Susceptibility Of Pathogens Research Articles

Modern technologies for studying the genome of mycobacteria

Molecular technologies play a leading role in the laboratory diagnosis of tuberculosis and mycobacteriosis. The successes in studying the genome of Mycobacterium have contributed to significant progress in understanding the evolution, variability, and genetic diversity of pathogens, as well as the development of diagnostic technologies, including research into resistance to anti-tuberculosis drugs.
 The aim of this research is to conduct a comparative study of the spectrum of modern technologies for studying the genomes of mycobacteria and their impact on the efficiency of the laboratory diagnosis of tuberculosis.
 Materials and methods: a search for sources of information was carried out in the PubMed, Medline, Web of Science, and Google Scholar databases. Materials related to the technology of molecular diagnosis of tuberculosis and mycobacteriosis and for determining the susceptibility of pathogens to anti-tuberculosis drugs were selected.
 Results: it was determined that the modern methods for studying the genome of mycobacteria include amplification technologies (PCR analysis), hybridization, restriction, spoligotyping, sequencing, and their various combinations. The main methods are standard and modified protocols of PCR (RAPD-PCR, AP-PCR, rep-PCR, Real-time PCR, Inverse PCR, TB-LAMP, HIP, LM-PCR). Genomic Restriction Analysis can be used in studies of MTBC and NTM strains (RFLP, AFLP analysis, MIRU-VNTR genotyping). The most effective method for genome analysis is WGS. Complex methods that utilize a combination of molecular technologies allow for the direct detection of mycobacteria in clinical samples.
 Conclusions: the widespread application of genomic technologies in the study of mycobacteria will contribute to the effective implementation of the global WHO strategy for the prevention, treatment, and control of tuberculosis and mycobacteriosis

Pathogen susceptibility drives rhizosphere microbiota across mulberry genotypes

Rhizosphere microbial communities differ across plant genotypes, but factors driving assemblages are not very unclear. We hypothesized microbial interactions influence genotype-specific microbiomes, especially when genotypes vary in pathogen susceptibility. Using mulberry (Morus alba L.) trees, we analyzed rhizosphere fungi and bacteria from two genotypes grown in nearly identical conditions, which were the sclerotial disease-resistant JL20 and susceptible JL40. Diagnostics confirmed JL40 susceptibility to fruit rot caused by Ciboria carunculoides. Illumina sequencing revealed Ciboria dominated the JL40 fungal community (39.1% abundance), but was rare in JL20 (0.016%). Overall fungal diversity was lower in JL40. Bacterial communities were compositionally distinct between genotypes despite some shared dominant taxa. Random forest analysis indicated Ciboria enrichment together with other microbes strongly contributed to microbial variation. Our findings demonstrate pathogen susceptibility differences between mulberry genotypes lead to selective enrichment of Ciboria, which correlates with shifts in both fungal and bacterial rhizosphere assemblages.

Nitrofurantoin: properties and potential in treatment of urinary tract infection: a narrative review.

Nitrofurantoin (NF), a wide-spectrum antibiotic accessible since 1953, is utilized widely to treat urinary tract infections as it usually stays active against drug-resistant uropathogen. The use of Nitrofurantoin has increased exponentially since new guidelines have repositioned it as first-line therapy for uncomplicated lower urinary tract infection (UTI). To, although fluoroquinolones are usually used to re-evaluate the first- and second-line therapies for treating uncomplicated UTI, their level of utilization is thought to be inappropriately excessive and will eventually have a detrimental impact; thus, we hypothesize that NF might be the best choice for this condition, because of its low frequency of utilization and its high susceptibility in common UTI pathogens. It can be concluded from this review that NF can be considered as the most effective drug in the treatment of acute urinary infection, but due to the long-term side effects of this drug, especially in elderly patients, it is essential to introduce some criteria for prescribing NF in cases of chronic UTI.

Analysis of Antimicrobial Susceptibility in Bacterial Pathogens Associated with Urinary Tract Infections from Beijing Teaching Hospital in China, 2009-2017.

