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Journal of Investigative Medicine High... 2024Hemophagocytic lymphohistiocytosis (HLH) secondary to is rare, impacting <1% globally, with a mortality rate of up to 31%. Herein, we present a rare case of HLH... (Review)
Review
Hemophagocytic lymphohistiocytosis (HLH) secondary to is rare, impacting <1% globally, with a mortality rate of up to 31%. Herein, we present a rare case of HLH secondary to , affecting a 57-year-old female with rheumatoid arthritis. Extensive investigations were unrevealing and despite broad-spectrum antibiotics, her condition worsened, leading to respiratory failure requiring extracorporeal membrane oxygenation (ECMO) support, shock requiring multiple vasopressors, and acute kidney injury (AKI) requiring hemodialysis. Diagnosis confirmed disseminated histoplasmosis (DHP), prompting Amphotericin B and methylprednisolone treatment, resulting in significant improvement and discharge with posaconazole therapy. Secondary HLH, primarily arising from severe infections like DHP, is discussed. Limited research exists on this condition in human immunodeficiency virus (HIV)-seronegative individuals. Diagnosis involves HLH-2004 and HScore criteria. Managing histoplasmosis-associated HLH remains challenging due to multiorgan failure risks and treatment complexities and needs further research.
Topics: Humans; Lymphohistiocytosis, Hemophagocytic; Histoplasmosis; Female; Middle Aged; Antifungal Agents; Histoplasma; Amphotericin B
PubMed: 38813977
DOI: 10.1177/23247096241258074 -
Frontiers in Cellular and Infection... 2024Antibiotic drug combination therapy is critical for the successful treatment of infections caused by multidrug resistant pathogens. We investigated the efficacy of...
Antibiotic drug combination therapy is critical for the successful treatment of infections caused by multidrug resistant pathogens. We investigated the efficacy of β-lactam and β-lactam/β-lactamase inhibitor combinations with other antibiotics, against the hypervirulent, ceftazidime/avibactam resistant Liverpool epidemic strain (LES) B58. Although minimum inhibitory concentrations differed by up to eighty-fold between standard and host-mimicking media, combinatorial effects only marginally changed between conditions for some combinations. Effective combinations were further tested in a chronic, high-density murine infection model. Colistin and azithromycin demonstrated combinatorial effects with ceftazidime and ceftazidime/avibactam both and . Conversely, while tobramycin and tigecycline exhibited strong synergy , this effect was not observed . Our approach of using host-mimicking conditions and a sophisticated animal model to evaluate drug synergy against bacterial pathogens represents a promising approach. This methodology may offer insights into the prediction of combination therapy outcomes and the identification of potential treatment failures.
Topics: Animals; Pseudomonas aeruginosa; Drug Synergism; Anti-Bacterial Agents; Disease Models, Animal; Pseudomonas Infections; Mice; Microbial Sensitivity Tests; Drug Therapy, Combination; Abscess; Drug Combinations; Drug Resistance, Multiple, Bacterial; Female; Ceftazidime; Azithromycin; Azabicyclo Compounds; Colistin
PubMed: 38808066
DOI: 10.3389/fcimb.2024.1352339 -
Scientific Reports May 2024Heterogeneity of Helicobacter pylori communities contributes to its pathogenicity and diverse clinical outcomes. We conducted drug-susceptibility tests using four...
Heterogeneity of Helicobacter pylori communities contributes to its pathogenicity and diverse clinical outcomes. We conducted drug-susceptibility tests using four antibiotics, clarithromycin (CLR), amoxicillin (AMX), metronidazole and sitafloxacin, to examine H. pylori population diversity. We also analyzed genes associated with resistance to CLR and AMX. We examined multiple isolates from 42 Japanese patients, including 28 patients in whom primary eradication with CLR and AMX had failed, and 14 treatment-naïve patients. We identified some patients with coexistence of drug resistant- and sensitive-isolates (drug-heteroR/S-patients). More than 60% of patients were drug-heteroR/S to all four drugs, indicating extensive heterogeneity. For the four drugs except AMX, the rates of drug-heteroR/S-patients were higher in treatment-naïve patients than in primary eradication-failure patients. In primary eradication-failure patients, isolates multi-resistant to all four drugs existed among other isolates. In primary eradication-failure drug-heteroR/S-patients, CLR- and AMX-resistant isolates were preferentially distributed to the corpus and antrum with different minimum inhibitory concentrations, respectively. We found two mutations in PBP1A, G591K and A480V, and analyzed these in recombinants to directly demonstrate their association with AMX resistance. Assessment of multiple isolates from different stomach regions will improve accurate assessment of H. pylori colonization status in the stomach.
