Identification of Mycobacterium tuberculosis Resistance to Common Antibiotics: An Overview of Current Methods and Techniques.

Multidrug-resistant tuberculosis (MDR-TB) is an essential cause of tuberculosis treatment failure and death of tuberculosis patients. The rapid and reliable profiling of Mycobacterium tuberculosis (MTB) drug resistance in the early stage is a critical research area for public health. Then, most traditional approaches for detecting MTB are time-consuming and costly, leading to the inappropriate therapeutic schedule resting on the ambiguous information of MTB drug resistance, increasing patient economic burden, morbidity, and mortality. Therefore, novel diagnosis methods are frequently required to meet the emerging challenges of MTB drug resistance distinguish. Considering the difficulty in treating MDR-TB, it is urgently required for the development of rapid and accurate methods in the identification of drug resistance profiles of MTB in clinical diagnosis. This review discussed recent advances in MTB drug resistance detection, focusing on developing emerging approaches and their applications in tangled clinical situations. In particular, a brief overview of antibiotic resistance to MTB was present, referred to as intrinsic bacterial resistance, consisting of cell wall barriers and efflux pumping action and acquired resistance caused by genetic mutations. Then, different drug susceptibility test (DST) methods were described, including phenotype DST, genotype DST and novel DST methods. The phenotype DST includes nitrate reductase assay, RocheTM solid ratio method, and liquid culture method and genotype DST includes fluorescent PCR, GeneXpert, PCR reverse dot hybridization, ddPCR, next-generation sequencing and gene chips. Then, novel DST methods were described, including metabolism testing, cell-free DNA probe, CRISPR assay, and spectral analysis technique. The limitations, challenges, and perspectives of different techniques for drug resistance are also discussed. These methods significantly improve the detection sensitivity and accuracy of multidrug-resistant tuberculosis (MRT) and can effectively curb the incidence of drug-resistant tuberculosis and accelerate the process of tuberculosis eradication.

Singular perturbation analysis in a coupled Chua's circuit with diffusion.

This paper is concerned with the traveling wave solutions of a singularly perturbed system, which arises from the coupled arrays of Chua's circuit. By the geometric singular perturbation theory and invariant manifold theory, we prove that there exists a heteroclinic cycle consisting of the traveling front and back waves with the same wave speed. In particular, the expression of corresponding wave speed is also obtained. Furthermore, we show that the chaotic behavior induced by this heteroclinic cycle is hyperchaos.

Quantitative Polymerase Chain Reaction (qPCR)-Based Rapid Diagnosis of Helicobacter pylori Infection and Antibiotic Resistance.

Helicobacter pylori is a major human pathogen that infects approximately half of the global population and is becoming a serious health threat due to its increasing antibiotic resistance. It is the causative agent of chronic active gastritis, peptic ulcer disease, and gastric cancer and has been classified as a Group I Carcinogen by the International Agency for Research on Cancer. Therefore, the rapid and accurate diagnosis of H. pylori and the determination of its antibiotic resistance are important for the efficient eradication of this bacterial pathogen. Currently, H. pylori diagnosis methods mainly include the urea breath test (UBT), the antigen test, the serum antibody test, gastroscopy, the rapid urease test (RUT), and bacterial culture. Among them, the first three detection methods are noninvasive, meaning they are easy tests to conduct. However, bacteria cannot be retrieved through these techniques; thus, drug resistance testing cannot be performed. The last three are invasive examinations, but they are costly, require high skills, and have the potential to cause damage to patients. Therefore, a noninvasive, rapid, and simultaneous method for H. pylori detection and drug resistance testing is very important for efficiently eradicating H. pylori in clinical practice. This protocol aims to present a specific procedure involving the string test in combination with quantitative polymerase chain reaction (qPCR) for the rapid detection of H. pylori infection and antibiotic resistance. Unlike bacterial cultures, this method allows for easy, rapid, noninvasive diagnosis of H. pylori infection status and drug resistance. Specifically, we used qPCR to detect rea for H. pylori infection and mutations in the 23S rRNA and gyrA genes, which encode resistance against clarithromycin and levofloxacin, respectively. Compared to routinely used culturing techniques, this protocol provides a noninvasive, low-cost, and time-saving technique to detect H. pylori infection and determine its antibiotic resistance using qPCR.

