The influence of plant extracts on viability of ST3 and ST7 subtypes of Blastocystis sp

Blastocystis sp. is one of the most frequently detected protozoa during stool specimen examination. In the last decade, the studies about the pathogenic potential of Blastocystis sp. have intensified. Additionally, treatment approaches against this parasite are still disputable. The study aimed to investigate the in vitro activity of the substances of natural origin against two subtypes (ST) of Blastocystis sp.-ST3 and ST7. Garlic and turmeric extracts exhibited the highest inhibitory effect in relation to the ST3 viability. While horseradish and turmeric were found to be the most effective extracts to the ST7 viability. The study showed that ginger, garlic, horseradish, and turmeric extracts have potent antimicrobial activity against Blastocystis ST3 and ST7, with the half-maximal inhibitory concentration (IC50) ranging from 3.8 to 4.8 µg/ml and from 3.3 to 72.0 µg/ml, respectively, and thus may be useful in the prevention and control of Blastocystis infections. Additionally, this research confirmed that Blastocystis ST7 is more resistant to the selected plant extracts treatment than Blastocystis ST3 which in consequence may bring some difficulties in its eradication.

An lnu(A)-Carrying Multi-Resistance Plasmid Derived from Sequence Type 3 Methicillin-Resistant Staphylococcus lugdunensis May Contribute to Antimicrobial Resistance in Staphylococci

Methicillin-resistant Staphylococcus lugdunensis (MRSL) strains showing resistance to several common antibiotics have been reported recently. Sequence type (ST) 3 MRSL carrying SCCmec types IV, V, or Vt is the major lineage associated with health care-associated infections. We aimed to investigate the distribution and dissemination of antimicrobial resistance determinants in this lineage. Two representative ST3-MRSL strains, CGMH-SL131 (SCCmec V) and CGMH-SL138 (SCCmec IV), were subjected to whole-genome sequencing. Detection of antibiotic resistance genes and screening of susceptibility patterns were performed for 30 ST3-MRSL and 16 ST6-MRSL strains via PCR and standard methods. Except for mecA and blaZ, antimicrobial resistance genes were located within two plasmids: a 28.6 kb lnu(A)-carrying plasmid (pCGMH_SL138) in CGMH-SL138 and a 26 kb plasmid carrying non-lnu(A) resistance genes (pCGMH_SL131) in CGMH-SL131. Both plasmids shared common genetic features with multiple copies of IS257 flanked by genes conferring resistance to aminoglycoside (aacA-aphD and aadD), TET (tetk), and cadmium (cadDX) and tolerance to chlorhexidine (qacA/R); however, only pCGMH_SL138 harbored lnu(A) that conferred resistance to lincomycin and rep13 that encodes a replication initiation protein. Unlike ST6-MRSL, none of the ST3-MRSL isolates contained the ermA gene. Instead, most isolates harbored lnu(A) (20/30, 66.7%), and several other resistance genes found on pCGMH_SL138. These isolates and transformants containing pCGMH_SL138 exhibited susceptibility to ERY and higher MICs for lincomycin and aforementioned antibiotics. A novel lnu(A)-carrying plasmid, pCGMH_SL138, that harbored a multiresistance gene cluster, was identified in ST3-MRSL strains and may contribute to the dissemination of antibiotic resistance in staphylococci.

Evaluation of association with subtypes and alleles of Blastocystis with chronic spontaneous urticaria

Blastocystis is a single-celled parasite commonly found in humans and its pathogenic role is still controversial. In recent years, some studies have suggested that Blastocystis may be a possible agent of gastrointestinal and dermatological symptoms such as acute or chronic urticaria, angioedema, rash, itch, palmoplantar, and diffuse pruritus. We aimed to investigate whether there is a relationship between Blastocystis subtypes and alleles in patients with chronic spontaneous urticaria (CSU) as a case-control study. In this study, stool samples were collected from patients with CSU (n=135) and healthy individuals (n=54). The presence of Blastocystis was investigated using the direct saline smear, Lugol's iodine staining, trichrome staining, Jones' medium culture and PCR assays in stool samples and subtypes (STs) were determined by sequencing according to DNA barcoding. The presence of Blastocystis was identified in 30.4% (64/210) the stool samples, including 31.9% (43/135) of the patients with CSU and 14.8% (8/54) of the control group. Moreover, it was found statistically significant the presence of Blastocystis in terms of both groups (p<0.018). ST3 was detected in 45.9% and 62.5 % as the most prevalent subtype the patients with CSU and the control group, respectively. ST1 (18.9%), ST2 (27%) and ST7 (8.1%) was identified in the patients with CSU group. There was no statistically significant correlation between Blastocystis subtypes and both the groups (p<0.240, p<0.323). Allele 4 for ST1; alleles 9, 10, 11 and 12 for ST2; alleles 34, 36 and 38 for ST3; alleles 41 and 101 for ST7 were detected. Allele 34 (ST3) was found significant in the patients with CSU as compared with control group (p<0.020). Moreover, statistically significant association was found between total IgE value and the certain subtypes (ST2 and ST3) (p<0.0001). As a result of this study, the presence of Blastocystis ST3 allele 34 significantly associated with chronic spontaneous urticaria was revealed.

