Study of the Effect of Bacterial Resistance Monitoring in Clinical Microbiology Testing

Objective:To observe and analyze the effect of bacterial resistance monitoring in clinical microbiology testing.Methods:600 microbial specimens collected in our hospital in the past year(April 2021 to April 2022)were used as the test subjects of this study.The specimens were divided into Group A(control group)and Group B(research group),with 300 cases in each group.Group A consisted of blood culture specimens,while Group B consisted of sputum specimens.After the tests were completed,the rates of unfavorable and favorable results,bacterial species distribution,and bacterial drug resistance of the specimens in both groups were compared.Results:Among group A specimens,29 cases were positive(9.67%)and 271 cases were negative(90.33%);among group B specimens,99 cases were positive(33.00%)and 201 cases were negative(66.00%);the difference between the two groups of data was statistically significant(P<0.05).As for the distribution of the types of bacteria,there were 472 cases of Gram-negative bacteria and 128 cases of Gram-positive bacteria.Conclusion:Bacterial resistance monitoring is helpful in clinical microbiology testing.Through proper monitoring,bacterial resistance can be well understood.In this way,patients get to receive appropriate treatment measures and suitable antibacterial prescriptions,thereby improving the patient outcome.

Risk Factors of Bacterial Resistance to Antibiotics in Internal Medicine and Hemodialysis Nephrology Services at the Edith Lucie Bongo Ondimba General Hospital

Introduction: Antibiotic resistance is a public health problem. It is due to multi-resistant bacteria (MRB). The objective of this study was to determine bacterial resistance to antibiotics in chronic renal failure at the Edith Lucie BONGO ONDIMBA general hospital (HGELBO). Patients, material and method: This was an analytical cross-sectional study conducted from January 1 to August 31, 2019 at the HGELBO. It concerned all patients admitted to the HGELBO with positive bacteriological samples. After a study of the sensitivity to isolated species, the patients were divided into two (02) groups: those MRB positive (+) and not MRB or negative (-). Epi Info software version 3.5.1 was used for the calculation of the rates and the comparison of the variables. The adjusted odds ratio (ORa) with a 95% confidence interval was used to measure the specific effect of each risk factor such as chronic kidney disease and diabetes, in order to rule out confounding factors. Multivariate analysis by binomial logistic regression was used. Results: There were 375 bacteriological samples from 258 patients, among them 247 patients with 235 positive samples or 63%. The eleven (11) are healthy patients. The median age was 33 with extremes ranging from 16 to 90. The female sex was predominant with a sex ratio of 0.6. The majority of MRB+ cases were found in internal medicine and nephrology with 12 cases (38.7%) and hemodialysis with 4 cases (12.9%). Urinary samples were in the majority with 74.5%. Escherichia coli was predominant in 30.3%. After studying the sensitivity to antibiotics of the 247 species included, 113 were MRB+ and 134 BMR- i.e. a frequency of 45.7%. Methicilin-resistant Staphylococcus aureus (MRSA) was predominant (51.3%). Multivariate logistic regression analysis showed that the main risk factor was antibiotic use (0Ra: 3.2 [1.9 - 5.4];p-value < 0.01). Chronic renal failure and diabetes were not risk factors for carriage. The other risk factors identified were: hospitalization of more than 7 days (prolonged), S. aureus infection and male sex. Conclusion: Probabilistic antibiotic therapy leads to the selection of BMRs. Long hospital stays, male sex, and MRSA are risk factors or determinants of antibiotic resistance, but not chronic kidney disease.

Self-adhesive lubricated coating for enhanced bacterial resistance

Limited surface lubrication and bacterial biofilm formation pose great challenges to biomedical implants.Although hydrophilic lubricated coatings and bacterial resistance coatings have been reported,the harsh and tedious synthesis greatly compromises their application,and more importantly,the bacterial resistance property has seldom been investigated in combination with the lubrication property.In this study,bioinspired by the performances of mussel and articular cartilage,we successfully synthesized self-adhesive lubricated coating and simultaneously achieved optimal lubrication and bacterial resistance properties.Additionally,we reported the mechanism of bacterial resistance on the nanoscale by studying the adhesion interactions between biomimetic coating and hydrophilic/hydrophobic tip or living bacteria via atomic force microscopy.In summary,the self-adhesive lubricated coating can effectively enhance lubrication and bacterial resistance performances based on hydration lubrication and hydration repulsion,and represent a universal and facial strategy for surface functionalization of biomedical implants.

