigen genotypes and MATS coverage for each 4CMenB component were used to define a genetic MATS (gMATS). gMATS estimates were compared with England and Wales human complement serum bactericidal assay (hSBA) data and vaccine effectiveness (VE) data from England. RESULTS: Overall, 81% of the strain panel had genetically predictable MATS coverage, with 92% accuracy and highly concordant results across national panels (Lin's accuracy coefficient, 0.98; root-mean-square deviation, 6%). England and Wales strain coverage estimates were 72-73% by genotyping (66-73% by MATS), underestimating hSBA values after four vaccine doses (88%) and VE after two doses (83%). The gMATS predicted strain coverage in other countries was 58-88%. CONCLUSIONS: gMATS can replace MATS in predicting 4CMenB strain coverage in four out of five cases, without requiring a cultivable isolate, and is open to further improvement. Both methods underestimated VE in England. Strain coverage predictions in other countries matched or exceeded England and Wales estimates.

Petting zoos as sources of Shiga toxin-producing Escherichia coli (STEC) infections.

Despite their general low incidence, Shiga toxin-producing Escherichia (E.) coli (STEC) infections are considered an important public health issue due to the severity of illness that can develop, particularly in young children. We report on two Austrian petting zoos, one in Tyrol (2015) and one in Vorarlberg (2016), which were identified as highly likely infection sources of STEC infections. The petting zoo related cases involved a case of hemolytic uremic syndrome (HUS) due to STEC O157:HNM in 2015 and an outbreak of STEC O157:H7 infections affecting five young children and two adults in 2016. The HUS case accounted for 2.8% of the 36 STEC O157:HNM/H7 infections notified in Austria in 2015 (5,9% of 17 HUS cases). The seven cases described for 2016 accounted for 4.0% of the 177 human STEC infections documented for Austria in 2016, and for 19.4% of the 36 STEC O157:HNM/H7 infections notified that year. The evaluation of the STEC infections described here clearly underlines the potential of sequence-based typing methods to offer suitable resolutions for public health applications. Furthermore, we give a state-of-the-art mini-review on the risks of petting zoos concerning exposure to the zoonotic hazard STEC and on proper measures of risk-prevention.

Characterization of Streptococcus pneumoniae isolates from Austrian companion animals and horses.

BACKGROUND: The aim of the present study was to investigate the genetic relatedness and the antimicrobial resistance profiles of a collection of Austrian Streptococcus pneumoniae isolates from companion animals and horses. A total of 12 non-repetitive isolates presumptively identified as S. pneumoniae were obtained during routinely diagnostic activities between March 2009 and January 2017. RESULTS: Isolates were confirmed as S. pneumoniae by bile solubility and optochin susceptibility testing, matrix-assisted laser desorption-ionization-time of flight (MALDI-TOF) mass spectrometry and sequence analysis of a part recA and the 16S rRNA genes. Isolates were further characterized by pneumolysin polymerase chain reaction (PCR) and genotyped by multilocus sequence typing (MLST). Antimicrobial susceptibility testing was performed and resistance genes were detected by specific PCR assays. All isolates were serotyped. Four sequence types (ST) (ST36, ST3546, ST6934 and ST6937) and four serotypes (3, 19A, 19F and 23F) were detected. Two isolates from twelve displayed a multidrug-resistance pheno- and genotype. CONCLUSIONS: This study represents the first comprehensive investigation on characteristics of S. pneumoniae isolates recovered from Austrian companion animals and horses. The obtained results indicate that common human sero- (23F) and sequence type (ST36) implicated in causing invasive pneumococcal disease (IPD) may circulate in dogs. Isolates obtained from other examined animals seem to be host-adapted.

Salmonellosis in Austria: situation and trends.

Non-typhoidal Salmonella spp. are a major cause of human gastroenteritis in many parts of the world. Most of these infections are zoonotic and are transmitted from healthy carrier animals to humans through contaminated food. In Austria we are facing an ongoing salmonellosis epidemic that started in 1989. The main cause of the epidemic is a massive increase of infections due to S. enterica subsp. enterica serovar Enteritidis (S. Enteritidis), a serotype prevalent in poultry, particularly in eggs. The introduction of vaccination of laying hens and broilers, together with intensified outbreak investigation efforts, has led to a remarkable decrease of human salmonella isolates. Since 2002 the number of isolates received by the National Reference Center for Salmonella (NRCS) has been reduced by more than 50%. Overall rates of antibiotic resistance in salmonella have remained stable over the past years. In Austria, high levels of resistance to ciprofloxacin and third-generation cephalosporins (cefotaxime) are still extremely rare.

Multiple-locus variable-number tandem repeat analysis for subtyping of Salmonella enterica subsp. enterica serovar Enteritidis.

Salmonella enterica subsp. enterica serovar Enteritidis is a major food-borne pathogen that caused most of Salmonella infections worldwide. S. Enteritidis phage type 4 (PT4) especially presents a real challenge for the classical typing methods. We developed a simple multiple-locus variable-number tandem repeat analysis (MLVA) assay based on three hypervariable variable-number tandem repeat (VNTR) loci for subtyping of Salmonella Enteritidis. Testing an arbitrary chosen strain collection of 110 S. Enteritidis isolates, comprising PTs 4, 8, and 21, the MLVA assay yielded a higher discriminatory power, corresponding to a Simpson's index of diversity (ID) of 0.91, when compared to pulsed-field gel electrophoresis (PFGE) which had a Simpson's ID of 0.41. To simplify interpretation of results, we developed a VNTR allele code based on the repeat unit number. This code can easily be exchanged. In conclusion, MLVA is a promising new tool to investigate outbreaks of S. Enteritidis and constitutes a useful addition to the current phage typing scheme.