, or group B streptococcus (GBS), is a leading neonatal pathogen that causes sepsis, meningitis and pneumonia. Globally, strategies have been implemented to address vertical transmission, and in Western Australia (WA), culture-based screening at 35–37 weeks’ gestation is part of routine care and guides antibiotic administration. Previous Australian studies have focused on other regions or included low sample-size representatives; we aimed to describe antenatal GBS colonization in WA.
Methodology. A cohort of 814 pregnant women attending antenatal clinics (2015–2017) self-collected vaginal and rectal swabs at ≤22 weeks (n=814) and ≥33 weeks’ (n=567) gestation. These were assessed for GBS presence using culture and PCR, and serotyping was conducted using molecular methods. Lifestyle questionnaires and medical data were collected.
Results. We observed an overall GBS colonization rate of 24%, with 10.6 % of positive participants transiently colonized. Ethnicity (Aboriginal, Torres Strait Islander and African), maternal age ≥25 years, vitamin use, frequent sexual intercourse (≥5 times/week) and use of sex toys were associated with GBS colonization. The dominant serotypes identified were Ia (27.9%), III (20.9%), II (16.3%), V (15.8%), Ib (8.4%), VI (5.1%), IV (2.8%), NT (1.9), VIII (0.5%) and IX (0.5%) at visit one, with V (18.9%) preceding serotype II (18.2%) at visit two. Serotype VII was not detected.
Conclusion. This is the first cohort study to assess GBS colonization in Western Australian pregnant women and will be highly beneficial for guiding clinical practice and future therapeutic options, in particular, the selection of suitable vaccine candidates.
(MRSA) can be classified into hospital-acquired MRSA (HA-MRSA) and community-associated MRSA (CA-MRSA), based on the associated epidemiological risk factors and their SCCmec types. We therefore studied the diversity and distribution of SCCmec elements among MRSA isolates in our region and also evaluated SCCmec typing as a tool for the classification of MRSA.
Methodology. Two hundred isolates of MRSA obtained from various clinical specimens were included. The clinical and demographic details of the patients and the epidemiological risk factors for MRSA acquisition were documented. Multiplex PCR was optimized for all the major SCCmec types (I to V). Subtyping of SCCmec type IV (IVb, IVc, IVd, IVh) was carried out by simplex PCR.
Results. Based on epidemiological criteria, CA-MRSA constituted 57 % (114/200) of the the test isolates and HA-MRSA made up 43 % (86/200). The predominant SCCmec type found in our study was type III (62%), followed by type V (52.5%) and type I (47.5%), while type II was carried by a single isolate. Of the 200 isolates, 118 carried multiple SCCmec types and 3 were non-typable.
Conclusion. The existence of multiple SCCmec types in individual MRSA isolates resulted in our inability to categorize many of these isolates as either CA-MRSA or HA-MRSA as defined by the SCCmec type criterion.
Limitation. The major limitation of the study was that the SCC mec element of MRSA isolates exhibiting multiple types was not sequenced and hence this finding could not be confirmed.
Purpose. Antimicrobial resistance (AMR) is of increasing global concern, threatening to undermine recent progress in reducing child and neonatal mortality. Repurposing older antimicrobials is a prominent strategy to combat multidrug-resistant sepsis. A potential agent is fosfomycin, however, there is scarce data regarding its in vitro activity and pharmacokinetics in the paediatric population.
Methodology. We analysed a contemporary, systematically collected archive of community-acquired (CA) and hospital-acquired (HA) paediatric Gram-negative bacteraemia isolates for their susceptibility to fosfomcyin. MICs were determined using agar serial dilution methods and validated by disk diffusion testing where breakpoints are available. Disk diffusion antimicrobial susceptibility testing was also conducted for current empirical therapies (ampicillin, gentamicin, ceftriaxone) and amikacin (proposed in the literature as a new combination empirical therapeutic option).
Results. Fosfomycin was highly active against invasive Gram-negative isolates, including 90 % (202/224) of
and 96 % (22/23) of
spp. Fosfomycin showed high sensitivity against both CA isolates (94 %, 142/151) and HA isolates (81 %, 78/96; P =0.0015). CA isolates were significantly more likely to be susceptible to fosfomycin than the current first-line empirical therapy (96 % vs 59 %, P <0.0001). Extended spectrum β-lactamases (ESBL) production was detected in 34 % (85/247) of isolates with no significant difference in fosfomycin susceptibility between ESBL-positive or -negative isolates [73/85 (86 %) vs 147/162 (91 %) respectively, P =0.245]. All isolates were susceptible to a fosfomycin-amikacin combination.