Improving the resistance of the rice PTGMS line Feng39S by pyramiding blast,bacterial blight,and brown planthopper resistance genes

Knowledge of rice(Oryza sativa L.)genes and various DNA markers can be used in genomic breeding programs aimed at developing improved elite rice cultivars.We used an efficient genomic breeding approach to pyramid four resistance genes(Pi2,Xa23,Bph14,and Bph15)in the popular photoperiod-and thermosensitive genic male sterile(PTGMS)rice line Feng39S.We performed foreground selection for the target genes,followed by recombinant selection and background selection.This process reduced the sizes of the genomic segments harboring the target genes(566.8 kb for Pi2,1143.9 kb for Xa23,774.7 kb for Bph14,and 1574.9 kb for Bph15)and accelerated the recovery of the recurrent parent genome to proportions ranging from 98.77%to 99.16%,thus resulting in four near-isogenic lines.To assemble the four resistance genes in Feng39S,we performed a double-way cross combined with foreground and background selection to generate two improved lines of Feng39S(Pi2+Xa23+Bph14+Bph15)with a recurrent parent genome recovery of 98.98%.The two lines showed agronomic performance,grain quality,and fertility–sterility transition characteristics similar to those of the original Feng39S line.The newly developed PTGMS lines and corresponding hybrid combinations were resistant to various field blast isolates and seven representative isolates of bacterial blight.At the seedling stage,the lines also showed resistance against brown planthopper.This study provides an efficient and accurate genomic breeding approach for introducing desirable traits into PTGMS lines.

Six-year analysis of key monitoring for bacterial strain distribution and antibiotic sensitivity in a hospital

BACKGROUND With the widespread use of antimicrobial drugs,bacterial resistance has become a significant problem,posing a serious threat to public health.The prevalence of clinical infection strains in hospitals and their drug sensitivities are key to the appropriate use of antibiotics in clinical practice.AIM To identify prevalent bacteria and their antibiotic resistance profiles in a hospital setting,thereby guiding effective antibiotic usage by clinicians.METHODS Specimens from across the institution were collected by the microbiology laboratory.The VITEK 2 compact fully automatic analyzer was used for bacterial identification and antibiotic sensitivity testing,and the WHONET5.6 software was utilized for statistical analysis.RESULTS A total of 12062 bacterial strains of key monitoring significance were detected.Staphylococcus aureus demonstrated widespread resistance to penicillin,but none of the strains were resistant to vancomycin or linezolid.Moreover,219 strains of methicillin-resistant coagulase-negative staphylococci and 110 strains of methicillin-resistant Staphylococcus aureus were detected.Enterococcus faecalis showed moderate resistance to the third-generation quinolones ciprofloxacin and levofloxacin,but its resistance to nitrofurantoin and tetracycline was low.Enterococcus faecium displayed significantly lower resistance to third-and fourthgeneration quinolones than Enterococcus faecalis.The resistance of two key monitoring strains,Escherichia coli and Klebsiella pneumoniae,to piperacillin/tazobactam was 5%-8%.However,none of the Escherichia coli and Klebsiella pneumoniae strains were resistant to meropenem.The resistance of Acinetobacter baumannii to piperacillin/sulbactam was nearly 90%.Nonetheless,the resistance to tigecycline was low,and Pseudomonas aeruginosa demonstrated minimal resistance in the antibiotic sensitivity test,maintaining a resistance of<10%to the cephalosporin antibiotics cefotetan and cefoperazone over the last 6 years.The resistance to amikacin remained at 0.2%over the past 3 years.CONCLUSION Our hospital’s overall antibiotic resistance rate was relatively stable from 2017 to 2022.The detection rates of key monitoring strains are reported quarterly and their resistance dynamics are monitored and communicated to the entire hospital,which can guide clinical antibiotic selection.