Rapid discrimination of Shigella spp. and Escherichia coli via label-free surface enhanced Raman spectroscopy coupled with machine learning algorithms.

Shigella and enterotoxigenic Escherichia coli (ETEC) are major bacterial pathogens of diarrheal disease that is the second leading cause of childhood mortality globally. Currently, it is well known that Shigella spp., and E. coli are very closely related with many common characteristics. Evolutionarily speaking, Shigella spp., are positioned within the phylogenetic tree of E. coli. Therefore, discrimination of Shigella spp., from E. coli is very difficult. Many methods have been developed with the aim of differentiating the two species, which include but not limited to biochemical tests, nucleic acids amplification, and mass spectrometry, etc. However, these methods suffer from high false positive rates and complicated operation procedures, which requires the development of novel methods for accurate and rapid identification of Shigella spp., and E. coli. As a low-cost and non-invasive method, surface enhanced Raman spectroscopy (SERS) is currently under intensive study for its diagnostic potential in bacterial pathogens, which is worthy of further investigation for its application in bacterial discrimination. In this study, we focused on clinically isolated E. coli strains and Shigella species (spp.), that is, S. dysenteriae, S. boydii, S. flexneri, and S. sonnei, based on which SERS spectra were generated and characteristic peaks for Shigella spp., and E. coli were identified, revealing unique molecular components in the two bacterial groups. Further comparative analysis of machine learning algorithms showed that, the Convolutional Neural Network (CNN) achieved the best performance and robustness in bacterial discrimination capacity when compared with Random Forest (RF) and Support Vector Machine (SVM) algorithms. Taken together, this study confirmed that SERS paired with machine learning could achieve high accuracy in discriminating Shigella spp., from E. coli, which facilitated its application potential for diarrheal prevention and control in clinical settings. Graphical abstract.

Myocutaneous sliding flap for reconstruction of divided eyelid nevus.

OBJECTIVE: To evaluate the myocutaneous sliding flap for restructuring the eyelid of divided nevus, thus optimizing the aesthetic outcome. DESIGN: A retrospective clinical study. PARTICIPANTS: Clinical data from patients with a small or medium-sized divided nevus of the eyelids between January 2015 and December 2018 in the Shanghai Ninth People's Hospital were reviewed. METHODS: The safety and efficacy of a surgical approach using a myocutaneous sliding flap were evaluated based on postoperative features and complications. RESULTS: This study included 53 patients with an average age was 21.6 years (range, 2-68 years). The lesions involved the inner canthus in 5 patients (9.43%) and the lateral canthus in 14 patients (26.42%). Three (5.66%) patients had undergone primary surgery elsewhere. Overall, the eyelid margins were in good shape postoperatively at an average follow-up of 22.7 months, and there were no obvious eyelid deformities, lagophthalmos, or other unacceptable complications postoperatively. The nevi were benign intradermal (60.38%), junctional (16.98%), and compound types (22.64%) without malignant transformation, as confirmed by pathologic examination. No malignant transformation was observed until the end of the follow-up period. CONCLUSION: A myocutaneous sliding flap can provide an appropriately size pedicle graft and achieve satisfactory cosmetic results for divided eyelid nevus.

Orbital Reconstruction in Le Fort III Fractures.

BACKGROUND: Few quantitative results are reported about the surgical effect of orbital reconstruction in Le Fort III fractures. The authors' team proposed an ordered surgery method which was effective for Le Fort III fractures. The aim of this study was to evaluate the effectiveness of this method with quantitative outcomes. METHODS: A retrospective study was conducted of all patients who were diagnosed with Le Fort III fractures and underwent orbital and facial fractures repair from January 2015 to June 2019. Surgical reconstruction was performed with an ordered surgery method. Orbital volumes were used to evaluate the effectiveness of orbital reconstruction. RESULTS: Fifteen patients (21 eyes) with Le Fort III fractures were included in this study. Preoperative and postoperative orbital volume changes were statistically significant ( P <0.01). For unilateral fractures, orbital volumes were different in 2 eyes ( P <0.01). For bilateral fractures, orbital volumes were almost the same in 2 eyes ( P =0.34). For the affected eye in unilateral fractures group and eyes in bilateral fractures group, after surgery, orbital volume were almost the same ( P =0.35). CONCLUSIONS: This study showed effectiveness and safety of the ordered surgery in the treatment of Le Fort III fractures, which would result in significant decrease in orbital volumes.

