IoT Privacy Risks Revealed.

A user's devices such as their phone and computer are constantly bombarded by IoT devices and associated applications seeking connection to the user's devices. These IoT devices may or may not seek explicit user consent, thus leaving the users completely unaware the IoT device is collecting, using, and/or sharing their personal data or, only marginal informed, if the user consented to the connecting IoT device but did not read the associated privacy policies. Privacy policies are intended to inform users of what personally identifiable information (PII) data will be collected about them and the policies about how those PII data will be used and shared. This paper presents novel tools and the underlying algorithms employed by the Personal Privacy Assistant app (UTCID PPA) developed by the University of Texas at Austin Center for Identity to inform users of IoT devices seeking to connect to their devices and to notify those users of potential privacy risks posed by the respective IoT device. The assessment of these privacy risks must deal with the uncertainty associated with sharing the user's personal data. If privacy risk (R) equals the consequences (C) of an incident (i.e., personal data exposure) multiplied by the probability (P) of those consequences occurring (C × P), then efforts to control risks must seek to reduce the possible consequences of an incident as well as reduce the uncertainty of the incident and its consequences occurring. This research classifies risk according to two parameters: expected value of the incident's consequences and uncertainty (entropy) of those consequences. This research calculates the entropy of the privacy incident consequences by evaluating: (1) the data sharing policies governing the IoT resource and (2) the type of personal data exposed. The data sharing policies of an IoT resource are scored by the UTCID PrivacyCheck™, which uses machine learning to read and score the IoT resource privacy policies against metrics set forth by best practices and international regulations. The UTCID Identity Ecosystem uses empirical identity theft and fraud cases to assess the entropy of privacy incident consequences involving a specific type of personal data, such as name, address, Social Security number, fingerprint, and user location. By understanding the entropy of a privacy incident posed by a given IoT resource seeking to connect to a user's device, UTCID PPA offers actionable recommendations enhancing the user's control over IoT connections, interactions, their personal data, and, ultimately, user-centric privacy control.

Personalized Privacy Assistant: Identity Construction and Privacy in the Internet of Things.

Over time, the many different ways in which we collect and use data have become more complex as we communicate and interact with an ever-increasing variety of modern technologies. Although people often say they care about their privacy, they do not have a deep understanding of what devices around them are collecting their identity information, what identity information is being collected, and how that collected data will affect them. This research is dedicated to developing a personalized privacy assistant to help users regain control, understand their own identity management, and process and simplify the large amount of information from the Internet of Things (IoT). This research constructs an empirical study to obtain the comprehensive list of identity attributes that are being collected by IoT devices. We build a statistical model to simulate the identity theft and to help calculate the privacy risk score based on the identity attributes collected by IoT devices. We discuss how well each feature of our Personal Privacy Assistant (PPA) works and compare the PPA and related work to a list of fundamental features for privacy protection.

Involvement of AMPKα and MAPK-ERK/-JNK Signals in Docetaxel-Induced Human Tongue Squamous Cell Carcinoma Cell Apoptosis.

Cancers of the oral cavity can develop in the anatomic area extending from the lip, gum, tongue, mouth, and to the palate. Histologically, about 85-90% of oral cavity cancers are of the type squamous cells carcinomas (SCCs). The incidence of oral tongue SCC is higher in the tongue than any other anatomic area of the oral cavity. Here, we investigated the therapeutic effects and molecular mechanisms of docetaxel, which is a paclitaxel antitumor agent, on the cell growth of a human tongue SCC-derived SAS cell line. The results showed that docetaxel (10-300 nM) induced cytotoxicity and caspase-3 activity in SAS cells. Moreover, docetaxel (100 nM) promoted the expression of apoptosis-related signaling molecules, including the cleavages of caspase-3, caspase-7, and poly (ADP-ribose) polymerase (PARP). In mitochondria, docetaxel (100 nM) decreased the mitochondrial membrane potential (MMP) and Bcl-2 mRNA and protein expression and increased cytosolic cytochrome c protein expression and Bax mRNA and protein expression. In terms of mitogen-activated protein kinase (MAPK) and adenosine monophosphate-activated protein kinase (AMPK) signaling, docetaxel increased the expression of phosphorylated (p)-extracellular signal-regulated kinase (ERK), p-c-Jun N-terminal kinase (JNK), and p-AMPKα protein expression but not p-p38 protein expression. Moreover, the increase in caspase-3/-7 activity and Bax protein expression and decreased Bcl-2 protein expression and MMP depolarization observed in docetaxel-treated SAS cells could be reversed by treatment with either SP600125 (a JNK inhibitor), PD98059 (an MEK1/2 (mitogen-activated protein kinase kinase 1/2) inhibitor), or compound c (an AMPK inhibitor). The docetaxel-induced increases in p-JNK, p-ERK, and p-AMPKα protein expression could also be reversed by treatment with either SP600125, PD98059, or compound c. These results indicate that docetaxel induces human tongue SCC cell apoptosis via interdependent MAPK-JNK, MAPK-ERK1/2, and AMPKα signaling pathways. Our results show that docetaxel could possibly exert a potent pharmacological effect on human oral tongue SCC cell growth.

