Introduction: Intensive care unit (ICU) patients are at the greatest risk of acquiring nosocomial infections, partly because of their serious underlying disease, but also by exposure to life-saving invasive procedures. Hospital-acquired infections increase patient morbidity, increase the length of hospital stay and hospital costs, and also increases mortality rate. The basic knowledge of organisms infecting ICU patients is very important to empirically select appropriate antibiotics, so that the most likely infecting organisms are addressed. Objective: The aim of the study was to find out the etiologic agents causing infection in medical intensive care unit patients. Results In our study of 289 patients, 180 (62.3%) showed a growth of organism during the stay in ICU. The most common site of infection was the respiratory tract in 138 patients (47.8%) with 60 patients (20.8%) showing Acinetobacter baumannii.
Cross Infection ; Intensive Care Units ; Acinetobacter baumannii ; Respiration, Artificial

Background and Objective: Leptospirosis is a disease caused by pathogenic Leptospira prevalent in tropical countries like the Philippines. Some studies have shown that the role of currently used antibiotics for leptospirosis is unclear since trials have found no significant benefit to patient outcomes compared to placebo. This signals the need for alternative therapies, such as herbal medicines, which may provide effective therapeutic regimens in treating this infection. In this study, we characterized the antibacterial potential of three Philippine herbal medicines against Leptospira interrogans. Methods: Crude methanolic extracts of Momordica charantia, Cassia alata, and Allium sativum were subjected to an optimized broth microdilution assay against L. interrogans, utilizing the resazurin-resorufin reaction as a cell proliferation and viability indicator. Results: The respective minimum inhibitory concentrations of the plants were found to be as follows: 1.25 mg/mL (M. charantia), 2.5 mg/mL (C. alata), and >5 mg/mL (A. sativum). Conclusions Among the three herbal medicines, M. charantia and C. alata proved to have antibacterial activity against L. interrogans. Given the promising potential of two of these plant extracts, exploring the use of other solvents to extract natural compounds from these plants, and discovering possible synergistic effects between these plants and conventional antibiotics may be worthwhile.
Leptospira interrogans ; Herbal Medicine

Iron is an essential element for living organisms that plays critical roles in the process of bacterial growth and metabolism. However, it remains to be elucidated whether piuB encoding iron-uptake factor is involved in iron uptake and pathogenicity of Xanthomonas axonopodis pv. glycines (Xag). To investigate the function of piuB, we firstly generated a piuB deletion mutant (ΔpiuB) by homologous recombination. Compared with the wild-type, the piuB mutant exhibited significantly reduced growth and virulence in host soybean. The mutant displayed markedly increased siderophore secretory volume, and its sensitivity to Fe³⁺, Cu²⁺, Zn²⁺ and Mn²⁺ was significantly enhanced. Additionally, the H₂O₂ resistance, exopolysaccharide yield, biofilm formation, and cell mobility of ΔpiuB were significantly diminished compared to that of the wild-type. The addition of exogenous Fe³⁺ cannot effectively restore the above characteristics of ΔpiuB. However, expressing piuB in trans rescued the properties lost by ΔpiuB to the levels in the wild-type. Taken together, our results demonstrated that PiuB is a potential factor for Xag to assimilate Fe³⁺, and is necessary for Xag to be pathogenic in host soybean.
Iron ; Glycine max ; Virulence ; Xanthomonas axonopodis/genetics* ; Hydrogen Peroxide

Plant bioreactor is a new production platform for expression of recombinant protein, which is one of the cores of molecular farming. In this study, the anti DYKDDDDK (FLAG) antibody was recombinantly expressed in tobacco (Nicotiana benthamiana) and purified. FLAG antibody with high affinity was obtained after immunizing mice for several times and its sequence was determined. Based on this, virus vectors expressing heavy chain (HC) and light chain (LC) inoculated into Nicotiana benthamiana leaves by using Agrobacterium-mediated delivery. Accumulation of the HC and LC was analyzed by SDS/PAGE followed by Western blotting probed with specific antibodies from 2 to 9 days postinfiltration (dpi). Accumulation of the FLAG antibody displayed at 3 dpi, and reached a maximum at 5 dpi. It was estimated that 66 mg of antibody per kilogram of fresh leaves could be obtained. After separation and purification, the antibody was concentrated to 1 mg/mL. The 1:10 000 diluted antibody can probe with 1 ng/mL FLAG fused antigen well, indicating the high affinity of the FLAG antibody produced in plants. In conclusion, the plant bioreactor is able to produce high affinity FLAG antibodies, with the characteristics of simplicity, low cost and highly added value, which contains enormous potential for the rapid and abundant biosynthesis of antibodies.
Animals ; Mice ; Antibodies ; Nicotiana/genetics* ; Agrobacterium/genetics* ; Bioreactors ; Blotting, Western