Since a urinary tract infection (UTI) is easy to relapse and difficult to treat, the antibiotic resistance rate has increased year by year in recent years. This study was to analyze the characteristics of the common pathogenic bacteria and the changes of antibiotic resistance in urinary system infection, so as to guide the standard use of antibiotics in a clinical urinary tract infection and control nosocomial infection effectively. A total of 5,669 strains of a urinary tract infection in the hospital from January 2009 to December 2017 were retrospectively analyzed. Bacterial identification and the antibiotic sensitivity test (AST) were analyzed by using a VITEK-2 Compact system. Of the 5669 pathogens, 3,256 (57.44%) of the strains were Gram-negative bacteria (GNB), 1,474 (26%) were Gram-positive bacteria (GPB), and 939 (16.56%) were fungi. Resistant rates of ESBL-producing strains were all significantly different from non-ESBL-producing strains in Escherichia coli (p < 0.05). The resistance rate of ESBL-producing strains to β-lactam antibiotics was all higher than that of non-ESBL-producing strains in Klebsiella pneumoniae (p < 0.05). The detection rate of vancomycin-resistantEnterococcus faecium and Enterococcus faecalis was 37.3% and 3.1%, respectively, and the detection rate of linezolid-resistantEnterococcus faecium and Enterococcus faecalis was 0.68% and 0%, respectively. The drug resistance rate of candida sp. to fluconazole, itraconazole, and voriconazole was 1.7%, 8.5%, and 3.4%, respectively. No amphotericin B-resistant strains were detected in the research. Among the 5669 strains isolated from urinary tract infection patients, GNB were the main pathogens. Escherichia coli was the major pathogen. The resistance rate of ESBLs-producingEscherichia coli was higher than that of non-ESBLs-producingEscherichia coli in general; meanwhile, β-lactam/β-lactamase inhibitors and carbapenems maintained good antimicrobial activity against Escherichia coli. The resistance rate of non-ESBLs-producingKlebsiella pneumoniae strains was significantly higher than that of ESBLs-producingKlebsiella pneumoniae strains, and drug resistance was more prominent; most of the antibiotic resistance rates were over 50%. The antimicrobial resistance rate of Enterococcus faecium was significantly higher than that of Enterococcus faecalis. There were rare linezolid-resistant strains. The antimicrobial resistance rate of imidazole to fungi was controlled less than 10%.

Propranolol restores susceptibility of XDR Gram-negative pathogens to meropenem and Meropenem combination has been evaluated with either tigecycline or amikacin

BackgroundInfection with extensive-drug-resistant (XDR) carbapenem-resistant (CR) Gram-negative bacteria (GNB) are viewed as a serious threat to human health because of the limited therapeutic options. This imposes the urgent need to find agents that could be used as adjuvants or combined with carbapenems to enhance or restore the susceptibility of XDR CR- GNB. Therefore, this study aimed to examine the effect of propranolol (PR) in combination with Meropenem (MEM) on the susceptibility profile of XDR CR-GNB recovered from severely infected patients as well as to evaluate combining MEM with either tigecycline (TGC) or amikacin (AK).MethodsA total of 59 non-duplicate CR- GNB were investigated for carbapenemase production by the major phenotypic methods. Molecular identification of five major carbapenemase-coding genes was carried out using polymerase chain reactions (PCR). Antimicrobial susceptibility tests were carried out using standard methods. Phenotypic and genotypic relatedness was carried out using the heatmap and ERIC PCR analysis. PR, 0.5 -1 mg/mL against the resulting non-clonal XDR CR-GNB pathogens were evaluated by calculating the MIC decrease factor (MDF). A combination of MEM with either AK or TGC was performed using the checkerboard assay.ResultsA total of 21 (35.6%) and 38 (64.4%) CR-GNB isolates were identified as enterobacterial isolates (including 16 (27.1%) Klebsiella Pneumoniae and 5 (8.5%) Escherichia coli) and non-fermentative bacilli (including, 23 (39%), Acinetobacter baumannii, and 15 (25.4%) Pseudomonas aeruginosa). The heatmap and ERIC PCR analysis resulted in non-clonal 28 XDR CR isolates. PR, at a concentration of 0.5 mg /ml, decreased MICs values of the tested XDR CR isolates (28; 100%) and restored susceptibility of only 4 (14.3%) isolates. However, PR (1 mg/mL) when combined with MEM has completely (28; 100%) restored the susceptibility of the tested XDR CR- GNB to MEM. The MEM + AK and MEM + TGC combination showed mostly additive effects (92.8% and 71.4%, respectively).ConclusionPR at a concentration of 1 mg/mL restored the susceptibility of XDR CR- GNB to MEM which is considered a promising result that should be clinically investigated to reveal its suitability for clinical use in patients suffering from these life-threatening pathogens.

