Mechanisms of antimicrobial resistance in biofilms.

Most bacteria in nature exist in aggregated communities known as biofilms, and cells within a biofilm demonstrate major physiological changes compared to their planktonic counterparts. Biofilms are associated with many different types of infections which can have severe impacts on patients. Infections involving a biofilm component are often chronic and highly recalcitrant to antibiotic therapy as a result of intrinsic physical factors including extracellular matrix production, low growth rates, altered antibiotic target production and efficient exchange of resistance genes. This review describes the biofilm lifecycle, phenotypic characteristics of a biofilm, and contribution of matrix and persister cells to biofilms intrinsic tolerance to antimicrobials. We also describe how biofilms can evolve antibiotic resistance and transfer resistance genes within biofilms. Multispecies biofilms and the impacts of various interactions, including cooperation and competition, between species on tolerance to antimicrobials in polymicrobial biofilm communities are also discussed.

Identification of proteotoxic and proteoprotective bacteria that non-specifically affect proteins associated with neurodegenerative diseases.

There are no cures for neurodegenerative protein conformational diseases (PCDs), such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). Emerging evidence suggests the gut microbiota plays a role in their pathogenesis, though the influences of specific bacteria on disease-associated proteins remain elusive. Here, we reveal the effects of 229 human bacterial isolates on the aggregation and toxicity of Aß1-42, α-synuclein, and polyglutamine tracts in Caenorhabditis elegans expressing these culprit proteins. Our findings demonstrate that bacterial effects on host protein aggregation are consistent across different culprit proteins, suggesting that microbes affect protein stability by modulating host proteostasis rather than selectively targeting disease-associated proteins. Furthermore, we found that feeding C. elegans proteoprotective Prevotella corporis activates the heat shock response, revealing an unexpected discovery of a microbial influence on host proteostasis. Insight into how individual bacteria affect PCD proteins could open new strategies for prevention and treatment by altering the abundance of microbes.

PanKA: Leveraging population pangenome to predict antibiotic resistance.

Machine learning has the potential to be a powerful tool in the fight against antimicrobial resistance (AMR), a critical global health issue. Machine learning can identify resistance mechanisms from DNA sequence data without prior knowledge. The first step in building a machine learning model is a feature extraction from sequencing data. Traditional methods like single nucleotide polymorphism (SNP) calling and k-mer counting yield numerous, often redundant features, complicating prediction and analysis. In this paper, we propose PanKA, a method using the pangenome to extract a concise set of relevant features for predicting AMR. PanKA not only enables fast model training and prediction but also improves accuracy. Applied to the Escherichia coli and Klebsiella pneumoniae bacterial species, our model is more accurate than conventional and state-of-the-art methods in predicting AMR.

Shibasaburo Kitasato (1853-1931): Pioneer of Japanese Medicine and Global Immunology Innovator.

Shibasaburo Kitasato (1853-1931), a pivotal figure in modern Japanese medicine, made groundbreaking contributions to bacteriology and immunology. His achievements include pure cultivation of the tetanus bacillus and the development of serum therapy, which continue to influence modern immunology and vaccination strategies. Kitasato established the Institute for Infectious Diseases in Japan, the Kitasato Institute, played a crucial role in establishing the Keio University School of Medicine, and served as the first president of the Japan Medical Association. His international collaboration with Robert Koch and Emil von Behring elevated Japan's status in global medical research. Kitasato's research philosophy emphasizes clinical applicability and passionate pursuit of effective topics, inspiring the generation of prominent Japanese medical researchers. This study highlights Kitasato's life, work, and enduring impact on medical research, education, and healthcare administration. Kitasato's legacy, commemorated on the new 1000-yen banknote in 2024, continues to serve as an inspiration for contemporary medical professionals worldwide.

Spatiotemporal patterns and socioeconomic determinants of pulmonary tuberculosis in Dongguan city, China, during 2011-2020: an ecological study.

OBJECTIVE: Pulmonary tuberculosis (PTB) is a critical challenge worldwide, particularly in China. This study aimed to explore the spatiotemporal transmission patterns and socioeconomic factors of PTB in Dongguan city, China. METHODS/DESIGN: An ecological study based on the reported new PTB cases between 2011 and 2020 was conducted in Dongguan city, China. The spatiotemporal analysis methods were used to explore the long-term trend, spatiotemporal transmission pattern and socioeconomic factors of PTB. MAIN OUTCOME MEASURES: The number of new PTB cases. PARTICIPANTS: We collected 35 756 new PTB cases, including 23 572 males and 12 184 females. RESULTS: The seasonal-trend decomposition indicated a significant downward trend for PTB with a significant peak in 2017 and 2018, and local spatial autocorrelation showed more and more high-high clusters in the central and north-central towns with high incidence. The multivariate spatial time series analysis revealed that the endemic component had a leading role in driving PTB transmission, with a high total effect value being 189.40 (95% CI: 171.65-207.15). A Bayesian spatiotemporal model revealed that PTB incidence is positively associated with the agricultural population ratio (relative risk (RR) =1.074), gender ratio (RR=1.104) and the number of beds in medical institutions (RR=1.028). CONCLUSIONS: These findings revealed potential spatiotemporal variability and spatial aggregation of PTB, so targeted preventive strategies should be made in different towns based on spatiotemporal transmission patterns and risk factors.