Objective: To report a case of acute postoperative endophthalmitis following cataract surgery due to Pseudomonas stutzeri in a healthy elderly male. Methods: This is a case report. Results: A non-hypertensive, non-diabetic male in his late 60s consulted due to eye pain and blurred vision 5 days after an uncomplicated extracapsular cataract extraction with posterior chamber intraocular lens implantation (PCIOL) on his left eye. On examination, the visual acuity was light perception. Slit-lamp examination showed ciliary injection, conjunctival congestion, mild corneal edema with Descemet membrane folds, hazy anterior chamber with fibrin and a 2-millimeter hypopyon, and a visible PCIOL. IOP was 10 mmHg with no leak on Seidel’s test, and there was poor view of the fundus. B-scan ultrasonography showed findings consistent with endophthalmitis. He was given topical, intravitreal, and systemic antibiotics, and emergency vitrectomy was done. The vitreous sample culture revealed Pseudomonas stutzeri. Despite aggressive medical and surgical management, vision loss was not prevented. Conclusion Acute postoperative endophthalmitis from Pseudomonas stutzeri is rare; if not recognized and treated promptly, this complication has devastating outcomes. It may present with a fulminant course regardless of the associated risks for infection. Prevention, early recognition, and timely management can prevent unfavorable visual outcomes.
Endophthalmitis ; Pseudomonas stutzeri

BACKGROUND AND OBJECTIVE

Leptospirosis is a disease caused by pathogenic Leptospira prevalent in tropical countries like the Philippines. Some studies have shown that the role of currently used antibiotics for leptospirosis is unclear since trials have found no significant benefit to patient outcomes compared to placebo. This signals the need for alternative therapies, such as herbal medicines, which may provide effective therapeutic regimens in treating this infection. In this study, we characterized the antibacterial potential of three Philippine herbal medicines against Leptospira interrogans.

Crude methanolic extracts of Momordica charantia, Cassia alata, and Allium sativum were subjected to an optimized broth microdilution assay against L. interrogans, utilizing the resazurin-resorufin reaction as a cell proliferation and viability indicator.

The respective minimum inhibitory concentrations of the plants were found to be as follows: 1.25 mg/mL (M. charantia), 2.5 mg/mL (C. alata), and >5 mg/mL (A. sativum).

Among the three herbal medicines, M. charantia and C. alata proved to have antibacterial activity against L. interrogans. Given the promising potential of two of these plant extracts, exploring the use of other solvents to extract natural compounds from these plants, and discovering possible synergistic effects between these plants and conventional antibiotics may be worthwhile.

Pertussis is an acute, highly infectious respiratory disease caused by Bordetella pertussis, and is one of the leading causes of infant disease and death worldwide. The pertussis vaccine has been used in the expanded program on immunization globally since 1974 and the vaccination coverage remains high. In recent years, the pertussis incidence rate increased, even pertussis outbreaks occurred, in more and more countries or areas after years with low incidence level. The disease burden of pertussis has been seriously underestimated, and the prevention and control of pertussis is facing many challenges. This article reviews the epidemic status of pertussis worldwide, the factors affecting the reemergence of pertussis, and the challenges in the prevention and control to provide a reference for prevention and control of pertussis.
Infant ; Humans ; Whooping Cough/prevention & control* ; Vaccination ; Pertussis Vaccine/therapeutic use* ; Bordetella pertussis ; Disease Outbreaks

In this study, a new Bacillus velezensis strain Bv-303 was identified and its biocontrol effect against rice bacterial-blight (BB) disease caused by Xanthomonas oryzae pv. oryzae (Xoo) was investigated. Cell-free supernatant (CFS) of strain Bv-303 under different growth conditions were prepared to test the antagonistic activity and stability against Xoo by the Oxford-cup method in vitro. The antibacterial effect of strain Bv-303 to BB disease in rice were further analyzed in vivo by spraying the cell-culture broth (CCB), CFS and cell-suspension water (CSW), respectively, on the rice leaves inoculated with Xoo. Additionally, rice seeds germination rate and seedling growth under the strain Bv-303 CCB treatment were tested. The results showed that the strain Bv-303 CFS significantly inhibited Xoo growth by 85.7%‒88.0% in vitro, which was also stable under extreme environment conditions such as heat, acid, alkali and ultraviolet light. As tested in vivo, spraying the CCB, CFS or CSW of strain Bv-303 on the Xoo-infected leaves enhanced rice plant resistance to BB disease, with CCB showing the highest increase (62.7%) in disease-resistance. Notably, CCB does not have negative effects on rice seed germination and seedling growth. Therefore, strain Bv-303 has great potential for biocontrol of the rice BB disease.
Oryza ; Fatigue Syndrome, Chronic ; Bacillus ; Xanthomonas ; Plant Diseases/microbiology*