Prevalence of multidrug-resistant Acinetobacter baumannii in endotracheal aspirate samples: Experience at a tertiary hospital

The emergence of resistance to multiple antimicrobial agents in pathogenic bacteria poses a significant public health threat because few or no effective antimicrobials are available for infectious diseases. is a major cause of device-associated infections that pose a serious threat to critically ill patients. Resistance patterns are thought to result in very limited treatment options and high mortality. We examined the prevalence of in endotracheal aspirates samples and explored their antibiotics susceptibility. To determine the value of routine endotracheal aspirate cultures performed prior to the onset of the likely onset of ventilator-associated pneumonia (PVAP) in predicting pathogenic microorganisms and susceptibility to their antibiotics Patients admitted to the ventilatory intensive care unit were tested daily, and endotracheal aspirated (ET) specimens from suspected patients were sent to a microbiology laboratory for culture and sensitivity measurements. Of the 52 patients, only twenty five (48%) developed PVAP. Endotracheal aspirate cultures were positive in all PVAP cases. The most commonly isolated bacteria was 14 (56%), followed by 6 (24%) and 4 (16%). Almost all isolates of are multidrug resistant (MDR). ICU stays greater than 16 days were observed for the pathogen . We believe that multidrug-resistant is a widespread epidemic, leading to high mortality, long ICU stays, and a difficult case for ICU physicians. Further prospective studies are needed to tackle this threat

Sterile body fluids infections: Profile of bacteria and their antimicrobial resistance pattern in a tertiary care hospital from Uttar Pradesh

Objectives: Infections of sterile body fluids are important and significant causes of mortality and morbidity, especially healthcare-associated infections. Species-level identification and antimicrobial resistance profile of bacteria are important determinants while selecting appropriate antimicrobials for empirical and targeted therapy. We conducted this study to observe the distribution of various bacteria and their antimicrobial resistance profile isolated from sterile body fluids. Materials and Methods: We conducted this study in a tertiary care teaching hospital from western Uttar Pradesh for a period of 2 years. All sterile body fluid samples were processed by conventional aerobic bacterial culture followed by their identification up to species level by conventional biochemicals following standard microbiological procedures. The antimicrobial susceptibility of the bacterial pathogens grown in culture was tested by Kirby–Bauer disk diffusion method and interpretation of susceptibility testing was done according to CLSI guidelines 2020. Results: A total of 1980 sterile body fluid samples were collected during the study period and 192 samples were found positive on culture for bacterial pathogens. Gram-negative bacilli (GNB) were predominantly isolated, comprising 83.33% in comparison to 16.67 % of Gram-positive cocci. Among Staphylococcus aureus isolates, 75% were methicillin-resistant S. aureus. All S. aureus isolates were sensitive against vancomycin and linezolid. Among GNB, 25% were extended-spectrum beta-lactamase producers while 62.5% were carbapenemase producers. All GNBs were sensitive to colistin. Conclusion: From this study, we concluded that the pathogenic bacteria implicated in infections of sterile body fluids are predominantly multidrug-resistant. There is a huge variation in data on the distribution of bacterial species isolated from sterile body fluids and their antimicrobial resistance patterns from different geographical locations and healthcare settings. Thus, data from a particular healthcare setting are important for empirical treatment in that healthcare setting.

#AMRrounds: a systematic educational approach for navigating bench to bedside antimicrobial resistance.

