Subclinical mastitis is a persistent problem in dairy farms worldwide. Environmental Escherichia coli is the bacterium predominantly responsible for this condition. In Thailand, subclinical mastitis in dairy cows is usually treated with various antibiotics, which could lead to antibiotic resistance in bacteria. E. coli is also a reservoir of many antibiotic resistance genes, which can be conveyed to other bacteria. In this study, the presence of E. coli in milk and water samples was reported, among which enteropathogenic E. coli was predominant, followed by enteroaggregative E. coli and enterohemorrhagic E. coli, which was found only in milk samples. Twenty-one patterns of antibiotic resistance were identified in this study. Ampicillin- and carbenicillin-resistant E. coli was the most common among the bacterial isolates from water samples. Meanwhile, resistance to ampicillin, carbenicillin, and sulfamethoxazole-trimethoprim was the pattern found most commonly in the E. coli from milk samples. Notably, only the E. coli from water samples possessed ESBL phenotype and carried antibiotic resistance genes, blaTEM and blaCMY-2. This indicates that pathogenic E. coli in dairy farms is also exposed to antibiotics and could potentially transfer these genes to other pathogenic bacteria under certain conditions.

Staphylococcus argenteus, a novel species of the genus Staphylococcus or a member of the S. aureus complex, is closely related to S. aureus and is usually misidentified. In this study, the presence of S. argenteus in isolated S. aureus was investigated in 67 rabbits with abscess lesions during 2014-2016. Among 19 S. aureus complex isolates, three were confirmed to be S. argenteus by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, nonribosomal peptide synthetase gene amplification, and multilocus sequence type. All S. aureus complex isolates, including the S. aureus isolates, were examined for their antimicrobial resistance phenotype by disk diffusion and for their resistance genotype by PCR assays. Among the S. argenteus isolates, one was susceptible to all antimicrobial drugs and the other two were resistant to penicillin and doxycycline. In contrast, most S. aureus isolates were resistant to penicillin (37.5%), and gentamicin (12.5%). Moreover, S. aureus isolates harbored the blaZ, mecA, aacA-aphD, and mrs(A) as well as mutations of gyrA and grlA, but S. argenteus isolates carried solely the blaZ. S. argenteus isolates were investigated for enterotoxin (sea-sed) and virulence genes by PCR. One isolate carried sea, sec, and sed, whereas the other two isolates carried only sea or sed. No isolate carried seb and see. All three S. argenteus isolates carried hla, hlb, and clfA, followed by pvl, whereas coa, spa (IgG-binding region), and spa (x region) were not detected in the three isolates. This paper presents the first identification of S. argenteus from rabbits in Thailand. S. argenteus might be pathogenic because the isolates carried virulence genes. Moreover, antimicrobial resistance was observed. Investigations of this new bacterial species should be conducted in other animal species as well as in humans.

Embryonic tissue and organ development are initiated from three embryonic germ layers: ectoderm (skin and neuron), mesoderm (blood, bone, muscle, cartilage and fat) and endoderm (respiratory and digestive tract). In former times, it was believed that cell types in each germ layer are specific and do not cross from one to another throughout life. A new finding is that one tissue lineage can differentiate across to another tissue lineage, and this is termed transdifferentiation. We were interested in studying the transdifferentiation of skinderived precursor cells (ectoderm layer) to osteoblastic cells (mesoderm layer). Human skin-derived precursor cells (hSKP) were isolated and induced into an osteoblastic lineage using osteogenic induction medium (α-MEM plus 10% fetal bovine serum supplemented with ascorbic acid, β-glycerophosphate and dexamethasone). The specific characteristics of osteoblastic cells, including the expression of enzyme alkaline phosphatase, the deposition of mineral and the expression of osterix, bone sialoprotein and osteocalcin, were detected only from the inductive group. The results in our study show that SKP from human skin are a practically available source for osteogenesis. The samples are easily obtainable for autologous use with a high expansion capacity.

No abstract

The existence of neuroinflammation and oxidative stress surrounding amyloid beta (Aβ) plaques, a hallmark of Alzheimer’s disease (AD), has been demonstrated and may result in the activation of neuronal death and inhibition of neurogenesis. Therefore, dysregulation of neuroinflammation and oxidative stress is one possible therapeutic target for AD. Kaempferia parviflora Wall. ex Baker (KP), a member of the Zingiberaceae family, possesses health-promoting benefits including anti-oxidative stress and anti-inflammation in vitro and in vivo with a high level of safety; however, the role of KP in suppressing Aβ-mediated neuroinflammation and neuronal differentiation has not yet been investigated. The neuroprotective effects of KP extract against Aβ42 have been examined in both monoculture and co-culture systems of mouse neuroectodermal (NE-4C) stem cells and BV-2 microglia cells. Our results showed that fractions of KP extract containing 5,7-dimethoxyflavone, 5,7,4′-trimethoxyflavone, and 3,5,7,3′,4′-pentamethoxyflavone protected neural stem cells (both undifferentiated and differentiated) and microglia activation from Aβ42-induced neuroinflammation and oxidative stress in both monoculture and co-culture system of microglia and neuronal stem cells. Interestingly, KP extracts also prevented Aβ42-suppressed neurogenesis, possibly due to the contained methoxyflavone derivatives. Our data indicated the promising role of KP in treating AD through the suppression of neuroinflammation and oxidative stress induced by Aβ peptides.