Clinical and immunohistochemical analysis of the verrucous and non-verrucous divided nevus of the eyelids.

PURPOSE: Divided nevus with verrucous hyperplasia will always recur after surgery but non-verrucous divided eyelid nevus rarely recur. This study analyzed the differential expression of Ki-67, S100, Melan A and HMB45 and identified the correlation between the clinical and histopathological features of verrucous and non-verrucous divided eyelid nevus. METHODS: This study included 29 patients, of whom 8 patients had verrucous divided nevus. Immunohistochemistry labeling was used to assess the expression of Ki-67, S100, Melan A and HMB45 after excision. The difference between verrucous and non-verrucous divided eyelid nevus was analyzed. RESULTS: The patients' ages ranged from 2 to 59 years, with a mean age of 19 years. The lesion size ranged from 1.5 to 2.0 cm in diameter and invaded the eyelid margins and the posterior lamella of the eyelids. Immunohistochemistry labeling showed strong positivity for approximately 98.5% of S100 and positive staining for approximately 27.6% of Ki-67, 72.4% of Melan A and 6.8% of HMB45. However, Ki-67 was significantly upregulated in verrucous divided nevus of the eyelids compared with non-verrucous divided nevus, with approximately 38.8% upregulation in verrucous and 18.3% upregulation in non-verrucous nevus. CONCLUSIONS: This study correlated the clinic-pathologic features of verrucous divided eyelid nevus by means of statistically analyzing the varied clinical features and pathological impressions. The significant over-expression of S100 may be used as an indicator of divided nevus of the eyelids, and the over-expressed Ki-67 may contribute to the recurrence of verrucous divided nevus. High expression of HMB45 and Melan A may represent malignant transformation.

Homoclinic orbits in three-dimensional continuous piecewise linear generalized Michelson systems.

In this paper, we investigate the homoclinic orbits for the three-dimensional continuous piecewise linear generalized Michelson systems via analytical methods and numerical simulation. Based on the Poincaré map and invariant manifold theory, we discuss the existence of homoclinic orbits connecting the saddle-focus equilibrium. Finally, numerical simulations are presented to illustrate our results.

Bioresorbable Implants in Reduction of Paediatric Zygomaticomaxillary Complex Fractures Concurrent With Internal Orbital Reconstruction.

PURPOSE: To evaluate the clinical effectiveness and safety of bioresorbable implants for treating paediatric zygomaticomaxillary complex (ZMC) fractures with concomitant orbital floor defects. METHODS: A retrospective review of paediatric patients who underwent ZMC repair with concomitant orbital floor fractures with bioresorbable implants in Shanghai Ninth People's Hospital from July 2015 to June 2019 was performed. The primary outcome measures included ocular motility, diplopia, enophthalmos, facial deformities, and restricted mouth opening, as well as complication rates. Pre- and post-operative computed tomography scans were obtained for clinical diagnosis and surgical effectiveness. RESULTS: Twenty two children were included in this study. Facial deformities were corrected in all 22 cases by surgical reconstruction postoperatively, and the average relative distance of Portals point-Zygomaxillare and Anteriornasalspine-Zygomaxillare were 1.3 ± 0.6mm ( P = 0.22) and 1.2 ± 0.5mm ( P = 0.19). The eye movement restored to normal in 13 patients. The mean amount of relative enophthalmos was 1.0 ± 0.4 mm ( P = 0.12). 12 cases had complete resolution of diplopia postoperatively at the extremes of the gaze, and 1 case presented persistent diplopia on the down gaze as before, but from level III to level I. Facial numbness was resolved completely in 6 cases, and 2 cases presented with persistent numbness but relieved significantly. The average Hounsfield units of RapidSorb plates and OrbFloor PI were 154 ± 5 and 99 ± 4 respectively on computed tomography image obtained 1 week postoperatively, which showed no obvious difference compared with 0.5 year postoperatively ( P > 0.1). Hounsfield units of implants gradually declined around 1 year postoperatively. Hounsfield units of RapidSorb plates (20 ± 1) were consistent with periorbital tissue during postoperative 2-year follow-up, and Hounsfield units of OrbFloor PI (19 ± 1) were consistent with periorbital tissue during postoperative 1.5-year follow-up. No patients had severe sequelae or implant related complications postoperatively. None of bone nonunion, malunion, infection or rejection occurred during the follow-up periods. CONCLUSIONS: Open reduction and internal fixation for the treatment of ZMC fracture have achieved significant improvement in functional and cosmetic outcomes postoperatively. Bioresorbable materials have been proved to be effective and safe in the treatment of children's ZMC and orbital wall fractures.