Antimicrobial resistance (AMR) continues to serve as a major global health crisis. Clinicians practising in this modern era are faced with ongoing challenges in the therapeutic management of patients suffering from antimicrobial-resistant infections. A strong educational understanding and synergistic application of clinical microbiology, infectious disease and pharmacological concepts can assist the adventuring clinician in the navigation of such cases. Important items include mobilizing laboratory testing for pathogen identification and susceptibility data, harnessing an understanding of intrinsic pathogen resistance, acknowledging epidemiological resistance trends, recognizing acquired AMR mechanisms, and consolidating these considerations when constructing an ideal pharmacological plan. In this article, we outline a novel framework by which to systematically approach clinical AMR, encourage AMR-related education and optimize therapeutic decision-making in AMR-related illnesses.

Biofilm Inhibition, Antibacterial and Antiadhesive Properties of a Novel Biosurfactant from Lactobacillus paracasei N2 against Multi-Antibiotics-Resistant Pathogens Isolated from Braised Fish

This study aimed to assess the antibiotic susceptibility and biofilm formation ability of pathogens isolated from braised fish as well as characterize and evaluate the antibacterial, antiadhesive, and antibiofilm activities of the biosurfactant from Lactobacillus paracasei subsp. tolerans N2 against these pathogens. The susceptibility of six pathogens isolated from braised fish (Escherichia coli EM2, Staphylococcus aureus SA1, Salmonella enteritidis PE1, Pseudomonas aeruginosa CT3, Yersinia enterolitica MH5, Proteus mirabilis MR2, and Klebsiella pneumoniae AG5) to 16 antibiotics revealed multiple resistances with an MAR index greater than 0.3. These pathogens were able to form biofilms with S. aureus SA1, which showed the highest ability. Using biochemical and elemental analyses, FTIR, GC-MS, 1H NMR and high-resolution mass spectrometry, the biosurfactant was characterized as a novel glycolipoprotein made of two congeners of mass 482.28 and 507.27 m/z, respectively. They showed bactericidal and antiadhesive activities against all pathogens. The biosurfactant inhibited biofilm formation by these pathogens and eradicated mature biofilms.

Role of rapid tests in diagnosis of bloodstream infections and their effect on promoting antibiotic stewardship among febrile neutropenic patients in Alexandria

Abstract Background Bloodstream infections (BSIs) in neutropenic patients significantly contribute to morbidity and mortality. The rapid identification and determination of antimicrobial susceptibility of pathogens causing BSIs can help in early initiation of targeted antimicrobial therapy and allow de-escalation of unnecessary empirical antimicrobials. Aim This study evaluated the rapidity and accuracy of gram-stained smear from blood culture bottles and direct VITEK 2 to identify and determine antimicrobial susceptibility of pathogens causing BSIs and assessed the effect of these tests on modification of empiric therapy. Patients and methods Blood cultures were collected from 100 febrile neutropenic patients from the Hematology Unit in Alexandria Main University Hospital. Gram-stained smears were prepared from blood culture bottles; blood from bottles with suggestive smears was directly inoculated into the VITEK 2 system, and results were compared with conventional methods. Results were instantly reported to clinicians. Empirical antimicrobials and their modification were recorded. Results BSI was detected in 30% of patients. Gram-negative bacteremia was predominant (24/30). Gram-stained smears showed complete accordance with conventional methods in 99 samples. VITEK 2 correctly identified all tested microorganisms, and the overall agreement in susceptibility testing was 100 and 95.2% for gram-positive and gram-negative bacteria, respectively. The effect of these rapid tests on empiric antimicrobial therapy was evident in 12 of 30 patients with documented BSIs (40%). Conclusion Gram-stained smear and direct VITEK 2 testing when integrated with instant reporting is a valid approach to guide targeted therapy in neutropenic patients in the context of extremely resistant pathogens.