Norketamine, the Main Metabolite of Ketamine, Induces Mitochondria-Dependent and ER Stress-Triggered Apoptotic Death in Urothelial Cells via a Ca2+-Regulated ERK1/2-Activating Pathway.

Ketamine-associated cystitis is characterized by suburothelial inflammation and urothelial cell death. Norketamine (NK), the main metabolite of ketamine, is abundant in urine following ketamine exposure. NK has been speculated to exert toxic effects in urothelial cells, similarly to ketamine. However, the molecular mechanisms contributing to NK-induced urothelial cytotoxicity are almost unclear. Here, we aimed to investigate the toxic effects of NK and the potential mechanisms underlying NK-induced urothelial cell injury. In this study, NK exposure significantly reduced cell viability and induced apoptosis in human urinary bladder epithelial-derived RT4 cells that NK (0.01-0.5 mM) exhibited greater cytotoxicity than ketamine (0.1-3 mM). Signals of mitochondrial dysfunction, including mitochondrial membrane potential (MMP) loss and cytosolic cytochrome c release, were found to be involved in NK-induced cell apoptosis and death. NK exposure of cells also triggered the expression of endoplasmic reticulum (ER) stress-related proteins including GRP78, CHOP, XBP-1, ATF-4 and -6, caspase-12, PERK, eIF-2α, and IRE-1. Pretreatment with 4-phenylbutyric acid (an ER stress inhibitor) markedly prevented the expression of ER stress-related proteins and apoptotic events in NK-exposed cells. Additionally, NK exposure significantly activated JNK, ERK1/2, and p38 signaling and increased intracellular calcium concentrations ([Ca2+]i). Pretreatment of cells with both PD98059 (an ERK1/2 inhibitor) and BAPTA/AM (a cell-permeable Ca2+ chelator), but not SP600125 (a JNK inhibitor) and SB203580 (a p38 inhibitor), effectively suppressed NK-induced mitochondrial dysfunction, ER stress-related signals, and apoptotic events. The elevation of [Ca2+]i in NK-exposed cells could be obviously inhibited by BAPTA/AM, but not PD98059. Taken together, these findings suggest that NK exposure exerts urothelial cytotoxicity via a [Ca2+]i-regulated ERK1/2 activation, which is involved in downstream mediation of the mitochondria-dependent and ER stress-triggered apoptotic pathway, consequently resulting in urothelial cell death. Our findings suggest that regulating [Ca2+]i/ERK signaling pathways may be a promising strategy for treatment of NK-induced urothelial cystitis.

Methylmercury Induces Mitochondria- and Endoplasmic Reticulum Stress-Dependent Pancreatic ß-Cell Apoptosis via an Oxidative Stress-Mediated JNK Signaling Pathway.

