Experiences and Lessons from a Multicountry NIDIAG Study on Persistent Digestive Disorders in the Tropics.

<p>Experiences and Lessons from a Multicountry NIDIAG Study on Persistent Digestive Disorders in the Tropics</p

Short communication : barrier characteristics of 3 external teat sealants to prevent bacterial penetration under in vitro conditions using rubber calf -feeding nipples

The main objective of this study was to evaluate the barrier characteristics of 3 external teat sealants for dry cows in preventing bacterial penetration by 3 common major mastitis pathogens (Escherichia coli, Staphylococcus aureus, and Streptococcus uberis) via a novel in vitro simulation model using rubber calf-feeding nipples. All feeding nipples were filled with a sterile cotton plug soaked in sterile broth heart infusion medium and were treated as follows: rubber teats 1 and 5 were sealed with Ubera Dry (Inovet, Arendonk, Belgium); rubber teats 2 and 6 were sealed with T-Hexx Dry (Huvepharma Livestock, St. Louis, MO); rubber teats 3 and 7 were sealed with Uddergold Dry (Ecolab Food and Beverage Division, St. Paul, MN); and rubber teats 4 and 8 remained unsealed and served as positive and negative controls, respectively. After the dips had dried, rubber teats 1 to 4 were immersed in a suspension of E. coli (experiment 1), Staph. aureus (experiment 2), or Strep. uberis (experiment 3; ≥1.5 × 108 cfu/mL) for 24 h, whereas rubber teats 5 to 8 were not exposed to the bacterial suspensions. All external teat sealants adhered well to the rubber teats. All cotton plugs collected from the teats that were not exposed to E. coli, Staph. aureus, or Strep. uberis (rubber teats 5 to 8) remained culture-negative, except for 1 (due to contamination). Of the rubber teats that were exposed to the major mastitis pathogens, all cotton plugs collected from the teats dipped with Ubera Dry and T-Hexx Dry remained culture-negative for the mastitis pathogen they were exposed to. The cotton plugs of the rubber teats that were sealed with Uddergold Dry and exposed to E. coli and Strep. uberis showed positive cultures for the respective bacteria, as demonstrated using strain-typing. The cotton plugs collected from the rubber teats that were not sealed with an external teat sealant and that served as positive controls became culture-positive for the mastitis pathogens they were exposed to. We conclude that Ubera Dry showed comparable and superior barrier performance against penetration of E. coli, Staph. aureus, and Strep. uberis compared with T-Hexx Dry and Uddergold Dry, respectively, under in vitro conditions using a novel in vitro simulation model. Although one should be aware that the method has not yet been validated to predict risk of intramammary infections, the proposed technique can be a meaningful starting point to evaluate and compare the barrier characteristics of external teat sealants in preventing bacterial penetration. A large-scale clinical trial is needed before any definite conclusions can be drawn as to the adherence, duration of adherence, barrier performance, and efficacy in protection against intramammary infections of the 3 external teat sealants under field conditions

Insulin resistance and CGM-derived parameters in people with type 1 diabetes : are they associated?

Abstract: Background: Insulin resistance (IR) is increasingly more prevalent in people with type 1 diabetes (T1D). We investigated whether IR is associated with continuous glucose monitor (CGM)-derived parameters (glucometrics) such as time in range (TIR), time above range (TAR), time below range (TBR) and glycaemic variability (CV). Methods: This is a retrospective analysis of two databases: IR was quantified according to the estimated glucose disposal rate (eGDR) (NCT04664036) and by performing a hyperinsulinaemic-euglycaemic clamp (HEC) (NCT04623320). All glucometrics were calculated over 28 days. Results: A total of 287 subjects were included. Mean age was 46 \ub1 17 years, 55% were male, TIR was 57 \ub1 14% and eGDR was 7.6 (5.6 - 9.3) mg/kg min. The tertile of people with the lowest eGDR (highest level of IR) had a higher TAR compared to the tertile with the highest eGDR (39 \ub1 15% versus 33 \ub1 14, p = 0.043). Using logistic regression, a higher eGDR was associated with a higher chance to fall in a higher TIR- (OR 1.251, p < 0.001), a lower TAR- (OR 1.281, p < 0.001) and a higher TBR-tertile (OR 0.893, p = 0.039), adjusted for age, sex, diabetes duration, smoking status and alcohol intake. In the 48 people undergoing a HEC, no significant association between glucometrics and the HEC-determined glucose disposal rate (M-value) was observed. Conclusion: In people with T1D, an association between IR, measured by eGDR, and worse CGM profiles was observed