Topics: Humans; Helicobacter pylori; Microbial Sensitivity Tests; Helicobacter Infections; Anti-Bacterial Agents; Mutation; Drug Resistance, Bacterial; Amoxicillin; Male; Female; Metronidazole; Stomach; Clarithromycin; Middle Aged; Aged; Adult; Bacterial Proteins; Penicillin-Binding Proteins; Fluoroquinolones
PubMed: 38802465
DOI: 10.1038/s41598-024-62200-1 -
Journal of Global Antimicrobial... May 2024The emergence of antimicrobial-resistant and mastitis-associated Enterococcus faecalis and Enterococcus faecium is of great concern due to the huge economic losses...
Draft genome sequences of clinical mastitis-associated Enterococcus faecalis and Enterococcus faecium carrying multiple antimicrobial resistance genes isolated from dairy cows.
OBJECTIVES
The emergence of antimicrobial-resistant and mastitis-associated Enterococcus faecalis and Enterococcus faecium is of great concern due to the huge economic losses associated with enterococcal infections. Here we report the draft genome sequences of Enterococcus faecalis and Enterococcus faecium strains which were isolated from raw milk samples obtained from mastitis-infected cows in Bangladesh.
METHODS
Strains were isolated, identified and Genomic DNA was sequenced using Illumina NextSeq 550 platform. The assembled contigs were analyzed for virulence, antimicrobial resistance genes, and multi-locus sequence type. The genomes were compared to previously reported Enterococcus faecalis and Enterococcus faecium genomes to generate core genome phylogenetic trees.
RESULTS
Enterococcus faecalis strain BR-MHR218Efa and Enterococcus faecium strain BR-MHR268Efe belonged to multilocus sequence type ST-190 and ST-22, respectively. Both sequence types seem to represent relatively rare sequence types. BR-MHR268Efe harbored only one antibiotic resistance gene encoding resistance towards macrolides (lsa(A)), while BR-MHR218Efa harbored ten different antibiotic resistance genes encoding resistance to aminoglycosides (ant[6]-Ia, aph(3')-III), sulphonamides (aac(6')-II), lincosamides (lnu(B)), macrolides (erm(B)), MLSB antibiotics (msr(C)), tetracyclines (tet(M), tet(L)), trimethoprim (dfrG) and pleuromutilin-lincosamide-streptogramin A (lsa(E)).The virulence gene composition was different in the two isolates. BR-MHR218Efa harbored only two virulence genes involved in adherence (acm, scm). BR-MHR268Efe harbored eight complete virulence operons including three operons involved in adherence (Ace, Ebp pili, EfaA), two operons involved in biofilm formation (BopD, Fsr) and three exoenzymes (gelatinase, hyaluronidase, SprE).
CONCLUSIONS
The genome sequences of strains BR-MHR268Efe and BR-MHR218Efa will serve as a reference point for molecular epidemiological studies of mastitis-associated Enterococcus faecalis and Enterococcus faecium. Additionally, the findings will help the understand the complex antimicrobial resistant livestock Enterococci.
PubMed: 38795772
DOI: 10.1016/j.jgar.2024.05.011 -
Pharmaceutics May 2024The threat of antibiotic resistance of fungal pathogens and the high toxicity of the most effective drugs, polyene macrolides, force us to look for new ways to develop...
BACKGROUND
The threat of antibiotic resistance of fungal pathogens and the high toxicity of the most effective drugs, polyene macrolides, force us to look for new ways to develop innovative antifungal formulations.
OBJECTIVE
The aim of this study was to determine how the sterol, phospholipid, and flavonoid composition of liposomal forms of polyene antibiotics, and in particular, amphotericin B (AmB), affects their ability to increase the permeability of lipid bilayers that mimic the membranes of mammalian and fungal cells.
METHODS
To monitor the membrane permeability induced by various polyene-based lipid formulations, a calcein leakage assay and the electrophysiological technique based on planar lipid bilayers were used.
KEY RESULTS
The replacement of cholesterol with its biosynthetic precursor, 7-dehydrocholesterol, led to a decrease in the ability of AmB-loaded liposomes to permeabilize lipid bilayers mimicking mammalian cell membranes. The inclusion of plant flavonoid phloretin in AmB-loaded liposomes increased the ability of the formulation to disengage a fluorescent marker from lipid vesicles mimicking the membranes of target fungi. - characteristics of the fungal-like lipid bilayers treated with the AmB phytosomes were symmetric, demonstrating the functioning of double-length AmB pores and assuming a decrease in the antibiotic threshold concentration.
CONCLUSIONS AND PERSPECTIVES
The therapeutic window of polyene lipid formulations might be expanded by varying their sterol composition. Polyene-loaded phytosomes might be considered as the prototypes for innovative lipid antibiotic formulations.
PubMed: 38794328
DOI: 10.3390/pharmaceutics16050665 -
Microorganisms Apr 2024() is a zoonotic pathogen capable of causing severe diseases in humans and pigs, including meningitis, sepsis, polyserositis, arthritis, and endocarditis. This study...