Methylmercury (MeHg), a long-lasting organic pollutant, is known to induce cytotoxic effects in mammalian cells. Epidemiological studies have suggested that environmental exposure to MeHg is linked to the development of diabetes mellitus (DM). The exact molecular mechanism of MeHg-induced pancreatic ß-cell cytotoxicity is still unclear. Here, we found that MeHg (1-4 µM) significantly decreased insulin secretion and cell viability in pancreatic ß-cell-derived RIN-m5F cells. A concomitant elevation of mitochondrial-dependent apoptotic events was observed, including decreased mitochondrial membrane potential and increased proapoptotic (Bax, Bak, p53)/antiapoptotic (Bcl-2) mRNA ratio, cytochrome c release, annexin V-Cy3 binding, caspase-3 activity, and caspase-3/-7/-9 activation. Exposure of RIN-m5F cells to MeHg (2 µM) also induced protein expression of endoplasmic reticulum (ER) stress-related signaling molecules, including C/EBP homologous protein (CHOP), X-box binding protein (XBP-1), and caspase-12. Pretreatment with 4-phenylbutyric acid (4-PBA; an ER stress inhibitor) and specific siRNAs for CHOP and XBP-1 significantly inhibited their expression and caspase-3/-12 activation in MeHg-exposed RIN-mF cells. MeHg could also evoke c-Jun N-terminal kinase (JNK) activation and reactive oxygen species (ROS) generation. Antioxidant N-acetylcysteine (NAC; 1mM) or 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (trolox; 100 µM) markedly prevented MeH-induced ROS generation and decreased cell viability in RIN-m5F cells. Furthermore, pretreatment of cells with SP600125 (JNK inhibitor; 10 µM) or NAC (1 mM) or transfection with JNK-specific siRNA obviously attenuated the MeHg-induced JNK phosphorylation, CHOP and XBP-1 protein expression, apoptotic events, and insulin secretion dysfunction. NAC significantly inhibited MeHg-activated JNK signaling, but SP600125 could not effectively reduce MeHg-induced ROS generation. Collectively, these findings demonstrate that the induction of ROS-activated JNK signaling is a crucial mechanism underlying MeHg-induced mitochondria- and ER stress-dependent apoptosis, ultimately leading to ß-cell death.

Therapeutic Effect of a Newly Isolated Lytic Bacteriophage against Multi-Drug-Resistant Cutibacterium acnes Infection in Mice.

Acne vulgaris, which is mostly associated with the colonization of Cutibacterium acnes (C. acnes), is a common skin inflammatory disease in teenagers. However, over the past few years, the disease has extended beyond childhood to chronically infect approximately 40% of adults. While antibiotics have been used for several decades to treat acne lesions, antibiotic resistance is a growing crisis; thus, finding a new therapeutic target is urgently needed. Studies have shown that phage therapy may be one alternative for treating multi-drug-resistant bacterial infections. In the present study, we successfully isolated a C. acnes phage named TCUCAP1 from the skin of healthy volunteers. Morphological analysis revealed that TCUCAP1 belongs to the family Siphoviridae with an icosahedral head and a non-contractile tail. Genome analysis found that TCUCAP1 is composed of 29,547 bp with a G+C content of 53.83% and 56 predicted open reading frames (ORFs). The ORFs were associated with phage structure, packing, host lysis, DNA metabolism, and additional functions. Phage treatments applied to mice with multi-drug-resistant (MDR) C.-acnes-induced skin inflammation resulted in a significant decrease in inflammatory lesions. In addition, our attempt to formulate the phage into hydroxyethyl cellulose (HEC) cream may provide new antibacterial preparations for human infections. Our results demonstrate that TCUCAP1 displays several features that make it an ideal candidate for the control of C. acnes infections.

Selective Capture and Identification of Methicillin-Resistant Staphylococcus aureus by Combining Aptamer-Modified Magnetic Nanoparticles and Mass Spectrometry.

A nucleic acid aptamer that specifically recognizes methicillin-resistant Staphylococcus aureus (MRSA) has been immobilized on magnetic nanoparticles to capture the target bacteria prior to mass spectrometry analysis. After the MRSA species were captured, they were further eluted from the nanoparticles and identified using matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). The combination of aptamer-based capture/enrichment and MS analysis of microorganisms took advantage of the selectivity of both techniques and should enhance the accuracy of MRSA identification. The capture and elution efficiencies for MRSA were optimized by examining factors such as incubation time, temperature, and elution solvents. The aptamer-modified magnetic nanoparticles showed a capture rate of more than 90% under the optimized condition, whereas the capture rates were less than 11% for non-target bacteria. The as-prepared nanoparticles exhibited only a 5% decrease in the capture rate and a 9% decrease in the elution rate after 10 successive cycles of utilization. Most importantly, the aptamer-modified nanoparticles revealed an excellent selectivity towards MRSA in bacterial mixtures. The capture of MRSA at a concentration of 102 CFU/mL remained at a good percentage of 82% even when the other two species were at 104 times higher concentration (106 CFU/mL). Further, the eluted MRSA bacteria were successfully identified using MALDI mass spectrometry.