Occurrence of Blastocystis-subtypes in patients from Italy revealed association of ST3 with a healthy gut microbiota

An epidemiological survey on Blastocystis was carried out enrolling a total of 2524 subjects referred to the Umberto I Academic Hospital in Rome, for the routine parasitological exams, during 2017–2018. The studied population included a sample of immunocompromised individuals (N = 130) followed at the same hospital.

DNA sequencing of the small subunit rRNA gene (SSU rDNA) locus was performed on samples positive to the coproparasitological analysis to molecular characterize the Blastocystis-subtypes.

Microscopical analysis detected Blastocystis in 192/2524 (7.6%) of the enrolled subjects. It was the organism most frequently identified in the analysed faecal samples diagnosed in single infection (5.6%) or in co-infection with other enteric protozoa (2%). Furthermore, it was found mainly in immunocompromised patients (22.3%) compared to immunocompetent ones (6.8%).

As expected, ST3 was the most occurring subtype identified in 40% of the subjects, followed by ST1 (29%), ST2 (16%), ST4 (12%), and ST7 (3%).

Next-generation sequencing (NGS) of the 16S rDNA was performed on a sub-sample of Blastocystis-ST3-carriers, homogenous by age and gender, as well as on Blastocystis-free subjects, to profile and compare their gut bacterial composition. A higher bacterial diversity was found in ST3-Blastocystis-carriers, which exhibited a high abundance of Prevotella, Methanobrevibacter and Ruminococcus while, a high percentage of Bacteroides was found in Blastocystis-free subjects.

This study evidenced the presence of Blastocystis in 7.6% of faecal samples in Italy and a high circulation of the protist among immunocompromised patients (22.3%). Molecular characterization of positive samples evidenced the occurrence of five different subtypes, including zoonotic ST such as the ST7, highlighting the risk of transmission from animals. Study of the gut microbiota composition confirms previous evidences according to which, the colonisation by Blastocystis would be linked with an eubiotic gut characterized by potentially beneficial species such as Prevotella and Ruminococcus, rather than with a dysbiotic state, with a high abundance of Enterobacteriaceae, and corroborated the role of the protist as “an old friend” of the human gut.

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Microscopical analysis detected Blastocystis in 7.6% subjects in Italy.

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Molecular methods allowed the identification of 5 STs (ST1, ST2, ST3, ST4, ST7).

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ST3 resulted the most frequent subtype.

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NGS of the 16S rDNA gene was performed in Blastocystis-ST3-carriers.

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Blastocystis-ST3 resulted correlated to an eubiotic gut characterized by potentially beneficial species.

Experimental Investigation on Friction and Wear Behavior of the Vertical Spindle and V-belt of a Cotton Picker

This study deals with the friction and wear behavior of the vertical spindle and V-belt to improve the reliability, operation and to extend the service life of a cotton picker. The vertical spindle made of low-carbon steel (ST3) was treated by the ultrasonic nanocrystal surface modification (UNSM) technique to control the friction and wear behavior. It was found that the UNSM technique reduced surface roughness and increased surface hardness of the vertical spindle. The friction and wear behavior of the vertical spindle and V-belt was assessed by carrying out tribological tests and the results showed that the UNSM-treated vertical spindle generated a higher friction coefficient compared to the untreated one due to having less slip. In case of wear resistance, unmeasurable wear occurred on the surface of the vertical spindle due to its significant high hardness compared to the hardness of the V-belt that came into contact with the vertical spindle in relative motion. Hence, the wear behavior and mechanisms of the V-belts were systematically investigated and also discussed based on the wear track profiles and micrographs. It can be concluded that the application of the UNSM technique to the vertical spindle may contribute to improve the performance of cotton pickers by reducing the slip and prolonging the service life.

Cardiothoracic-themed core surgical training programs in Scotland

Cardiothoracic surgery generates an impression that only the most committed should pursue it. The book TSRA Review of Cardiothoracic Surgery (Thoracic Surgery Residents Association) is organized around topics core surgical trainees (ie, residents) are expected to understand and master, particularly as surgical selection and training has undergone recent change.