ZnO Incorporated Acrylamide Grafted Chitosan Based Composite Film for Advanced Wound Healing Applications

This study was carried out to prepare ZnO nanoparticles incorporated acrylamide grafted chitosan composite film for possible biomedical application especially drug loading in wound healing. ZnO nanoparticles were prepared by co-precipitation method from zinc acetate di-hydrate and incorporated in acrylamide grafted chitosan. FT-IR and TGA of the prepared composite film confirmed the successful incorporation of ZnO nanoparticles in the acrylamide-grafted polymer matrix. SEM images showed that the ZnO nanoparticles were homogeneously distributed on the porous matrix of the composite film. Water uptake and buffer uptake analysis revealed that the composite film could hold water and buffer sufficiently, which facilitated the absorption of exudate from the wound site. Amoxicillin was loaded in the prepared composite film and the maximum loading efficiency was found to be 67.33% with drug concentration of 300 ppm. In vitro studies showed greater antimicrobial activity of drug-loaded composite film compared to both pure film and standard antibiotic disc. Finally, the In vivo mouse model showed maximum healing efficiency compared to conventional gauge bandages because the loading of antibiotic in the film produced a synergistic effect and healing time was reduced.

Analysis of the Tropism and Anti-Bacterial Potential of a Type of Clay

Natural clays have been used by man in infections of bacterial etiology, since the first historical registers. Our attention turned to a red-colored clay, known in the northeast of Brazil as “barro de lou&#231a” (dish clay). These clays and other natural earth materials seem interesting to us, as the blockage of the liberation of toxins or inactivation, may be related to the interruption of infection cycles in the skin and mucous membranes. The adsorptive and absorptive properties of the mineral clays are well documented in the cure process of skin and gastrointestinal diseases. Susceptibility and bacterial tropism tests were carried out. The results were analyzed and interpreted according to the conventional microbiological protocol. The bacterial strains, Staphylococcus aureus, Escherichia coli e Pseudomonas aeruginosa, did not present a susceptibility profile to an isotonic solution of clay, but there was an increase of the bacterial tropism as the concentration of the isotonic solution was increased, being the minimal observed concentration of 100 mg/mL. Our aim is to document a type of red clay from the northeast of Brazil with possible attraction properties (Tropism) to bacteria and their toxins.

Prevalence of Extended-Spectrum Beta-Lactamase-Producing Strains Isolated at Zinder National Hospital (ZNH) in 2021 and Their Antibiotic Susceptibility Profile

Purpose: Bacterial resistance to antibiotics has become a global public health problem. Enterobacteriaceae ESBL is among the most incriminated in this emergence which reduces the therapeutic possibilities. Thus, the objective of this study is to determine the prevalence of the extended-spectrum beta- lactamase (ESBL) producing Enterobacteriaceae at ZNH and their antibiotic susceptibility profile. Materials and Methods: This is a prospective study carried out over 5 months in all hospitalized and non-hospitalized patients in whom a culture was taken for the diagnosis of an infection. The search for ESBL is done by the double disc diffusion method. Results: In total, 21 out of 45 of our strains are ESBL-producing, i.e. a frequency of 46.7%. The mean age is 41.62 (±22.90) with extremes of 2.6 - 78 years. The distribution of ESBL producing species showed a predominance of E. coli with 66.7% followed by K. pneumoniae and K. oxytoca each 9.5%. All ESBL strains were resistant to Amoxicillin, Cefalotin, Pipiracillin, Piperacillin + tazobactam, Ticarcillin, Ticarcillin + clavulanic acid. Resistance to C3G and Aztreonam was each 95.5%, to Amoxicillin/clavulanic acid 9.1%. All strains were sensitive to imipenem. E. coli strains showed resistance: 85.7% to ciprofloxacin, 50% to Amikacin, 57.1% to Gentamicin. For K. pneumoniae, it is 66.7% for Gentamicin and Ciprofloxacin. Conclusion: Our study reports a high prevalence of ESBL at the HNZ. This must be taken into account in order to monitor this phenomenon which constitutes a public health problem. The study also reports sensitivity to Amoxicillin/clavulanic acid and Aminoside which can be an alternative.