Identification of carbonylated proteins in a bactericidal process induced by curcumin with blue light irradiation on imipenem-resistant Acinetobacter baumannii.

RATIONALE: Antimicrobial photodynamic treatment is potentially an alternative to antibiotics and is also effective against viruses, fungi and some cancers. Our previous studies have shown that blue light combined with curcumin, a chemical from the turmeric plant, exerted effective antimicrobial activity via photodynamic treatment. The study reported in this paper investigates which target proteins are affected after the treatment. METHODS: We treated imipenem-resistant Acinetobacter baumannii with blue light and curcumin and used protein carbonylation as a marker for oxidative damage. After treatment, the bacterial proteins were extracted and the protein carbonyls marked using dinitrophenylhydrazide. After enzyme digestion, we used liquid chromatography/nano-electrospray ionization (LC/nano-ESI) ion trap mass spectrometry to identify bacterial peptides from a customized database. The functional enrichment analyses of the identified proteins were performed using gene ontology annotation and the STRING protein-protein interaction network. RESULTS: The application of curcumin with blue light showed good antibacterial activity against imipenem-resistant A. baumannii. Using a shotgun proteomics approach, the carbonylated proteins in A. baumannii caused by the photolytic curcumin were identified. The results showed that the proteins related to membrane structures, translation and response to oxidative stress were preferentially modified. CONCLUSIONS: The photolytic curcumin treatment could be a potential alternative to antibiotics for bacterial infection. In this study, the shotgun proteomics strategy allows us to explore the possible bactericidal mechanisms under this oxidative stress. The result provides a reference for future studies on the enhancement of the action of photolytic curcumin.

Altered susceptibility to air sampling stress by filtration is related to colistin resistance development in Acinetobacter baumannii.

The accurate quantification of antibiotic-resistant bacteria in indoor air has recently attracted increasing attention. Here, we investigated whether the susceptibility of a nosocomial infection-related microbe, Acinetobacter baumannii, to strong sampling stress caused by Nuclepore filter changes as it develops resistance to a drug called colistin. Both colistin-sensitive A. baumannii (CSAB) and colistin-resistant A. baumannii (CRAB) are generally desiccation-resistant strains that can be collected by filter sampling. However, the resistance of CRAB to the three combined stresses (aerosolization, impaction, and desiccation) caused by filter sampling was 1.8 times lower than that of CSAB (P < 0.05). The sampling stresses caused by filter sampling not only reduced the culturability of A. baumannii but also destroyed proteins to result in cellular protein leakage. CRAB released 17%-38% more extracellular protein than did CSAB when they were both subjected to desiccation stress for 240 minutes (P < 0.01). The combination of using a sampling flow rate of 20 L/min and sampling for 60 minutes with a Nuclepore filter with open-face cassettes (OFCs) is recommended for collecting airborne A. baumannii. A Nuclepore filter operated with closed-face cassettes (CFCs) significantly decreased the culturability of CRAB due to desiccation effects.

Altered susceptibility to the bactericidal effect of photocatalytic oxidation by TiO2 is related to colistin resistance development in Acinetobacter baumannii.