Bovine-associated non-aureus staphylococci suppress Staphylococcus aureus biofilm dispersal in vitro yet not through agr regulation

Biofilm formation is a significant virulence factor in Staphylococcus (S.) aureus strains causing subclinical mastitis in dairy cows. A role of environmental signals and communication systems in biofilm development, such as the agr system in S. aureus, is suggested. In the context of multispecies biofilm communities, the presence of non-aureus staphylococci (NAS) might influence S. aureus colonization of the bovine mammary gland, yet, such interspecies interactions have been poorly studied. We determined whether 34 S. chromogenes, 11 S. epidermidis, and 14 S. simulans isolates originating from bovine milk samples and teat apices (TA) were able to affect biofilm formation and dispersion of S. aureus, and if so, how isolate traits such as the capacity to regulate the S. aureus agr quorum sensing system are determinants in this process. The capacity of an agr-positive S. aureus strain to form biofilm was increased more in the presence of S. chromogenes than in the presence of S. simulans and S. epidermidis isolates and in the presence of NAS isolates that do not harbor biofilm related genes. On the other hand, biofilm dispersion of this particular S. aureus strain was suppressed by NAS as a group, an effect that was more pronounced by isolates from TA. Furthermore, the observed effects on biofilm formation and dispersion of the agr-positive S. aureus strain as well as of an agr-negative S. aureus strain did not depend on the capacity of NAS to repress the agr system

Metabolites of bovine-associated non-aureus staphylococci influence expression of Staphylococcus aureus agr-related genes in vitro

Communications via quorum sensing (QS) between non-aureus staphylococci (NAS) and Staphylococcus (S.) aureus in the bovine mammary gland remains largely unexplored. We determined whether 34 S. chromogenes, 11 S. epidermidis, and 14 S. simulans isolates originating from bovine milk samples and teat apices were able to regulate the QS of S. aureus, and if so, how in vitro growth inhibition of S. aureus by NAS, or NAS metabolites, or NAS cells themselves play a role in this process. In co-culture with S. aureus we observed that these 3 NAS species in general downregulated the expression of rnaIII, the effector molecule of the QS system, but this effect was more pronounced in S. chromogenes and S. simulans isolates than in S. epidermidis isolates. In vitro growth inhibition of S. aureus by NAS resulted in a small underestimation of the downregulating effect of NAS on rnaIII expression of S. aureus. Additionally, the culture supernatant of these NAS isolates and supernatant treated with proteinase K expressed greater regulatory activity over S. aureus virulence genes rnaIII, hla, and spa than washed NAS cells suspended in sterile water. These microbial interactions may influence S. aureus virulence and pathogenesis within the host. Isolation and identification of NAS metabolites affecting the QS system of S. aureus might help to develop alternative strategies for treatment and control of S. aureus mastitis

Genetic diversity and iron metabolism of Staphylococcus hominis isolates originating from bovine quarter milk, rectal feces, and teat apices