Causative bacteria of ventilator-associated pneumonia in intensive care unit in Bahrain:Prevalence and antibiotics susceptibility pattern

BACKGROUND Ventilator-associated pneumonia(VAP)is defined as pneumonia that occurs two calendar days following endotracheal intubation or after that.It is the most common infection encountered among intubated patients.VAP incidence showed wide variability between countries.AIM To define the VAP incidence in the intensive care unit(ICU)in the central gove-rnment hospital in Bahrain and review the risk factors and the predominant bacterial pathogens with their antimicrobial susceptibility pattern.METHODS The research was a prospective cross-sectional observational study over six months from November 2019 to June 2020.It included adult and adolescent patients(>14 years old)admitted to the ICU and required intubation and mechanical ventilation.VAP was diagnosed when it occurred after 48 h after endotracheal intubation using the clinical pulmonary infection score,which considers the clinical,laboratory,microbiological,and radiographic evidence.RESULTS The total number of adult patients admitted to the ICU who required intubation and mechanical ventilation during the study period was 155.Forty-six patients developed VAP during their ICU stay(29.7%).The calculated VAP rate was 22.14 events per 1000 ventilator days during the study period,with a mean age of 52 years±20.Most VAP cases had late-onset VAP with a mean number of ICU days before the development of VAP of 9.96±6.55.Gram-negative contributed to most VAP cases in our unit,with multidrug-resistant Acinetobacter being the most identified pathogen.CONCLUSION The reported VAP rate in our ICU was relatively high compared to the international benchmark,which should trigger a vital action plan for reinforcing the implementation of the VAP prevention bundle.

Current State and Development of Quaternary Ammonium Compounds Disinfectants in China

Quaternary ammonium compound are a class of broad-spectrum,high-efficiency and low-toxicity bactericide,which are widely used in daily life and industrial sterilization.Herein,the current state of domestic quaternary ammonium disinfectant products was summarized,as well as those new products developed and studied,and the development trend was also predicted.

Typhoid intestinal perforation in developing countries: Still unavoidable deaths?

Typhoid fever is a public health challenge mostly concentrated in impoverished, overcrowded areas of the developing world, with lack of safe drinking and sanitation. The most serious complication is typhoid intestinal perforation(TIP), observed in 0.8% to 39%, with a striking rate difference between high-income and low-middle-income countries. Although the mortality rate consequent to TIP in resource-poor countries is improved in the last decades, it is still fluctuating from 5% to 80%, due to surgical-and not surgical-related constraints. Huge economic costs and long timelines are required to provide a short-to middle-term solution to the lack of safe water and sanitation. Inherent limitations of the currently available diagnostic tools may lead to under-evaluation as well as over-evaluation of the disease, with consequent delayed treatment or inappropriate, excessive antibiotic use, hence increasing the likelihood of bacterial resistance. There is a need for immunization programs in populations at greatest risk, especially in sub-Saharan Africa. Uniform surgical strategies and guidelines, on the basis of sound or prospective surgical studies and adapted to the local realities, are still lacking. Major drawbacks of the surgical treatment are the frequent delays to surgery, either for late diagnosis or for difficult transports, and the unavailable appropriate intensive care units in most peripheral facilities. As a consequence, poor patient's conditions at presentation, severe peritoneal contamination and unsuitable postoperative care are the foremost determinant of surgical morbidity and mortality.

Multi Drug Resistant <i>Escherichia coli</i>Superinfection in Patient with COVID-19

Background: Coronavirus Disease 2019 (COVID-19) has infected millions people worldwide and is continuing to spread rapidly. Patients with COVID-19 may be superinfected with other microorganisms. The prevalence of bacterial superinfection among coronavirus patients is not well understood. Aim: The aim of presenting this case is to highlight the problem of Multi-Drug Resistant (MDR) bacterial infection in COVID-19 patients. Case Presentation: Here we reported a 46 years old patient with the previous history of Escherichia coli urinary tract infection. A few weeks later, the patient was recovered from COVID-19 infection and was treated with antiviral therapy until PCR results become negative. Meanwhile, the patients developed urinary tract infection with MDR Escherichia coli even resistant to imipenem and required a critical treatment. Conclusion: Our finding suggests that greater attention should be paid to coronavirus infection complications and prophylaxis use of antibiotics. In addition, more studies are required to better understand the risk factors which are responsible for the superinfection and emergence of drug-resistant strains during COVID-19 infection.