Multidrug-resistant Acinetobacter baumannii is a well-documented pathogen associated with hospital-acquired infections. In addition to multidrug resistance, A. baumannii can also become resistant to colistin, the antibiotic treatment of last resort, by the loss of the lipopolysaccharide from its outer membrane. Here, we demonstrate that the development of colistin resistance also increases the resistance of A. baumannii to titanium dioxide (TiO2) photocatalysis. Both colistin-sensitive A. baumannii (CSAB) and colistin-resistant A. baumannii (CRAB) were inactivated by TiO2 when irradiated by ultraviolet A (UV-A). The resistance of CRAB to TiO2 photocatalysis was 1.5 times higher than that of CSAB, as determined by either culture assay or quantification of leaked proteins after photocatalysis (p < 0.05). The results of two-dimensional gel electrophoresis led to the speculation that the high resistance of CRAB may be associated with a lack of sensitive targets and oxidative enzymes. This hypothesis was confirmed by antimicrobial assays with 25 mM hydrogen peroxide (H2O2) and 1.07 mM sodium hypochlorite (NaClO). CRAB was significantly more resistant to H2O2 and NaClO treatment than CSAB (p < 0.01), consistent with the results of the TiO2 inactivation experiment. Therefore, the antibiotic resistance profiles of bacterial strains should be considered before the use of strains as indicators to represent sanitary quality after TiO2 photocatalysis.

Molecular analysis of codon 548 in the rpoB gene involved in Mycobacterium tuberculosis resistance to rifampin.

Most Mycobacterium tuberculosis rifampin-resistant strains have been associated with mutations in an 81-bp rifampin resistance-determining region (RRDR) in the gene rpoB. However, if this region alone were targeted, rifampin-resistant strains with mutations outside the RRDR would not be detected. In this study, among 51 rifampin-resistant clinical isolates analyzed by sequencing 1,681-bp-long DNA fragments containing the RRDR, 47 isolates contained mutations within the RRDR, three isolates contained mutations both within and outside the RRDR, and only one isolate had a single missense mutation (Arg548His) located outside the RRDR. A drug susceptibility test of recombinant Mycobacterium smegmatis and M. tuberculosis isolates carrying mutated rpoB (Arg548His) showed an increased MIC for rifampin compared to that of the control strains. Modeling of the Arg548His mutant RpoB-DNA complex revealed that the His548 side chain formed a more stable hydrogen bond structure than did Arg548, reducing the flexibility of the rifampin-resistant cluster II region of RpoB, suggesting that the RpoB Arg548His mutant does not effectively interact with rifampin and results in bacterial resistance to the drug. This is the first report on the relationship between the mutation in codon 548 of RpoB and rifampin resistance in tuberculosis. The novel mutational profile of the rpoB gene described here will contribute to the comprehensive understanding of rifampin resistance patterns and to the development of a useful tool for simple and rapid drug susceptibility tests.

Prevalence and mapping of a plasmid encoding a type IV secretion system in Acinetobacter baumannii.

We investigated the prevalence of a type IV secretion system (T4SS)-bearing plasmid among clinical isolates of carbapenem-resistant Acinetobacter baumannii (CRAB) using plasmid replicon typing. The complete sequence of a T4SS-bearing plasmid, pAB_CC, isolated from A. baumannii TYTH-1 was determined, and a comparative analysis of the T4SS gene modules was performed. Of the 129 isolates studied, GR6 (repAci6) was the most common (45 of 96 isolates) and was strongly linked with the T4SS. A comparative analysis of the T4SS locus in seven plasmid genomes, including pAB_CC, pACICU2, pABKp1, pABTJ1, p1BJAB0714, p2BJAB0868, and p2ABTCDC0715, indicated that fourteen genes on these plasmids were highly conserved compared to those of the F plasmid. Additionally, the chromosomes in the seven representative isolates may be evolutionarily distinct from their intrinsic T4SS-bearing plasmids, suggesting that the two T4SS lineages emerged long before the appearance of EC II. These two lineages are now widespread in A. baumannii strains.

Antimycobacterial Activities of Endolysins Derived From a Mycobacteriophage, BTCU-1.