Conclusion. Gram-negative paediatric bacteraemia isolates are highly susceptible to fosfomycin, which could be combined with aminoglycosides as a new, carbapenem-sparing regimen to achieve excellent coverage to treat antimicrobial-resistant neonatal and paediatric sepsis.
Purpose. Invasive early-onset group B
infection (EOGBS) is an important cause of severe neonatal complications but study on comprehensive GBS screening is lacking in China. This study aims to investigate the outcome of a regional anterpartum screening program for EOGBS prevention and to estimate the pros and cons of a new GBS screening strategy employed.
Methods. We performed an optimized hospital strategy for GBS screening, which targeted expectant mothers (including those with preterm births) from January 2016 to December 2016 in a population-based cohort. Three common screening strategies were simulated to estimate the availability of the hospital strategy used in this study.
Results. Altogether, 9770 eligible women were tested and the rate of GBS carriage was 2.7 % (266/9770). In total, 198 of the 266 maternal GBS carriers accepted intrapartum antibiotic prophylaxis (IAP) treatment. Among the 9860 neonates of 9770 mothers, four cases of EOGBS infection were identified and one case was missed (EOGBS incidence with screening and IAP: 0.5/1000). Risk factors for maternal GBS colonization included preterm birth (between 35 and 37 weeks) [odds ratio (OR)=1.7 (95 % confidence interval: 1.22–2.33)], region of origin, resident areas, maternal age (older than 34 years) [OR=1.5 (1.06–2.09)], prelabour rupture of membranes [OR=1.8 (1.34–2.35)], gestational diabetes mellitus [OR=1.6 (1.14–2.28)] and maternal mild anemia (Hb: 90–110 g dl−1) [OR=1.5 (1.16–2.06)]. This new screening strategy resulted in less antibiotic exposure and least number of cases missed.
Conclusions. Our findings illustrate that this perinatal screening (including preterm births) for prevention of EOGBS infection can be implemented in the Inner Mongolian area.
Purpose. Syphilis, caused by
Treponema pallidum subspecies pallidum
, is considered as an old disease affecting humans; traces of such infections, including congenital syphilis, are potentially identifiable in archaeological samples. The aim of this research was to perform macroscopic and molecular investigations of
on six infant remains, buried between 1837 and 1867, from the cemetery of ‘Les Crottes’ in Marseille city (southeastern France).
Methodology. Pathological analysis of bones from individuals, aged from the twenty-ninth week of amenorrhea to 4–9 months, was performed. Samples served also as a source of ancient DNA (aDNA) for PCR-based molecular investigations targeting
DNA; all samples were also tested for
and Plasmodium falciparum DNA. Sequences characterized were cloned and sequenced, and compared to those available in databases.
Results/Key findings. All samples tested displayed widespread osteoporotic lesions across the skeleton possibly related to some metabolic or infectious disorders. Subsequent molecular analysis revealed that one individual, SP332 (unborn, 29 amenorrhea weeks, inhumation date 1864–1866), exhibited positive signals for the five
amplification systems tested; sequence analysis provided strong evidence for the effective detection of
T. pallidum subspecies pallidum
Conclusions. Individual SP332 is the first PCR-confirmed palaeopathological case of syphilis identified in France, and the youngest specimen ever to be diagnosed with certainty for congenital syphilis. Future research aimed at better characterizing this 150-year-old treponeme genome and exploring new archaelogical cases of syphilis in the very young should contribute to a better comprehension of the disease's history.
Tuberculosis (TB) meningitis is extremely difficult to diagnose due to its pauci-bacillary disease nature and new techniques are needed. Improved test sensitivity would allow for greater clinician confidence in diagnostic testing and has the potential to improve patient outcomes. Traditional microbiologic and molecular tests for TB meningitis focus on detection of TB bacilli and are inadequate. Smear microscopy is rapid but only ~10–15 % sensitive. Culture has 50–60 % sensitivity but is slow. Xpert MTB/Rif Ultra is a rapid, automated PCR-based assay with ~70 % sensitivity versus clinical case definition. Thus, even the best current testing may miss up to 30 % of cases. Clinicians are often left to treat empirically with prolonged regimens with significant side effects or risk a missed case that would result in death. Rather than relying strictly on microbiologic or molecular testing to diagnose TB meningitis, we propose that testing of CSF for biomarkers of host response may have an adjunctive role to play in improving the diagnosis of TB meningitis.
is an opportunistic pathogen and a leading cause of morbidity and premature mortality in patients with medical device-related infections, which is a concern in hospitalized patients. Developing a strategy to raise opsonic antibodies against polysaccharide intracellular adhesin (PIA) could be promising for the elimination of colonizing and biofilm-forming
S. epidermidis. Following the purification of truncated rSesC protein and PIA, for the first time, PIA was conjugated to rSesC as a carrier to increase the immunogenicity of PIA and its efficacy in mice was evaluated. The structure of the conjugate was analysed using the Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance spectroscopy (H1- NMR) methods. Afterwards, the immune response was evaluated by measuring the total IgG, IgG2a and IgG2b titres.