Antibiotic residues in milk and milk products:A momentous challenge for the pharmaceutical industry and medicine

Dairy products are nutritious food items that contain various essential nutrients,however,it has been proven that residual antibiotics have contaminated such products.These residues can cause several side effects on human health.They increase antimicrobial resistance against several threatening microorganisms,as well as significant growth in allergenic reactions.Various methods,including heat treatments,have been applied to alleviate and reduce the effect of antibiotic residue level in milk and milk products.Changes in drug levels were not sig-nificantly remarkable,obliging researchers to find new approaches to prevent or reduce their risk and limit their complications on human health.

A new track for antibacterial treatment:Progress and challenges of using cytomembrane-based vesicles to combat bacteria

The emergence and re-emergence of antibiotic-resistant bacteria,especially superbugs,are leading to complicated infections that are increasingly difficult to treat.Therefore,novel alternative antimicrobial therapies are urgently needed to reduce the morbidity and mortality caused by antibiotic resistance.The development of biomimetic-based therapy is expected to provide innovative means for addressing this challenging task.As a kind of novel biomaterial,cytomembrane-based vesicles(MVs)continue to receive considerable attention in antimicrobial therapy owing to their inherent biocompatibility,design flexi-bility,and remarkable ability to interact with biological molecules or the surrounding environment.These remarkable cell-like properties and their inherent interaction with pathogens,toxins,and the immune system underlie MVs-based functional protein therapy and targeted delivery to develop advanced therapeutic strategies against bacterial infection.This review provides a fundamental under-standing of the characteristics and physiological functions of cytomembrane-based vesicles,focusing on their potential to combat bacterial infections,including detoxification,immune modulation,antibiotics delivery,and physical therapy.In addition,the future possibilities and remaining challenges for clinically implementing MVs in the field of antibacterial treatment are discussed.

Development Problems and Countermeasures of Detergents

At present,there are many problems in detergents,such as environmental pollution and bacterial resistance,which have puzzled many researchers.This article aimed to review the development of detergent problems,and try to point out the countermeasures to deal with these problems.These strategies include formulate the green development policy of detergents and improve the practicability of the policy,strengthening the awareness of the standard use of detergent,enhancing the publicity,establishing and improving the enterprise safety standard system of detergent products,strengthening and improving the monitoring system of detergent waste water,intensifying the research and development of new safe and green non-toxic detergent,researching and developing pure Chinese medicine enzyme detergent,researching and developing completely herbal compound enzyme detergent.

The role of bacterial signaling networks in antibiotics response and resistance regulation

Excessive use of antibiotics poses a threat to public health and the environment.In ecosystems,such as the marine environment,antibiotic contamination has led to an increase in bacterial resistance.Therefore,the study of bacterial response to antibiotics and the regulation of resistance formation have become an important research field.Traditionally,the processes related to antibiotic responses and resistance regulation have mainly included the activation of efflux pumps,mutation of antibiotic targets,production of biofilms,and production of inactivated or passivation enzymes.In recent years,studies have shown that bacterial signaling networks can affect antibiotic responses and resistance regulation.Signaling systems mostly alter resistance by regulating biofilms,efflux pumps,and mobile genetic elements.Here we provide an overview of how bacterial intraspecific and interspecific signaling networks affect the response to environmental antibiotics.In doing so,this review provides theoretical support for inhibiting bacterial antibiotic resistance and alleviating health and ecological problems caused by antibiotic contamination.

Identification of molecular markers linked to rice bacterial blight resistance genes from Oryza meyeriana

Y73 is a progeny of asymmetric somatic hybridization between Oryza sativa cv.Dalixiang and the wild rice species Oryza meyeriana.Inoculation with a range of strains of Xanthomonas oryzae pv.oryzae showed that Y73 had inherited a high level of resistance to rice bacterial blight(BB)from its wild parent.An F2 population of 7125 individuals was constructed from the cross between Y73 and a BB-susceptible cultivar IR24.After testing 615 SSR and STS markers covering the 12 rice chromosomes,186 markers were selected that showed polymorphism between Y73 and IR24.Molecular markers linked to the BB resistance genes in Y73 were scanned using the F2 population and the polymorphic markers.The SSR marker RM128 on chromosome 1,the STS marker R03D159 on chromosome 3 and the STS marker R05D104 on chromosome 5 were found to be linked to the rice BB resistance genes in Y73.