Contrast-enhanced ultrasound imaging for assessment of intestinal inflammation in rainbow trout

The intestine is essential for nutritional uptake and as a barrier to pathogens. Inflammation of the intestine can result from chemical contaminants, dietary irritants, or disease and may lead to serious health consequences, including reduced growth rates or increased pathogen susceptibility. Traditionally, intestinal inflammation in fish has been detected through histology completed post-mortem through excision and processing of the affected tissue. However, in human clinical settings, tools have been developed to assess intestinal inflammation non-invasively. Contrast-enhanced ultrasound (CEUS) imaging is an important tool for measuring inflammation in patients because it is cost-effective and minimally invasive. Specifically, CEUS allows real-time visualization and quantification of vascular perfusion. Changes in blood flow are typical in areas of inflamed or diseased tissue, and by measuring these changes, it is possible to assess the degree of inflammation. We demonstrate that standard CEUS protocols used for small mammals can be used to quantify vascular perfusion in the intestines of rainbow trout. Our resolution was sufficient to measure a significant difference in perfusion between control and TNBS-inflamed trout intestines, with inflamed intestines showing decreased perfusion. The presence of inflammation in the TNBS-treated intestines was verified ex vivo histologically and was characterized by the thickening of intestinal folds. The minimally invasive nature of CEUS imaging presents the opportunity to evaluate intestinal health in novel ways by allowing for longitudinal observations and avoiding mortality in valuable or at-risk specimens. Recent developments of highly portable, cost-effective CEUS systems will allow broad application of this tool, from industry to research.

Novel evidence on sepsis-inducing pathogens: from laboratory to bedside.

Sepsis is a life-threatening condition and a significant cause of preventable morbidity and mortality globally. Among the leading causative agents of sepsis are bacterial pathogens Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, and Streptococcus pyogenes, along with fungal pathogens of the Candida species. Here, we focus on evidence from human studies but also include in vitro and in vivo cellular and molecular evidence, exploring how bacterial and fungal pathogens are associated with bloodstream infection and sepsis. This review presents a narrative update on pathogen epidemiology, virulence factors, host factors of susceptibility, mechanisms of immunomodulation, current therapies, antibiotic resistance, and opportunities for diagnosis, prognosis, and therapeutics, through the perspective of bloodstream infection and sepsis. A list of curated novel host and pathogen factors, diagnostic and prognostic markers, and potential therapeutical targets to tackle sepsis from the research laboratory is presented. Further, we discuss the complex nature of sepsis depending on the sepsis-inducing pathogen and host susceptibility, the more common strains associated with severe pathology and how these aspects may impact in the management of the clinical presentation of sepsis.

Potent antibacterial activity in surgical wounds with local administration of D-PLEX100

Despite significant advances in infection control guidelines and practices, surgical site infections remain a substantial cause of morbidity, prolonged hospitalization, and mortality. The most effective component of SSI reduction strategies is the preoperative administration of intravenous antibiotics; however, systemic antibiotics drug exposure diminishes rapidly and may result in insufficient prophylactic activity against susceptible and resistant SSI pathogens at the wound. D-PLEX100 (D-PLEX) is an antibiotic-releasing drug (doxycycline) that is supplied as a sterile powder for paste reconstitution with sterile saline. D-PLEX paste is administered locally into the incision site along the entire length of soft tissue and sternal bone wound surfaces prior to skin closure. A single D-PLEX administration is intended for 30 days of constant antimicrobial prophylaxis in the prevention of incisional SSIs. We evaluated D-PLEX minimal bactericidal concentration (MBC) against a panel of bacteria that is prevalent in the abdominal wall and sternal surgical procedures including doxycycline susceptible and resistant strains. D-PLEX in vivo efficacy was assessed in incisional infection rabbit models (abdominal wall and sternal) challenged with a similar bacterial panel. The D-PLEX drug exposure profile was determined by in vitro release assay, and in vivo by quantitative pharmacokinetic parameters of local and systemic doxycycline concentrations released from D-PLEX after local administration in incisional rabbit models. Analyses of pathogens and variations in antibiotic resistance from wound isolates were determined from patients who participated in a previously reported prospective randomized trial that assessed the SSI rate in D-PLEX plus standard of care (SOC) versus SOC alone in colorectal resection surgery. The D-PLEX MBC values demonstrated >3- Log10 reduction in all the organisms tested relative to untreated controls, including doxycycline-resistant bacteria (i.e., Methicillin-resistant Staphylococcus aureus (MRSA), K. pneumoniae, and P. aeruginosa). In vivo, D-PLEX significantly reduced the bacterial loads in all the bacteria tested in both animal models (p=0.0001) with a marked impact observed in E. Coli (>6.5 Log10 reduction). D-PLEX exhibited a zero-order release kinetics profile in vitro for 30 days (R2 = 0.971) and the matched in vivo release profile indicated a constant local release of protein-unbound doxycycline for 30 days at 3-5 mcg/mL with significantly lower (>3 orders of magnitudes) systemic levels. In colorectal surgery patients, where significant SSI reduction was observed, analysis of the positive cultures in the overall population indicated similar pathogen diversity and antibiotic resistance rates in both treatment arms. However, almost all the patients with positive culture in the SOC arm were adjudicated as SSI (94%) compared to only 28% in the D-PLEX arm. The SSI-adjudicated D-PLEX patients also exhibited lower resistance rates to the SOC antibiotics and to MDRs compared to patients in the SOC arm. Thus, D-PLEX provides safe and effective prophylaxis activity against the most prevalent SSI pathogens including doxycycline-susceptible and resistant bacteria. Our findings suggest that D-PLEX is a promising addition to SSI prophylactic bundles and may address the gaps in current SSI prophylaxis. D-PLEX is now evaluated in Phase 3 clinical trial.