The high incidence of Mycobacterium infection, notably multidrug-resistant M. tuberculosis infection, has become a significant public health concern worldwide. In this study, we isolate and analyze a mycobacteriophage, BTCU-1, and a foundational study was performed to evaluate the antimycobacterial activity of BTCU-1 and its cloned lytic endolysins. Using Mycobacterium smegmatis as host, a mycobacteriophage, BTCU-1, was isolated from soil in eastern Taiwan. The electron microscopy images revealed that BTCU-1 displayed morphology resembling the Siphoviridae family. In the genome of BTCU-1, two putative lytic genes, BTCU-1_ORF7 and BTCU-1_ORF8 (termed lysA and lysB, respectively), were identified, and further subcloned and expressed in Escherichia coli. When applied exogenously, both LysA and LysB were active against M. smegmatis tested. Scanning electron microscopy revealed that LysA and LysB caused a remarkable modification of the cell shape of M. smegmatis. Intracellular bactericidal activity assay showed that treatment of M. smegmatis-infected RAW 264.7 macrophages with LysA or LysB resulted in a significant reduction in the number of viable intracellular bacilli. These results indicate that the endolysins derived from BTCU-1 have antimycobacterial activity, and suggest that they are good candidates for therapeutic/disinfectant agents to control mycobacterial infections.

Transcriptome profiling in imipenem-selected Acinetobacter baumannii.

BACKGROUND: Carbapenem-resistance in Acinetobacter baumannii has gradually become a global challenge. To identify the genes involved in carbapenem resistance in A. baumannii, the transcriptomic responses of the completely sequenced strain ATCC 17978 selected with 0.5 mg/L (IPM-2 m) and 2 mg/L (IPM-8 m) imipenem were investigated using RNA-sequencing to identify differences in the gene expression patterns. RESULTS: A total of 88 and 68 genes were differentially expressed in response to IPM-2 m and IPM-8 m selection, respectively. Among the expressed genes, 50 genes were highly expressed in IPM-2 m, 30 genes were highly expressed in IPM-8 m, and 38 genes were expressed common in both strains. Six groups of genes were simultaneously expressed in IPM-2 m and IPM-8 m mutants. The three gene groups involved in DNA recombination were up-regulated, including recombinase, transposase and DNA repair, and beta-lactamase OXA-95 and homologous recombination. The remaining gene groups involved in biofilm formation were down-regulated, including quorum sensing, secretion systems, and the csu operon. The antibiotic resistance determinants, including RND efflux transporters and multidrug resistance pumps, were over-expressed in response to IPM-2 m selection, followed by a decrease in response to IPM-8 m selection. Among the genes over-expressed in both strains, blaOXA-95, previously clustered with the blaOXA-51-like family, showed 14-fold (IPM-2 m) to 330-fold (IPM-8 m) over-expression. The expression of blaOXA-95 in IPM-2 m and IPM-8 m cells was positively correlated with the rate of imipenem hydrolysis, as demonstrated through Liquid Chromatography-Mass Spectrometry/Mass Spectrometry, suggesting that blaOXA-95 plays a critical role in conferring carbapenem resistance. In addition, A. baumannii shows an inverse relationship between carbapenem resistance and biofilm production. CONCLUSION: Gene recombination and blaOXA-95 play critical roles in carbapenem resistance in A. baumannii. Taken together, the results of the present study provide a foundation for future studies of the network systems associated with carbapenem resistance.

Roles of oxidative stress/JNK/ERK signals in paraquat-triggered hepatic apoptosis.

Paraquat (PQ), a toxic and nonselective bipyridyl herbicide, is one of the most extensively used pesticides in agricultural countries. In addition to pneumotoxicity, the liver is an important target organ for PQ poisoning in humans. However, the mechanism of PQ in hepatotoxicity remains unclear. In this study, we found that exposure of rat hepatic H4IIE cells to PQ (0.1-2 mM) induced significant cytotoxicity and apoptosis, which was accompanied by mitochondria-dependent apoptotic signals, including loss of mitochondrial membrane potential (MMP), cytosolic cytochrome c release, and changes in the Bcl-2/Bax mRNA ratio. Moreover, PQ (0.5 mM) exposure markedly induced JNK and ERK1/2 activation, but not p38-MAPK. Blockade of JNK and ERK1/2 signaling by pretreatment with the specific pharmacological inhibitors SP600125 and PD98059, respectively, effectively prevented PQ-induced cytotoxicity, mitochondrial dysfunction, and apoptotic events. Additionally, PQ exposure stimulated significant oxidative stress-related signals, including reactive oxygen species (ROS) generation and intracellular glutathione (GSH) depletion, which could be reversed by the antioxidant N-Acetylcysteine (NAC). Buffering the oxidative stress response with NAC also effectively abrogated PQ-induced hepatotoxicity, MMP loss, apoptosis, and phosphorylation of JNK and ERK1/2 protein, however, the JNK or ERK inhibitors did not suppress ROS generation in PQ-treated cells. Collectively, these results demonstrate that PQ exposure induces hepatic cell toxicity and death via an oxidative stress-dependent JNK/ERK activation-mediated downstream mitochondria-regulated apoptotic pathway.