Mass spectrometry profiling of single bacterial cells reveals metabolic regulation during antibiotics induced bacterial filamentation

Bacterial antimicrobial resistance(AMR)is a severe threat to global health and development.Under the stimulation of antibiotics,bacterial cells can undergo filamentation and generate daughter cells with stronger AMR.The current research on bacterial AMR mechanism is mainly conducted with a population of cells.However,bacterial cells exhibit heteroresistance,making the study at population level not reliable.Herein,we developed single bacterial cell metabolic profiling by mass spectrometry(MS)to study bacterial AMR at single-cell level.By utilizing a microprobe controlled by a microoperation platform,single filamentous extended spectrum beta-lactamase(ESBL)producing Escherichia coli(ESBL-E.coli)cells generated by ceftriaxone sodium stimulation can be extracted and spray-ionized for MS analysis.Heterogeneous among ESBL-E.coli cells under the same antibiotic stimulus condition was observed from mass spectra as well as cell morphology.The metabolic profiles by MS of different individual cells can be clustered into subgroups well in accordance with bacterial cell length.Metabolic pathways including arginine and proline metabolism,as well as cysteine and methionine metabolism were disclosed to play an important role in the bacterial SOS-associated filamentation against antibiotics.The microprobe electrospray ionization-MS-based single bacterial cell analysis method is promising in the study of various bacterial AMR mechanism and can reveal the heterogeneity of bacterial AMR from-cell-to-cell.

Engineering Janus gold nanorod–titania heterostructures with enhanced photocatalytic antibacterial activity against multidrugresistant bacterial infection

Photocatalytic antibacterial approach shows great potential in treating multidrug-resistant bacterial infections.However,the bactericidal efficiency heavily depends on the photocatalytic activity of semiconductor materials,which is limited by the fast recombination of photogenerated electron–hole pairs.Janus nano-heterostructures with spatial control growth of TiO_(2)nanoparticles(NPs)at one end of gold nanorods(Au NRs)are designed via surface ligand regulation for photocatalytic sterilization and infected wound healing.The asymmetric nanostructure of Janus gold nanorod-titanium dioxide nanoparticles(Janus AuNR-TiO_(2) NPs)promotes the directional migration of charge carriers and is more conducive to the spatial separation of electron–hole pairs.Moreover,the injection of hot electrons and enhancement of plasmon near-fields from the surface plasmon resonance(SPR)effect further improve the photocatalytic efficiency of Janus AuNR-TiO_(2) NPs.Under simulated sunlight irradiation,large amounts of reactive oxygen species(ROS)are generated for photocatalytic antibacterial activity.Enhanced bactericidal efficiency up to 99.99%against methicillin-resistant Staphylococcus aureus(MRSA)is achieved in vitro.Furthermore,Janus AuNR-TiO_(2) NPs exhibit superior biocompatibility,structural stability,and also remarkably accelerate MRSA-infected wound healing.Taking the above all into consideration,Janus AuNR-TiO_(2) NPs,as an efficient antibacterial photocatalyst,offers a promising strategy for MRSA infectious therapy.

Improving mechanical and antibacterial properties of PMMA via polyblend electrospinning with silk fibroin and polyethyleneimine towards dental applications

Poly(methylmethacrylate)(PMMA)is a widely used material in dental applications,particularly as denture resins.Due to thermally unstable and wet oral cavity,the implanted PMMA based resins occasionally deform and grow bacterial biofilms at the interface between oral cavity and the biomaterial.Several strategies attempted earlier to improve the bacterial resistance and mechanical performance of PMMA.Poly(ethyleneimine)(PEI)is a hyperbranched cationic polymer shown earlier to improve antibacterial activity of resins but do not improve mechanical properties of the resins alone,while silk fibroin(SF)is a natural biopolymer with unique material properties.In this study,we combined SF and PEI towards development of antibacterial and mechanically superior PMMA based materials towards overcoming its drawbacks.Using polyblend electrospinning to combine SF,PEI and PMMA,we successfully developed intrinsically antibacterial and mechanically reinforced nanofiber mats.We propose that the resulting nanofiber mats have the potential to be incorporated into PMMA based denture resin materials to overcome the problems of patients and improve their quality of life.