Neonatal sepsis: Challenges in data access, harmonisation and analysis to inform empirical antibiotic recommendations in South African neonatal units

&#x0D; &#x0D; &#x0D; Severe bacterial and fungal infections (sepsis) are a leading cause of mortality among neonates in sub-Saharan Africa. In African neonatal units, most sepsis episodes are hospital acquired, and caused by Gram-negative, antimicrobial-resistant pathogens. With rising rates of antimicrobial resistance (AMR) in neonatal sepsis pathogens, there is an increasing probability of inappropriate empirical antibiotic therapy (so called ‘bug-drug’ mismatch or discordant therapy), as confirmation of pathogen identity and antibiotic susceptibility pattern is either not available or delayed. The impact of AMR and discordant empirical treatment on neonatal sepsis outcomes in Africa is largely unknown owing to the lack of the infection surveillance data needed to derive empirical antibiotic treatment recommendations. The Antibiotics for Neonatal Sepsis in Africa (ANSA) study will address this data gap by pooling and harmonising available single-centre research datasets and/or routine laboratory blood culture data to determine which antibiotics should be used for empirical treatment of neonatal sepsis. However, many challenges hamper these datasets, including: variable laboratory methods for pathogen identification and susceptibility testing; difficulty in collating and harmonising data from multiple sites; problems of record linkage in the absence of a single patient identifier; lack of centralised health data capturing systems; and difficulty accessing data due to complex data sharing agreements and custodian permissions. To overcome some of these challenges, minimum guidelines for the collection of neonatal sepsis data need to be defined, to ensure consistency between datasets. Greater collection of, access to and sharing of neonatal sepsis data from institutional, provincial and national laboratories, as well as individual neonatal units, would enable the establishment of a neonatal surveillance network. Development of a sustainably-funded neonatal sepsis surveillance network is a national priority, to ensure effective, evidence-based antimicrobial treatment of hospitalised neonates in South Africa.&#x0D; &#x0D; &#x0D;

Neonatal sepsis: Challenges in data access, harmonisation and analysis to inform empirical antibiotic recommendations in South African neonatal units