Diagnosis of ß-lactam resistance in Acinetobacter baumannii using shotgun proteomics and LC-nano-electrospray ionization ion trap mass spectrometry.

Acinetobacter baumannii is an important nosocomial pathogen that often affects critically ill patients in intensive care units. ß-Lactam antibiotics are the most commonly prescribed drugs for infectious diseases caused by A. baumannii. Our aim is to develop an accurate and rapid shotgun proteomics method for the identification of ß-lactam-resistant A. baumannii pathogens. In the present study, we used automated data-dependent scanning on a nano-LC/ion trap mass spectrometer to characterize proteotypic peptides of A. baumannii. Then, we used SEQUEST software to search specific databases, the ß-lactam-resistance protein database of A. baumannii (BRPDAB). We successfully found a number of associated antibiotic-resistant proteins, including AmpC, ß-lactamase, and carO, in clinical resistant strains of A. baumannii and differentiated them from wild-type A. baumannii strains. We used the results of the search to identify A. baumannii pathogens and found a ß-lactam-resistant clinical strain of A. baumannii using Uniprot annotations, Gene Ontology (GO), and BLAST bioinformatics tools. This proteomic study will provide a platform for the rapid diagnosis of wild-type and resistant strains of A. baumannii, which would be useful for the medical treatment of these strains.

Potential of bacteriophage ΦAB2 as an environmental biocontrol agent for the control of multidrug-resistant Acinetobacter baumannii.

BACKGROUND: Multidrug-resistant Acinetobacter baumannii (MDRAB) is associated with nosocomial infections worldwide. To date, the use of a phage to prevent infections caused by MDRAB has not been demonstrated. RESULTS: The MDRAB-specific phage ϕAB2 was stable at 4°C and pH 7 in 0.5% chloroform solution, and showed a slight decrease in plaque-forming units (PFU)/ml of 0.3-0.9 log after 330 days of storage. The addition of ϕAB2 at a concentration of at least 105 PFU/ml to an A. baumannii M3237 suspension killed >99.9% of A. baumannii M3237 after 5 min, regardless of A. baumannii M3237 concentration (104, 105, or 106 colony-forming units (CFU)/ml). The addition of ϕAB2 at a concentration of 108 PFU/slide (>107 PFU/cm²) to glass slides containing A. baumannii M3237 at 104, 105, or 106 CFU/slide, significantly reduced bacterial numbers by 93%, 97%, and 99%, respectively. Thus, this concentration is recommended for decontamination of glass surfaces. Moreover, infusion of ϕAB2 into 10% glycerol exhibited strong anti-MDRAB activity (99.9% reduction), even after 90 days of storage. Treatment of a 10% paraffin oil-based lotion with ϕAB2 significantly reduced (99%) A. baumannii M3237 after 1 day of storage. However, ϕAB2 had no activity in the lotion after 1 month of storage. CONCLUSIONS: Phages may be useful for reducing MDRAB contamination in liquid suspensions or on hard surfaces. Phages may also be inoculated into a solution to produce an antiseptic hand wash. However, the phage concentration and incubation time (the duration of phage contact with bacteria) should be carefully considered to reduce the risk of MDRAB contamination.

Recent developments in detection and therapeutic approaches for antibiotic-resistant bacterial infections.