A novel pan-proteome array for high-throughput profiling of the humoral response to Treponema pallidum.

Given the resurgence of syphilis, research endeavors to improve current assays for serological diagnosis and management of this disease are a priority. A proteome-scale platform for high-throughput profiling of the humoral response to Treponema pallidum (T. pallidum) proteins during infection could identify antigens suitable to ameliorate the performance and capabilities of treponemal tests for syphilis. Additionally, because infection-induced immunity is partially protective, profiling the response to T. pallidum outer membrane proteins (OMPs) could help select vaccine candidates. Therefore, we developed a pan-proteome array (PPA) based on the Nichols and SS14 strain complete proteomes and used it to define the immunoglobulin M (IgM) and IgG humoral response to T. pallidum proteins in sera collected longitudinally from long-term infected rabbits and from rabbits that were infected, treated, and re-infected. We identified antigens that could facilitate early diagnosis and immunity to a core set of OMP that could explain protection upon reinfection.

Combining short- and long-read sequencing unveils geographically structured diversity in Borrelia miyamotoi.

Borrelia miyamotoi is an emerging Ixodes tick-borne human pathogen in the Northern hemisphere. The aim of the current study was to compare whole genome sequences of B. miyamotoi isolates from different continents. Using a combination of Illumina and PacBio platforms and a novel genome assembly and plasmid typing pipeline, we reveal that the 21 sequenced B. miyamotoi isolates and publically available B. miyamotoi genomes from North America, Asia, and Europe form genetically distinct populations and cluster according to their geographical origin, where distinct Ixodes species are endemic. We identified 20 linear and 17 circular plasmid types and the presence of specific plasmids for isolates originating from different continents. Linear plasmids lp12, lp23, lp41, and lp72 were core plasmids found in all isolates, with lp41 consistently containing the vmp expression site. Our data provide insights into the genetic basis of vector competence, virulence, and pathogenesis of B. miyamotoi.

Impact of sample refrigeration and freezing on the bacteriological counts of different bedding materials for dairy cows.

BACKGROUND: Different organic and inorganic bedding materials can be used in dairy farms. Among organic materials, there is an increasing interest in alternative substrates based on recycled manure solids (RMS). Microbiological analyses are crucial to monitor the microbial load and evaluate the presence of pathogens impacting animal welfare and health. However, logistic factors may hamper the possibility of immediately sending fresh samples to the laboratory, requiring storage in cooled conditions before analysis. METHODS: We assessed the impact of sample refrigeration and freezing of different organic and inorganic bedding substrates including separated raw manure solids (SRMS), anaerobically digested manure solids (ADMS), and new sand (NS), on the total bacterial count (TBC) and on different microbial classes. RESULTS: The TBC was higher in fresh NS and ADMS than in refrigerated and frozen samples of the same substrates; in addition, the TBC of ADMS was higher in refrigerated than frozen samples. The TBC of SRMS did not change significantly with refrigeration and freezing. Freezing reduced the total Gram-negative bacterial count more than refrigeration in all substrates. In fresh NS, Gram-negatives were higher than in both refrigerated and frozen NS. Escherichia coli counts were significantly lower in frozen than in refrigerated SRMS. However, both refrigeration and freezing of ADMS resulted in no E. coli growth. The coliform counts were also lower in frozen than refrigerated NS and SRMS. Frozen NS and ADMS showed lower counts compared to refrigeration for Gram-negative bacteria other than E. coli and coliforms. On the other hand, cold storage did not significantly impact the streptococci and streptococcus-like organisms (SSLO) count of all evaluated bedding substrates. CONCLUSION: Refrigeration and freezing affect the bacteriological results of bedding substrates, with freezing generally leading to lower counts than refrigeration. Whenever possible, preference should be given to analyzing fresh bedding samples, however, when necessary, refrigeration would be recommended over freezing, while acknowledging that the measured bacterial load might underestimate the actual microbial content.

Louis Pasteur: A Legacy Unmasked.