&#x0D; &#x0D; &#x0D; Severe bacterial and fungal infections (sepsis) are a leading cause of mortality among neonates in sub-Saharan Africa. In African neonatal units, most sepsis episodes are hospital acquired, and caused by Gram-negative, antimicrobial-resistant pathogens. With rising rates of antimicrobial resistance (AMR) in neonatal sepsis pathogens, there is an increasing probability of inappropriate empirical antibiotic therapy (so called ‘bug-drug’ mismatch or discordant therapy), as confirmation of pathogen identity and antibiotic susceptibility pattern is either not available or delayed. The impact of AMR and discordant empirical treatment on neonatal sepsis outcomes in Africa is largely unknown owing to the lack of the infection surveillance data needed to derive empirical antibiotic treatment recommendations. The Antibiotics for Neonatal Sepsis in Africa (ANSA) study will address this data gap by pooling and harmonising available single-centre research datasets and/or routine laboratory blood culture data to determine which antibiotics should be used for empirical treatment of neonatal sepsis. However, many challenges hamper these datasets, including: variable laboratory methods for pathogen identification and susceptibility testing; difficulty in collating and harmonising data from multiple sites; problems of record linkage in the absence of a single patient identifier; lack of centralised health data capturing systems; and difficulty accessing data due to complex data sharing agreements and custodian permissions. To overcome some of these challenges, minimum guidelines for the collection of neonatal sepsis data need to be defined, to ensure consistency between datasets. Greater collection of, access to and sharing of neonatal sepsis data from institutional, provincial and national laboratories, as well as individual neonatal units, would enable the establishment of a neonatal surveillance network. Development of a sustainably-funded neonatal sepsis surveillance network is a national priority, to ensure effective, evidence-based antimicrobial treatment of hospitalised neonates in South Africa.&#x0D; &#x0D; &#x0D;

P02 Antimicrobial susceptibility of microorganisms isolated in community-acquired pneumonia in drug-dependent patients

Abstract Objectives To investigate the nature and susceptibility of community-acquired pneumonia (CAP) pathogens in drug-dependent patients. Materials and methods The susceptibility of community-acquired pneumonia pathogens isolated from sputum was studied in 31 drug-dependent patients. 13 (42%) were women and 18 (58%) were men. The average age of this group was 28.6 ± 1.2 years. The antimicrobial activity of the main groups of antibiotics was studied in comparison with the susceptibility of the archive Staphylococcus aureus ATCC25923 strain. Results In total, 51 strains of microorganisms were isolated, among which S. aureus (19 strains, 37.3%) and fungi of the genus Candida (16 strains, 31.3%) prevailed, while in 15 cases, bacteria were inoculated in the form of monoculture, and in 16 cases in the form of associations of bacteria and fungi of the genus Candida. When studying the susceptibility of the isolated strains of microorganisms to the main groups of antibiotics, their high (P ≤ 0.05) resistance to the main groups of antimicrobial drugs used in standard treatment regimens for CAP was established. Conclusions CAP in drug-dependent patients has a severe complicated course due to the combination of highly virulent bacterial and fungal infections. The causative agents of community-acquired pneumonia in drug-dependent patients have low susceptibility to the main groups of antibiotics used in the treatment of this pathology.

PHOTOSYNTHETIC MICROORGANISMS AS SOURCE OF ANTIOXIDANT AND ANTIBACTERIAL BIOACTIVE COMPOUNDS OF INTEREST IN THE FOOD INDUSTRY

Bioactive compounds from microalgae and cyanobacteria have been frequently investigated as food preservatives due to their various biotechnological activities. Therefore, this study aimed to evaluate the antimicrobial and antioxidant activities of the aqueous and ethanolic extracts from Dunaliella tertiolecta, Tetradesmus obliquus, and Chlorella vulgaris microalgae and Arthrospira platensis cyanobacteria. The extracts were obtained through the sonication method and the antioxidant activity was determined by ABTS and DPPH methods, whereas antimicrobial activity was evaluated by microdilution assay. In general, ethanolic extracts of all microalgae showed higher antioxidant activity compared to aqueous extracts, especially using ABTS method. All bacteria exhibited higher resistance using the aqueous extracts. Specifically, the gram-negative Pseudomonas aeruginosa was the most susceptible pathogen and was inhibited by all microalgae. The highest antioxidant and antimicrobial activities were obtained by the ethanolic extract from Arthrospira platensis. These data show that ethanolic extract from Arthrospira platensis may be a potential source of antioxidant and antimicrobial compounds with food preservative properties.

