Acinetobacter baumannii, a Gram-negative bacterium, is an important nosocomial pathogen. Colistin-resistant A. baumannii is becoming a new concern, since colistin is one of the last-line antibiotics for infections by carbapenem-resistant A. baumannii. From 452 carbapenem-resistant isolates collected in a teaching hospital in Taipei, Taiwan, we identified seven that were resistant to colistin. Carbapenem resistance in these isolates is attributed to the presence of carbapenemase gene blaOXA-23 in their genomes. Colistin resistance is presumably conferred by mutations in the sensor kinase domain of PmrB found in these isolates, which are known to result in modification of colistin target lipid A via the PmrB–PmrA–PmrC signal transduction pathway. Overexpression of pmrC, eptA, and naxD was observed in all seven isolates. Colistin resistance mediated by pmrB mutations has never been reported in Taiwan. One of the seven isolates contained three mutations in lpxD and exhibited an altered lipopolysaccharide profile, which may contribute to its colistin resistance. No significant difference in growth rates was observed between the isolates and the reference strain, suggesting no fitness cost of colistin resistance. Biofilm formation abilities of the isolates were lower than that of the reference. Interestingly, one of the isolates was heteroresistant to colistin. Four of the isolates were significantly more virulent to wax moth larvae than the reference.

Microtubule-targeting agents (MTAs) are widely used in cancer chemotherapy, but the therapeutic responses significantly vary among different tumor types. Protein kinase RNA-like endoplasmic reticular (ER) kinase (PERK) is an ER stress kinase, and the role of PERK in the anticancer effects of MTAs is still undefined. In the present study, taxol (TAX) and nocodazole (NOC) significantly induced apoptosis with increased expression of phosphorylated PERK (pPERK; Tyr980) in four human colon cancer cell lines, including HCT-15, COLO205, HT-20, and LOVO cells. Induction of G2/M arrest by TAX and NOC with increases in phosphorylated Cdc25C and cyclin B1 protein were observed in human colon cancer cells. Application of the c-Jun N-terminal kinase (JNK) inhibitors SP600125 (SP) and JNK inhibitor V (JNKI) significantly reduced TAX- and NOC-induced apoptosis and G2/M arrest of human colon cancer cells. Interestingly, TAX- and NOC-induced pPERK (Tyr980) protein expression was inhibited by adding the JNK inhibitors, SP and JNKI, and application of the PERK inhibitor GSK2606414 (GSK) significantly reduced apoptosis and G2/M arrest by TAX and NOC, with decreased pPERK (Tyr980) and pJNK, phosphorylated Cdc25C, and Cyc B1 protein expressions in human colon cancer cells. Decreased viability by TAX and NOC was inhibited by knockdown of PERK using PERK siRNA in COLO205 and HCT-15 cells. Disruption of the mitochondrial membrane potential and an increase in B-cell lymphoma-2 (Bcl-2) protein phosphorylation (pBcl-2; Ser70) by TAX and NOC were prevented by adding the PERK inhibitor GSK and JNK inhibitor SP and JNKI. A cross-activation of JNK and PERK by TAX and NOC leading to anti-CRC actions including apoptosis and G2/M arrest was first demonstrated herein.

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Urinary tract infections (UTIs) are common in clinics and hospitals and are associated with a high economic burden. Enterobacterium Klebsiella pneumoniae is a prevalent agent causing UTIs. A high prevalence of carbapenem-resistant K. pneumoniae (CRKP) has emerged recently and is continuing to increase. Seventeen urinary CRKP isolates collected at a teaching hospital in Taiwan from December 2016 to September 2017 were analyzed to elucidate their drug resistance mechanisms. Two-thirds of the isolates were obtained from outpatients. Antimicrobial susceptibility tests demonstrated multidrug resistance in all the isolates. Multilocus sequence typing analysis showed high diversity among the isolates. PCR analysis demonstrated the presence of carbapenemases in three isolates. All isolates carried at least one other extended-spectrum β-lactamase, including TEM, DHA, and CTX-M. Fifteen isolates contained mutations in one of the outer membrane porins that were assessed. The expression levels of the acrB and/or oqxB efflux pump genes, as determined by qRT-PCR, were upregulated in 11 isolates. Six isolates might have utilized other efflux pumps or antimicrobial resistance mechanisms. These analyses demonstrated a highly diverse population and the presence of complex resistance mechanisms in urinary isolates of K. pneumoniae.

Pendahuluan: Makanan dan minuman yang tidak memenuhi persyaratan kesehatan jika dikonsumsi  akan menimbulkan gangguan kesehatan seperti diare, kolera, disentri, demam tifoid dan keracunan makanan. Menurut data Kemenkes tahun 2017 kasus diare pada tahun 2016 dengan Case Fatality Rate (CFR) mencapai 3.04% dengan 6 orang meninggal dari 198 kasus. Kebersihan peralatan makan merupakan salah satu aspek dalam hygiene dan sanitasi makanan. Proses pencucian peralatan makan yang benar akan berdampak pada hygiene dan sanitasi yang baik. Spons cuci piring umumnya digunakan untuk menghilangkan sisa makanan. Sisa makanan yang terdapat pada spons akan mendukung lingkungan bakteri untuk tumbuh. Spons yang terkontaminasi dapat mengkontaminasi peralatan makan, sehingga menyebabkan penularan penyakit bawaan makanan. Studi kasus di Amerika Serikat menunjukkan bahwa terjadi hampir 38.6 juta kasus penyakit akibat penyebaran penyakit bawaan makanan. Penelitian ini bertujuan untuk mengetahui keberadaan bakteri patogen serta jenis bakteri patogen yang terdapat pada spons cuci piring pada penjual makanan. Metode: Identifikasi bakteri patogen dilakukan pada 10 spons cuci piring yang digunakan penjual makanan di Pasar Margahayu. Identifikasi bakteri menggunakan pewarnaan Gram dan uji biokimia. Hasil: Jenis bakteri patogen yang teridentifikasi adalah Escherichia coli, Staphylococcus aureus, Pseudomonas aeroginosa, Enterobacter aerogenes, dan Proteus sp. Persentase isolat yang ditemukan adalah 80% spons mengandung S. aureus, 70% mengandung E. aerogenes, 20% mengandung E.coli, 20% mengandung P.aeroginosa, dan 10% mengandung Proteus sp. Kesimpulan: sampel spons cuci piring yang telah dilakukan pewarnaan Gram dan uji biokimia menunjukkan kecurigaan terhadap koloni berwarna putih transparan adalah Proteus sp. koloni putih transparan bulat kecil adalah Enterobacter aerogenes, putih bulat besar adalah Escherichia coli, putih bulat kecil adalah Pseudomonas aeroginosa, koloni merah pada media SSA adalah Enterobacter aerogenes, dan koloni putih dengan zona kuning adalah Staphylococcus aureus.