Comparative evaluation of BACTEC FX, BacT/ALERT 3D, and BacT/ALERT VIRTUO automated blood culture systems using simulated blood cultures.

BACKGROUND: To evaluate the performance of BACTEC FX, BacT/ALERT 3D, and VIRTUO systems using simulated blood culture (BC). METHODS: Two experimental designs based on 'with' or 'without' added trough antibiotic concentrations in bottles were implemented. RESULTS: For the experiment A, A shorter time to detection (TTD) was observed for most of organisms (17/22) in VIRTUO system. VIRTUO system was also faster than 3D and FX systems no matter in aerobic and anaerobic bottles. The anaerobic bottles had faster detection than aerobic bottles in 3D system (13.68 h vs 15.36 h, P < 0.001) and VIRTUO system (10.30 h vs 12.46 h, P = 0.001) but not in FX system (P = 0.38). When antibiotics were present, the bacterial recovery rate (RR) of FX, 3D and VIRTUO systems were 64.10% (50/78), 58.97% (46/78) and 43.59% (34/78), respectively (P = 0.027). the bacterial RR of various bottles were as follows: BPA vs. FA vs. SA [84.44%(38/45) vs. 55.56%(25/45) vs. 42.22(19/45), P < 0.001]; BFN vs. FN vs. SN [36.36%(12/33) vs. 63.64%(21/33) vs.45.45%(15/33), P = 0.078]. CONCLUSIONS: The VIRTUO system allowed faster growth detection for most of organisms compared with FX and 3D systems. When antibiotics were present, the bottles containing antibiotic-binding agent showed better bacterial RR, especially in BACTEC Plus Aerobic/F bottles.

Orbital malformation with dysplastic infraorbital artery in neurofibromatosis type 1.

PURPOSE: To report a case with neurofibromatosis type 1 presenting as prominent enophthalmos and abnormal infraorbital artery. CASE DESCRIPTION: A 19-year-old man with a family history of neurofibromatosis presented with prominent right enophthalmos. Computed tomography showed orbital dysplasia and enlarged inferior orbital fissure but no plexiform neurofibroma. Prominent intraoperative hemorrhage originated from several abnormal arteries in the infraorbital region during orbital reconstruction. A tortuous and dysplastic infraorbital artery was verified postoperatively by computed tomography angiography. The bleeding vessels were supposed to be the orbital branches of the dysplastic infraorbital artery. CONCLUSIONS: The orbital malformation and enlargement of inferior orbital fissure probably resulted in an abnormal infraorbital artery. Selective artery embolization may be chosen as a preceding treatment before orbital reconstruction surgery.

A custom-made conformer wrapped in lower oral mucosa for the correction of severely contracted socket.