Antibiotic resistance in healthcare associated infections: An Empirical Study causes and consequences

Antimicrobial resistance has arisen as a considerable worldwide health predicament, especially in the framework of healthcare-connected infections (HAIs). HAIs occur during medical treatment and frequently affect vulnerable patient populations, resulting in elevated morbidity, mortality, and healthcare expenses. This abridgment scrutinizes the roots and repercussions of antibiotic resistance in HAIs. The leading cause of antibiotic resistance in HAIs is the superfluous and erroneous use of antibiotics. The broad and indiscriminate application of these medications has resulted in selective pressure on bacteria, advancing the endurance and propagation of resistant strains. Additionally, the spread of resistance genes between bacteria compounds the issue. Poor infection control methodologies, substandard hygiene, and unsatisfactory antimicrobial stewardship programs within healthcare centers also contribute to the generation and dissemination of antibiotic resistance. The aftermath of antibiotic resistance in HAIs is profound. Patients affected by antibiotic-resistant infections experience protracted hospital stays, heightened treatment shortcomings, and elevated mortality rates contrasted with those infected by susceptible pathogens. Moreover, the restricted availability of effective antibiotics obstructs treatment alternatives, leading to the use of last-resort antibiotics with latent toxicities and greater costs

Antimicrobial Susceptibility of Pasteurella multocida Isolated from Sheep with Fibrinous Pneumonia

Abstract Ovine respiratory complex is a significant cause of death in sheep flocks, where Pasteurella multocida is the most frequent microorganisms isolated from animals with pneumonia. There is an urgent need to refine the use of different antimicrobials to avoid the problem of antimicrobial resistance and optimize the control of this disease in ovine livestock. The first step in approaching this problem is gaining an insight into the antimicrobial susceptibility of ovine pathogens. This study evaluated the in vitro activity of tildipirosin, gamithromycin, oxytetracycline, and danofloxacin against Pasteurella multocida strains isolated from sheep with fibrinous pneumonia. The strains were incubated following Clinical and Laboratory Standards Institute (CLSI) standard conditions and also with a modified method by 25% supplementation with sheep serum. Minimum inhibitory concentrations (MIC) were determined using the broth microdilution technique. The lowest MIC90 under standard conditions and by supplementation with sheep serum was obtained with tildipirosin. Sheep serum significantly reduced tildipirosin, gamithromycin, and danofloxacin MIC values for Pasteurella multocida strains. In brief, the potency of tildipirosine, gamithromycin, and danofloxacin against Pasteurella multocida increases when sheep serum is added to the culture media.

Using bacterial pan-genome-based feature selection approach to improve the prediction of minimum inhibitory concentration (MIC).

Background: Predicting the resistance profiles of antimicrobial resistance (AMR) pathogens is becoming more and more important in treating infectious diseases. Various attempts have been made to build machine learning models to classify resistant or susceptible pathogens based on either known antimicrobial resistance genes or the entire gene set. However, the phenotypic annotations are translated from minimum inhibitory concentration (MIC), which is the lowest concentration of antibiotic drugs in inhibiting certain pathogenic strains. Since the MIC breakpoints that classify a strain to be resistant or susceptible to specific antibiotic drug may be revised by governing institutes, we refrained from translating these MIC values into the categories "susceptible" or "resistant" but instead attempted to predict the MIC values using machine learning approaches. Results: By applying a machine learning feature selection approach on a Salmonella enterica pan-genome, in which the protein sequences were clustered to identify highly similar gene families, we showed that the selected features (genes) performed better than known AMR genes, and that models built on the selected genes achieved very accurate MIC prediction. Functional analysis revealed that about half of the selected genes were annotated as hypothetical proteins (i.e., with unknown functional roles), and that only a small portion of known AMR genes were among the selected genes, indicating that applying feature selection on the entire gene set has the potential of uncovering novel genes that may be associated with and may contribute to pathogenic antimicrobial resistances. Conclusion: The application of the pan-genome-based machine learning approach was indeed capable of predicting MIC values with very high accuracy. The feature selection process may also identify novel AMR genes for inferring bacterial antimicrobial resistance phenotypes.