Results. The immunization of mice with the PIA–rSesC conjugate raised the levels of opsonic antibodies, and the vaccinated mice were protected when challenged intravenously by wild-type
S. epidermidis strain 1457. Further studies indicated that the conjugated vaccine was able to eliminate
biofilm formation in in vitro or in vivo assays.
Conclusion. This study confirms the proposal that the immunization of mice with PIA-rSesC conjugate vaccine could protect against
Antibiotic-resistant genes (ARGs) are regarded as emerging environmental pollutants and pose a serious health risk to the human population. Integrons are genetic elements that are involved in the spread of ARGs amongst bacterial species. They also act as reservoirs of these resistance traits, further contributing to the development of multi-drug resistance in several water-borne pathogens. Due to inter- and intra-species transfer, integrons are now commonly reported in important water-borne pathogens such as
and other opportunistic pathogens. These pathogens exhibit immense diversity in their resistance gene cassettes. The evolution of multiple novel and complex gene cassettes in integrons further suggests the selection and horizontal transfer of ARGs in multi-drug resistant bacteria. Thus, the detection and characterization of these integrons in water-borne pathogens, especially in epidemic and pandemic strains, is of the utmost importance. It will provide a framework in which health authorities can conduct improved surveillance of antibiotic resistance in our natural water bodies. Such a study will also be helpful in developing better strategies for the containment and cure of infections caused by these bacteria.
Purpose. Serological analysis is an essential tool for the diagnosis of pertussis or whooping cough, disease surveillance and the evaluation of vaccine effectiveness against
. Accurate measurement of anti-pertussis toxin (anti-PT) IgG antibody levels in sera is essential. These measurements are usually performed using immunological methods such as ELISA and multiplex immunoassays. However, there are a large number of different assay systems available, and therefore standardization and harmonization between the methods are needed to obtain comparable data.
Methodology. In collaboration with ECDC, the EUPert-LabNet network has organized three External Quality Assessment (EQA) schemes (2010, 2012 and 2016), which initially identified the diverse range of techniques and reagents being used throughout Europe. This manuscript discusses the findings of each of the EQA rounds and their impact on the participating laboratories.
Results. The studies have shown an increasing number of laboratories (from 65% to 92%) using only the recommended coating antigen, purified PT, in immunoassays, as this allows exact quantification of serum anti-PT IgG and since PT is only produced by
this prevents cross-reactivity with other species. There has also been an increase in the numbers of laboratories (from 59% to 92%), including a WHO reference serum in their assays, which allows anti-PT IgG concentrations to be measured in International Units, thus enabling the comparison of results from different methods and laboratories. In addition, manufacturers have also considered these recommendations when they produce commercial ELISA kits.
Conclusion. The three EQA rounds have resulted in greater harmonization in methods among different laboratories, showing a significant improvement of the ELISA methods used for serodiagnosis of pertussis.
Penicillium is the most common mould isolated in housing. Penicillium chrysogenum is the only species tested by prick test or serology for allergic patients. The American Institute of Medicine has accepted Penicillium as an aetiological agent of rhinitis in children and adults and as an asthma agent in children. However, few studies have identified Penicillium in housing to the species level (354 species). Phenotypic identification is difficult. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) should be an alternative. The aim of this study was (1) to identify the Penicillium species present in dwellings in Eastern France and (2) to evaluate the reliability of MALDI-TOF MS for identification, by comparing it to DNA sequencing and phenotypic identification.
Methodology. Identification to the species level was performed by MALDI-TOF MS on 275 strains isolated from 48 dwellings. These results were compared to beta-tubulin gene sequencing and to the phenotypic aspects.
Results. Thanks to MALDI-TOF, 235/275 strains could be identified (85.5 %). Fourteen species were identified among 23 Penicillium species included in the Filamentous Fungi Library 1.0 (Bruker Daltonics). However, 72.2 % of the strains belonged to five main taxa: P. chrysogenum (27.3 %), Penicillium glabrum (22.9 %), Penicillium
commune (11.3 %), Penicillium brevicompactum (6.5 %) and Penicillium expansum (4.2 %).
Conclusion. Complete coherence between MALDI-TOF MS and sequence-based identification was found for P. chrysogenum, P. expansum, P. glabrum, Penicillium italicum and Penicillium corylophilum. The main drawback was observed for Penicillium crustosum, which included 21 strains (7.6 %) that could not be identified using MALDI-TOF MS.