Staphylococcus hominis, a member of the non-aureus staphylococci (NAS) group, is part of the human and animal microbiota. Although it has been isolated from multiple bovine-associated habitats, its relevance as a cause of bovine mastitis is currently not well described. To successfully colonize and proliferate in the bovine mammary gland, a bacterial species must be able to acquire iron from host iron-binding proteins. The aims of this study were (1) to assess the genetic diversity of S. hominis isolated from bovine quarter milk, rectal feces, and teat apices, and (2) to investigate the capacity of bovine S. hominis isolates belonging to these different habitats to utilize ferritin and lactoferrin as iron sources. To expand on an available collection of bovine S. hominis isolates (2 from quarter milk, 8 from rectal feces, and 19 from teat apices) from one commercial dairy herd, a subsequent single cross-sectional quarter milk sampling (n = 360) was performed on all lactating cows (n = 90) of the same herd. In total, 514 NAS isolates were recovered and identified by MALDI-TOF mass spectrometry; the 6 most prevalent NAS species were S. cohnii (33.9%), S. sciuri (16.7%), S. haemolyticus (16.3%), S. xylosus (9.6%), S. equorum (9.4%), and S. hominis (3.5%). A random amplified polymorphic DNA (RAPD) analysis was performed on 46 S. hominis isolates (19 from quarter milk, 8 from rectal feces, and 19 from teat apices). Eighteen distinct RAPD fingerprint groups were distinguished although we were unable to detect the presence of the same RAPD type in all 3 habitats. One S. hominis isolate of a distinct RAPD type unique to a specific habitat (8 from quarter milk, 3 from rectal feces, and 4 from teat apices) along with the quality control strain Staphylococcus aureus ATCC 25923 and 2 well-studied Staphylococcus chromogenes isolates ("IM" and "TA") were included in the phenotypical iron test. All isolates were grown in 4 types of media: iron-rich tryptic soy broth, iron-rich tryptic soy broth deferrated by 2,2'-bipyridyl, and deferrated tryptic soy broth supplemented with human recombinant lactoferrin or equine spleen-derived ferritin. The growth of the different strains was modified by the medium in which they were grown. Staphylococcus chromogenes TA showed significantly lower growth under iron-deprived conditions, and adding an iron supplement (lactoferrin or ferritin) resulted in no improvement in growth; in contrast, growth of S. chromogenes IM was significantly recovered with iron supplementation. Staphylococcus hominis strains from all 3 habitats were able to significantly utilize ferritin but not lactoferrin as an iron source to reverse the growth inhibition, in varying degrees, caused by the chelating agent 2,2'-bipyridyl

Diagnosis of neglected tropical diseases among patients with persistent digestive disorders (diarrhoea and/or abdominal pain ≥14 days) : Pierrea multi-country, prospective, non-experimental case-control study

Diarrhoea still accounts for considerable mortality and morbidity worldwide. The highest burden is concentrated in tropical areas where populations lack access to clean water, adequate sanitation and hygiene. In contrast to acute diarrhoea (>14 days), the spectrum of pathogens that may give rise to persistent diarrhoea (≥14 days) and persistent abdominal pain is poorly understood. It is conceivable that pathogens causing neglected tropical diseases play a major role, but few studies investigated this issue. Clinical management and diagnostic work-up of persistent digestive disorders in the tropics therefore remain inadequate. Hence, important aspects regarding the pathogenesis, epidemiology, clinical symptomatology and treatment options for patients presenting with persistent diarrhoea and persistent abdominal pain should be investigated in multi-centric clinical studies.; This multi-country, prospective, non-experimental case-control study will assess persistent diarrhoea (≥14 days; in individuals aged ≥1 year) and persistent abdominal pain (≥14 days; in children/adolescents aged 1-18 years) in up to 2000 symptomatic patients and 2000 matched controls. Subjects from Côte d'Ivoire, Indonesia, Mali and Nepal will be clinically examined and interviewed using a detailed case report form. Additionally, each participant will provide a stool sample that will be examined using a suite of diagnostic methods (i.e., microscopic techniques, rapid diagnostic tests, stool culture and polymerase chain reaction) for the presence of bacterial and parasitic pathogens. Treatment will be offered to all infected participants and the clinical treatment response will be recorded. Data obtained will be utilised to develop patient-centred clinical algorithms that will be validated in primary health care centres in the four study countries in subsequent studies. Our research will deepen the understanding of the importance of persistent diarrhoea and related digestive disorders in the tropics. A diversity of intestinal pathogens will be assessed for potential associations with persistent diarrhoea and persistent abdominal pain. Different diagnostic methods will be compared, clinical symptoms investigated and diagnosis-treatment algorithms developed for validation in selected="selected" primary health care centres. The findings from this study will improve differential diagnosis and evidence-based clinical management of digestive syndromes in the tropics.; ClinicalTrials.gov; identifier: NCT02105714

Supplemental Table 1 of the Genetic Diversity and Iron-Metabolism of Staphylococcus hominis isolates originating from bovine quarter milk, rectal feces, and teat apices

Multiple comparisons for the interaction term for the statistical analysis for medium (tryptic soy broth (TSB), deferrated TSB (dTSB), and deferrated TSB supplemented with equine spleen derived ferritin (dTSBF) or human recombinant lacteferrin (dTSBL)) * strain (Staphylococcus aureus ATCC 25923 (SA), S. chromogenes (SCH) IM, S. chromogenes TA, S. hominis (SH) QM, S. hominis TA, and S. hominis RF). </p