PURPOSE: To investigate the clinical effects of a custom-made conformer wrapped in lower oral mucosa for the correction of severely contracted socket. METHODS: Clinical data and photographs of 32 patients with severely contracted socket were retrospectively analyzed. Among the 32 cases, 21 were males and 11 were females. Their ages ranged from 20 to 71 years (mean, 45 years). Each patient underwent conjunctival sac plasty using a custom-made conformer wrapped by oral mucosa, then compression bandage for 1 month. All patients received tarsorrhaphy 6 months postoperatively, and an artificial eye was worn 1 week later. RESULTS: All the grafts were fully vascularized. The conjunctival sacs had enough space to fit the desirable artificial eyes, and adequate aesthetic outcomes were reached postoperatively. The mean depth of the upper fornix was 4.28 ± 0.66 mm preoperatively and 18.84 ± 0.65 mm postoperatively (p < 0.01), and lower fornix depth was 2.69 ± 0.42 and 8.78 ± 0.82 mm, respectively (p < 0.01). Lower lip deformity occurred in one case. CONCLUSION: A custom-made conformer wrapped in lower oral mucosa was a safe and effective grafting material. The grafts can be effectively used in the reconstruction of severely contracted socket and lead to good cosmetic outcomes.

Delayed Orbital Apex Syndrome in the Post-Reconstructed Orbit.

Delayed orbital apex syndrome (OAS) is rare during orbital blowout fracture reconstruction. A 30-year-old woman fractured the right orbital floor in a fall and undergone repairing operation 2 weeks later. After severe sneezing on postoperative day 10, she gradually arose vision loss, ophthalmoplegia, ptosis with a dilated and fixed pupil within few hours, then consulted our department and was diagnosed as OAS. Computed tomography scan showed displaced implant and retrobulbar emphysema resulting in a constellation of compression to orbital apex. Therefore, an exploratory operation was engaged to reposition the implant and reduce the emphysema concurrent with mega-dose steroids. The patient regained vision immediately and resolved all symptoms at the 6 months follow-up.

Removal of Orbital Metallic Foreign Bodies With Image-Guided Surgical Navigation.

PURPOSE: To describe the use of an image-guided 3-dimensional surgical navigation system for the removal of metallic foreign bodies from the human intraorbital region. PATIENTS AND METHODS: Between January 2016 and June 2019, 30 patients with metallic foreign bodies in the orbital area underwent image-guided 3-dimensional surgical navigational removal at the authors' center, and their data were retrospectively analyzed. Patients' age, gender, complaints, cause of initial injury, location, interval between injury, and surgery were recorded. Preoperative CT scans of the orbits were obtained and used for preoperative planning. The 3-dimensional navigation system was used for intraoperative navigation. RESULTS: In all 30 patients, the foreign bodies were removed by minimally invasive access without any severe complications. The intraoperative average depth of foreign bodies was 19.98 ± 11.47 mm which was consistent with the depth measured in preoperative planning. The mean length, width, and height of foreign bodies determined in preoperative planning were confirmed by postoperative measurements. There was no significant difference between preoperative and postoperative mean logarithm of Mininal Angle Resolution (logMAR) best-corrected visual acuity. According to the postoperative CT scan, all 30 patients' metallic foreign bodies were successfully removed by surgeries using the surgical navigation system. Most patients who presented with diplopia, eye movement pain, and paresthesia were improved after surgery. CONCLUSION: This study demonstrated that computer-assisted image-guided 3-dimensional surgical navigation had the advantages of accurate real-time localization of foreign bodies, minimizing collateral damage, determining the appropriate surgical path, and increasing the successful rate of foreign body retrieval.

The Effects of Intraoperative Tarsorrhaphy on Conjunctival Chemosis During Orbital Fracture Repair Surgery.