() is a zoonotic pathogen capable of causing severe diseases in humans and pigs, including meningitis, sepsis, polyserositis, arthritis, and endocarditis. This study aimed to investigate the biological characteristics of 19 strains of isolated from diseased pigs in Hubei Province between 2021 and 2023. Through bioinformatics analysis, we investigated the serotype, MLST, pan-genome characteristics, SNP, AMR, and ICE of the 19 isolates. Among the 19 strains, ten serotypes were identified, and serotype 9 was the most prevalent (21.05%). Ten new alleles and nine new sequence types (STs) were discovered, with ST28 and ST243 emerging as the predominant STs. The results of the pan-genomic analysis of indicate that there are 943 core genes, 2259 shell genes, and 5663 cloud genes. Through SNP evolutionary analysis, we identified a strong genetic similarity between SS31 and the reference genome P1/7. The analysis of antibiotic resistance genes revealed widespread presence of (B) and (O) genes among 19 strains of . This association may be linked to the high resistance of to lincosamides, macrolides, and tetracyclines. Integrative and conjugative elements (ICEs) and integrative and mobilizable elements (IMEs) were identified in 16 strains, with a carriage rate of 84.21%, and resistance genes were identified within the ICE/IME elements of 8 strains. Antimicrobial susceptibility testing revealed that all strains showed sensitivity to vancomycin and lincomycin but resistance to tilmicosin, tiamulin, amoxicillin, and doxycycline. This study contributes to our understanding of the genomic diversity of in Hubei Province of China, providing essential data for the comprehensive prevention and control of infections in China.
PubMed: 38792744
DOI: 10.3390/microorganisms12050917 -
International Journal of Molecular... May 2024Lefamulin is a first-in-class systemic pleuromutilin antimicrobial and potent inhibitor of bacterial translation, and the most recent novel antimicrobial approved for...
Lefamulin is a first-in-class systemic pleuromutilin antimicrobial and potent inhibitor of bacterial translation, and the most recent novel antimicrobial approved for the treatment of community-acquired pneumonia (CAP). It exhibits potent antibacterial activity against the most prevalent bacterial pathogens that cause typical and atypical pneumonia and other infectious diseases. Early studies indicate additional anti-inflammatory activity. In this study, we further investigated the immune-modulatory activity of lefamulin in the influenza A/H1N1 acute respiratory distress syndrome (ARDS) model in BALB/c mice. Comparators included azithromycin, an anti-inflammatory antimicrobial, and the antiviral oseltamivir. Lefamulin significantly decreased the total immune cell infiltration, specifically the neutrophils, inflammatory monocytes, CD4 and CD8 T-cells, NK cells, and B-cells into the lung by Day 6 at both doses tested compared to the untreated vehicle control group (placebo), whereas azithromycin and oseltamivir did not significantly affect the total immune cell counts at the tested dosing regimens. Bronchioalveolar lavage fluid concentrations of pro-inflammatory cytokines and chemokines including TNF-α, IL-6, IL-12p70, IL-17A, IFN-γ, and GM-CSF were significantly reduced, and MCP-1 concentrations were lowered (not significantly) by lefamulin at the clinically relevant 'low' dose on Day 3 when the viral load peaked. Similar effects were also observed for oseltamivir and azithromycin. Lefamulin also decreased the viral load (TCID) by half a log10 by Day 6 and showed positive effects on the gross lung pathology and survival. Oseltamivir and lefamulin were efficacious in the suppression of the development of influenza-induced bronchi-interstitial pneumonia, whereas azithromycin did not show reduced pathology at the tested treatment regimen. The observed anti-inflammatory and immune-modulatory activity of lefamulin at the tested treatment regimens highlights a promising secondary pharmacological property of lefamulin. While these results require confirmation in a clinical trial, they indicate that lefamulin may provide an immune-modulatory activity beyond its proven potent antibacterial activity. This additional activity may benefit CAP patients and potentially prevent acute lung injury (ALI) and ARDS.
Topics: Animals; Influenza A Virus, H1N1 Subtype; Mice; Mice, Inbred BALB C; Orthomyxoviridae Infections; Disease Models, Animal; Diterpenes; Cytokines; Azithromycin; Oseltamivir; Female; Lung; Antiviral Agents; Tetrahydronaphthalenes; Respiratory Distress Syndrome; Immunomodulating Agents; Bronchoalveolar Lavage Fluid; Polycyclic Compounds; Thioglycolates
PubMed: 38791439
DOI: 10.3390/ijms25105401 -
Antibiotics (Basel, Switzerland) May 2024Antimicrobial resistance (AMR) among from food animals is a rising problem, and heavy antimicrobial use in poultry is a contributing factor. In Zambia, studies linking...