Lysis is a common functional module in synthetic biology and is widely used in genetic circuit design. Lysis could be achieved by inducing expression of lysis cassettes originated from phages. However, detailed characterization of lysis cassettes hasn't been reported yet. Here, we first adopted arabinose- and rhamnose-inducible systems to develop inducible expression of five lysis cassettes (S₁₀₅, A52G, C51S S76C, LKD, LUZ) in Escherichia coli Top10. By measuring OD₆₀₀, we characterized the lysis behavior of strains harboring different lysis cassettes. These strains were harvested at different growth stages, induced with different concentrations of chemical inducers, or contained plasmids with different copy numbers. We found that although all five lysis cassettes could induce bacterial lysis in Top10, lysis behaviors differed a lot at various conditions. We further found that due to the difference in background expression levels between strain Top10 and Pseudomonas aeruginosa PAO1, it was hard to construct inducible lysis systems in strain PAO1. The lysis cassette controlled by rhamnose-inducible system was finally inserted into the chromosome of strain PAO1 to construct lysis strains after careful screen. The results indicated that LUZ and LKD were more effective in strain PAO1 than S₁₀₅, A52G and C51S S76C. At last, we constructed an engineered bacteria Q16 using an optogenetic module BphS and the lysis cassette LUZ. The engineered strain was capable of adhering to target surface and achieving light-induced lysis by tuning the strength of ribosome binding sites (RBSs), showing great potential in surface modification.
Rhamnose/pharmacology* ; Plasmids/genetics* ; Pseudomonas aeruginosa ; Escherichia coli/metabolism*

Experimental model of Pseudomonas aeruginosa biofilm was established in vitro by using biofilm reactor. The aim of this study was evaluating the removal effect of two kinds of water flowing through bactericide resin on Pseudomonas aeruginosa biofilm, and exploring the effectiveness of continuous treatment with low concentration disinfection factor on dental unit waterlines. The experimental group selected 1-2 mg/L iodinated resin (IR) filtered water and bromined hydantoin resin (BHR) filtered water with the control group selecting the sterile distilled water. Biofilms were treated by using the immersion method for 3, 7, 10, 20, and 40 days. Total viable count (TVC) and laser confocal microscopy method (CLSM) were selected to evaluate the biofilm removal effect. The result of TVC showed that in group IR, the bacterial clearance after the treatment of 3, 7, 10, and 20 days was lower than 99.9% and unqualified. The bacterial clearance after the treatment of 40 days was 99.9%,which is qualified. In group BHR, it was lower than 99.9% and unqualified after the treatment of 3, 7, and 10 days. It was and 99.99%, 100.00% after the treatment of 20, 40 days, respectively. The result of CLSM showed that before treatment, Pseudomonas aeruginosa biofilm showed a sheet and mass distribution. The bacterial coverage was 19.24%±1.97%. The proportion of viable bacteria was 93.91%±1.39%, and the biofilm matrix coverage was 17.69%±1.11%. After 20 days of treatment, the biofilm was decreased in the IR group, with the biofilm bacterial coverage reducing to 6.77%±1.61%, the proportion of live bacteria reducing to 54.85%±5.65%, and the biofilm matrix coverage reducing to 2.41%±0.85%.There was significant difference from the pre-treatment and the control (F=359.996,P<0.001). No biofilm-like structure was found in the BHR group. After 40 days of treatment, there was still a small amount of biofilm matrix residue in the IR group, with no bacterial coverage observed. The biofilm matrix coverage was 0.67%±0.47% (F=1 021.373,P<0.001). No biofilm-like structure was found in the BHR group. In conclusion, the continuous application of BHR filter water has more advantages in killing microorganisms in biofilms, removing live and dead bacteria and biofilm matrix in biofilms. Treatment water containing corresponding low concentration disinfection factors can play an important role in the field of biofilm control in dental unit waterlines.
Humans ; Disinfection/methods* ; Pseudomonas aeruginosa ; Biofilms ; Water/pharmacology*