Owing to the widespread emergence and proliferation of antibiotic-resistant bacteria, the therapeutic benefits of antibiotics have been reduced. In addition, the ongoing evolution of multidrug-resistant pathogens poses a challenge for the scientific community to develop sensitive analytical methods and innovative antimicrobial agents for the detection and treatment of drug-resistant bacterial infections. In this review, we have described the antibiotic resistance mechanisms that occur in bacteria and summarized the recent developments in detection strategies for monitoring drug resistance using different diagnostic methods in three aspects, including electrostatic attraction, chemical reaction, and probe-free analysis. Additionally, to understand the effective inhibition of drug-resistant bacterial growth by recent nano-antibiotics, the underlying antimicrobial mechanisms and efficacy of biogenic silver nanoparticles and antimicrobial peptides, which have shown promise, and the rationale, design, and potential improvements to these methods are also highlighted in this review. Finally, the primary challenges and future trends in the rational design of facile sensing platforms and novel antibacterial agents against superbugs are discussed.

Evaluating Antioxidant Performance, Biosafety, and Antimicrobial Efficacy of Houttuynia cordata Extract and Microwave-Assisted Synthesis of Biogenic Silver Nano-Antibiotics.

From the traditional Chinese medicine point of view, although Houttuynia cordata extract (HCE) possesses an incredible amount of phytonutrients and exhibits antioxidant activities, excessive doses of HCE can cause danger to organisms and lead to death. In this study, we first examine HCE's overall phenolic and flavonoid content, antioxidant efficacy, and antibacterial activity. Results show that HCE is suitable as a bio-reducing agent for the microwave-assisted synthesis of silver nanoparticles (HCE-AgNPs) with enhanced antioxidant and antimicrobial performance. Under an optimized microwave condition (i.e., 100 °C for 10 min), the HCE-stabilized AgNPs were confirmed with a UV-visible peak at 430 nm and 19.7 ± 4.2 nm in size. Physicochemical properties of HCE-AgNPs were extensively characterized by zeta-potential, FT-IR, XRD, and XPS measurements. Compared to the HC extract counterpart, HCE-AgNPs display superior antioxidant activity, higher DPPH scavenging efficiency, and enhanced broad-spectrum bactericidal activity to inhibit the growth of all tested bacterial strains at doses of 2 µg/mL. Biosafety evaluation indicated that HCE-AgNPs are noncytotoxic on human red blood cells. These data show that the microwave synthesis of AgNPs exhibits a great antioxidant ability, superior antibacterial activity, and a trivial hemolytic effect, providing another bactericidal therapy strategy to address the increasing healthcare-associated infections.

Idiopathic Mesenteric Phlebosclerosis: A Single-Institute Experience in Taiwan.

BACKGROUND: Idiopathic mesenteric phlebosclerosis is a rare condition with unclear pathogenesis. This study aimed to investigate the clinical features, diagnostic modalities, treatments, and outcomes of idiopathic mesenteric phlebosclerosis patients in Taiwan. METHODS: Idiopathic mesenteric phlebosclerosis patients diagnosed by the typical characteristic of tree-like mesenteric venous calcifications on plain abdominal radiography or computed tomography between January 1992 and July 2021 were retrospectively analyzed. RESULTS: Totally, 36 idiopathic mesenteric phlebosclerosis patients were enrolled (50% females; mean age, 61.6 years). Among the included patients, 26 (72.2%) and 10 (27.7%) were symptomatic and asymptomatic, respectively. Abdominal pain (61.1%) accounted for the majority of all symptoms, followed by fever, diarrhea, and bloody stools. Our results showed that 83.3% of patients had at least 1 risk factor, whereas 16.6% of patients had none. Moreover, among the included patients, 36.1%, 44.4%, 50.0%, 38.8%, and 8.3% had cardiovascular disease, chronic renal disease, cancer, chronic liver disease, and diabetes mellitus, respectively. Our findings showed 94.4% of patients were diagnosed via abdominal computed tomography and plain abdominal radiography, whereas 5.6% of patients were diagnosed via plain abdominal radiography. The ascending colon was the most commonly involved site (100%). Our findings showed that 91.6% of patients experienced good recovery after conservative treatment, except for the 3 who died of sepsis and respiratory failure. By contrast, 8.3% of idiopathic mesenteric phlebosclerosis patients underwent colectomy. The average follow-up duration was 62.5 months. CONCLUSIONS: Idiopathic mesenteric phlebosclerosis remains a rare disease in Taiwan. Plain abdominal radiography and computed tomography can be utilized for establishing a definite diagnosis. Conservative treatment is usually adequate for most patients, with surgical treatment only indicated for severe cases.