Antimicrobial resistance (AMR) among from food animals is a rising problem, and heavy antimicrobial use in poultry is a contributing factor. In Zambia, studies linking poultry-associated AMR and antibiotic use (AMU) are rare. This study aimed to investigate commercial and medium-/small-scale poultry farmers' usage of antimicrobials based on a questionnaire survey in ten districts of Zambia. In addition, the study characterized extended-spectrum -lactamase (ESBL)-producing isolates obtained from poultry in the same districts. Data regarding knowledge and usage of antimicrobials were collected from commercial and medium-/small-scale poultry farmers using a pre-tested structured questionnaire. At the same time, cloacal samples were collected and analyzed. One hundred and fifty isolates were tested for antimicrobial susceptibility using eight antibiotic classes. The isolates were further screened for ESBL production by streaking them on cefotaxime (CTX)-supplemented MacConkey agar, then subjecting them to sequencing on a NextSeq. The questionnaire survey showed that more medium-/small-scale than commercial poultry farmers used antimicrobials (OR = 7.70, 95% CI = 2.88-20.61) but less prescriptions (OR = 0.02, 95% CI = 0.00-0.08). Susceptibility testing revealed that resistance was highest to ampicillin (128/148, 86.5%) and tetracycline (101/136, 74.3%) and that the prevalence of multidrug resistance (MDR) (28/30, 93.3%) was high. Whole-genome sequencing (WGS) of eight (8/30, 26.7%) isolates with CTX Minimum Inhibitory Concentration (MIC) ≥ 4 µg/mL revealed the presence of ESBL-encoding genes , , and . WGS also detected other AMR genes for quinolones, aminoglycosides, phenicols, tetracycline, macrolides, and folate-pathway antagonists. Altogether, the questionnaire survey results showed a higher proportion of AMU and lower prescription usage among medium-/small-scale farmers. In addition, our results emphasize the circulation of ESBL-producing strains with associated MDR. It is critical to educate farmers about AMR risks and to encourage responsible usage of antimicrobials. Furthermore, there is a need to strengthen regulations limiting access to antimicrobials. Finally, there is a need to establish a one health system to guide public health response.
PubMed: 38786195
DOI: 10.3390/antibiotics13050467 -
Antibiotics (Basel, Switzerland) May 2024Actinomycetes have long been recognized as important sources of clinical antibiotics. However, the exploration of rare actinomycetes, despite their potential for...
Actinomycetes have long been recognized as important sources of clinical antibiotics. However, the exploration of rare actinomycetes, despite their potential for producing bioactive molecules, has remained relatively limited compared to the extensively studied genus. The extensive investigation of species and their natural products has led to a diminished probability of discovering novel bioactive compounds from this group. Consequently, our research focus has shifted towards less explored actinomycetes, beyond , with particular emphasis on (). The genome of was annotated and analyzed through whole-genome sequencing using multiple bio-informatics tools, revealing an 8.6 Mbp genome with a 74.42% G + C content. AntiSMASH analysis identified 40 putative biosynthetic gene clusters (BGCs), approximately half of which were recessive and unknown. Additionally, metabolomic mining utilizing mass spectrometry demonstrated the potential for this rare actinomycete to generate numerous bioactive compounds such as glycosides and macrolides, with bafilomycin being the major compound produced. Collectively, genomics- and metabolomics-based techniques confirmed 's potential as a bioactive secondary metabolite producer that is worthy of further exploration.
PubMed: 38786187
DOI: 10.3390/antibiotics13050459 -
Antibiotics (Basel, Switzerland) May 2024The recognition of the complex (AUC) as an emerging uropathogen has led to growing concerns due to a limited understanding of its disease spectrum and antibiotic...
The recognition of the complex (AUC) as an emerging uropathogen has led to growing concerns due to a limited understanding of its disease spectrum and antibiotic resistance profiles. Here, we investigated the prevalence of macrolide resistance within urinary AUC isolates, shedding light on potential genetic mechanisms. Phenotypic testing revealed a high rate of macrolide resistance: 45%, among a total of 189 urinary AUC isolates. Genomic analysis identified integrative and conjugative elements (ICEs) as carriers of the macrolide resistance gene , suggesting horizontal gene transfer as a mechanism of resistance. Furthermore, comparison with publicly available genomes of related pathogens revealed high ICE sequence homogeneity, highlighting the potential for cross-species dissemination of resistance determinants. Understanding mechanisms of resistance is crucial for developing effective surveillance strategies and improving antibiotic use. Furthermore, the findings underscore the importance of considering the broader ecological context of resistance dissemination, emphasizing the need for community-level surveillance to combat the spread of antibiotic resistance within the urinary microbiome.
PubMed: 38786161
DOI: 10.3390/antibiotics13050433