PURPOSE: We employed intraoperative tarsorrhaphy depending on the degree of edema to treat moderate conjunctival chemosis during orbital fracture repair surgery. METHODS: This is a retrospective case review of 1367 patients (1384 eyes) who underwent orbital fracture repair surgery by a transconjunctival approach. All cases of moderate conjunctival chemosis during surgery were included and were divided into 2 groups. In one group, intraoperative tarsorrhaphy was performed immediately the chemosis reached a moderate degree and the conjunctiva was incarcerated by the lower eyelid margin; once severe chemosis developed, stitches were added to cover all of the prolapsed conjunctiva with a palpebral margin. In the second group, moderate chemosis was treated with bandage pressure without stitches even after appearance of severe chemosis. The time course of conjunctival edema was recorded. RESULTS: The incidence of moderate conjunctival chemosis in orbital reconstruction surgery by the transconjunctival approach was 9.4%. The average time for resolution of moderate chemosis in the tarsorrhaphy group (3.5 ±â€Š1.4 days) was obviously shorter than in the bandage group (6.2 ±â€Š1.9 days). The incidence of severe chemosis in the intraoperative tarsorrhaphy group (14.1%) was significantly lower than in the bandage group (31.8%). Overall, the total duration of severe chemosis in the tarsorrhaphy group was obviously shorter than that of the bandage group. CONCLUSION: Intraoperative tarsorrhaphy was a highly effective method of treating moderate chemosis and preventing severe conjunctival chemosis during orbital fracture repair surgery.

Prevalence of healthcare-associated infections and antimicrobial use in China: Results from the 2018 point prevalence survey in 189 hospitals in Guangdong Province.

BACKGROUND: Limited data on healthcare-associated infections (HAIs) are available from the developing world, thus a point prevalence survey was conducted to determine the prevalence of HAIs and antimicrobial use in Guangdong Province, China. METHODS: A standardized methodology for point prevalence surveys on HAIs and antimicrobial use has been developed by the Chinese Nosocomial Infection Control and Quality Improvement Center. The prevalence of HAIs, antimicrobial use, and baseline hospital-level variables were collected in 189 hospitals from June 2017 to May 2018. RESULTS: Of 5 868 147 patients, 72 976 had one or more HAIs (1.24%), with 82 700 distinct HAIs. The prevalence rates of device-associated infections, including ventilator-associated pneumonia, catheter-associated urinary tract infection, and central line-associated bloodstream infection were 7.92, 2.06, and 0.63 per 1000 catheter-days, respectively. A total of 10 591 (0.18%) HAIs caused by multidrug-resistant organisms were identified. Carbapenem non-susceptibility rates were highest in Acinetobacter species (53.86%) and Pseudomonas aeruginosa (21.60%). Forty-six percent (2 712 258/5 868 147) of inpatients were receiving at least one antimicrobial during this survey. CONCLUSIONS: This survey indicated the relatively lower prevalence of HAIs but higher antimicrobial using in Guangdong Province compared with other mid to low-income and high-income countries. Further studies are warranted to elucidate which HAI-related indicators are the best measures of HAI performance and thus allow improvements leading to better patient outcomes.

Bioresorbable Material in Secondary Orbital Reconstruction Surgery.

PURPOSE: To validate the potential of bioresorbable implantation in secondary revisional reconstruction after inadequate primary orbital fracture repair, with assessment of pre- and postoperative clinical characteristics and computed tomography image findings. METHODS: A retrospective chart review was conducted on 16 consecutive patients treated for orbital fractures at Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, with inadequate prior surgeries between July 2010 and June 2017; patients who had suffered orbital blowout fractures had undergone primary surgeries elsewhere. Secondary repair of orbital fractures used bioresorbable material following unsatisfactory primary orbital repair. Patients' demographics, degree of enophthalmos, ocular motility, diplopia test results, primary implants, and surgical complications were reviewed. RESULTS: All 16 patients had primary orbital implants consisting of Medpor, titanium mesh, hydroxyapatite, or poly-L-lactide. Of the 16 cases, 14 had malpositioned implants posteriorly and two had implant infections. Findings following primary surgery included enophthalmos (12/16), diplopia (9/16), intraorbital abscess (2/16), and ocular movement pain (1/16). Mean preoperative enophthalmos was 3.8 ± 0.8 mm. Secondary reconstruction resulted in a mean reduction of enophthalmos by 3.1 ± 0.9 mm (P < 0.01). Nine in ten patients experienced improvements in postoperative ocular motility and diplopia following secondary surgery. Intraorbital abscesses and eyeball movement-associated pain were cured. CONCLUSIONS: This study demonstrates that secondary orbital reconstruction of previously repaired orbital fractures using bioresorbable material can achieve excellent functional and aesthetic results with minimal complications. Bioresorbable material should be considered in secondary orbital reconstruction when clinically indicated.