Louis Pasteur is perhaps the most globally recognized French scientist. His groundbreaking discoveries in molecular chirality and advancements in fermentation greatly benefited brewers and winemakers. Pasteur introduced the process of pasteurization to sterilize wines and significantly contributed to the development of germ theory, which made Joseph Lister's antiseptic surgical techniques possible. Despite initially disproving Antoine Béchamp's theory that silkworm disease was caused by a microbial infection, Pasteur tackled this issue effectively. Building on the work of Henri Toussaint and Pierre Victor Galtier, he developed vaccines for pig erysipelas, chicken cholera, anthrax, and rabies. Pasteur also coined the term "vaccination," which Richard Dunning had used before Edward Jenner expanded upon it. Although Robert Koch criticized Pasteur's vaccination methods as ambiguous, historians have clarified many of the myths surrounding Pasteur. This review explores Pasteur's career, his undeniable achievements, and the realities behind the legendary figure who strove to make a significant impact on science and medicine.

Protocol for a clinically annotated biorepository of samples from Australian immune-compromised patients to investigate the host-microbiome interaction.

INTRODUCTION: The human gut microbiota has the potential to modulate the outcomes of several human diseases. This effect is likely to be mediated through interaction with the host immune system. This protocol details the establishment of a biorepository of clinically annotated samples, which we will use to explore correlations between the gut microbiota and the immune system of immune-compromised patients. We aim to identify microbiome-related risk factors for adverse outcomes. METHODS AND ANALYSES: This is a protocol for the development of a biorepository of clinically annotated samples collected prospectively across three centres in Melbourne, Australia. Participants will be recruited across the following clinical streams: (1) acute leukaemia and allogeneic stem cell transplant; (2) end-stage liver disease and liver transplant; (3) patients receiving any cancer immunotherapies (eg, chimeric antigen receptor therapy); (4) deceased organ donors and (5) healthy adult controls. Participants will be asked to provide paired peripheral blood and microbiota samples (stool and saliva) at either (1) single time point for healthy controls and deceased organ donors or (2) longitudinally over multiple prespecified or event-driven time points for the remaining cohorts. Sampling of fluid from bronchoalveolar lavage and colonoscopy or biopsy of tissues undertaken during routine care will also be performed. ETHICS AND DISSEMINATION: Ethical approval has been obtained from the relevant local ethics committee (The Royal Melbourne Hospital Human Research Ethics Committee). The results of this study will be disseminated by various scientific platforms including social media, international presentations and publication in peer-reviewed journals. TRIAL REGISTRATION NUMBER: ACTRN12623001105639. Date registered 20 October 2023.

Bacterial pore-forming toxin pneumolysin drives pathogenicity through host extracellular vesicles released during infection.

Streptococcus pneumoniae is a global priority respiratory pathogen that kills over a million people annually. The pore-forming cytotoxin, pneumolysin (PLY) is a major virulence factor. Here, we found that recombinant PLY as well as wild-type pneumococcal strains, but not the isogenic PLY mutant, upregulated the shedding of extracellular vesicles (EVs) harboring membrane-bound toxin from human THP-1 monocytes. PLY-EVs induced cytotoxicity and hemolysis dose-dependently upon internalization by recipient monocyte-derived dendritic cells. Proteomics analysis revealed that PLY-EVs are selectively enriched in key inflammatory host proteins such as IFI16, NLRC4, PTX3, and MMP9. EVs shed from PLY-challenged or infected cells induced dendritic cell maturation and primed them to infection. In vivo, zebrafish administered with PLY-EVs showed pericardial edema and mortality. Adoptive transfer of bronchoalveolar-lavage-derived EVs from infected mice to healthy recipients induced lung damage and inflammation in a PLY-dependent manner. Our findings identify that host EVs released during infection mediate pneumococcal pathogenesis.

Average Nucleotide Identity and Digital DNA-DNA Hybridization Analysis Following PromethION Nanopore-Based Whole Genome Sequencing Allows for Accurate Prokaryotic Typing.

Whole-genome sequencing (WGS) is revolutionizing clinical bacteriology. However, bacterial typing remains investigated by reference techniques with inherent limitations. This stresses the need for alternative methods providing robust and accurate sequence type (ST) classification. This study optimized and evaluated a GridION nanopore sequencing protocol, adapted for the PromethION platform. Forty-eight Escherichia coli clinical isolates with diverse STs were sequenced to assess two alternative typing methods and resistance profiling applications. Multi-locus sequence typing (MLST) was used as the reference typing method. Genomic relatedness was assessed using Average Nucleotide Identity (ANI) and digital DNA-DNA Hybridization (DDH), and cut-offs for discriminative strain resolution were evaluated. WGS-based antibiotic resistance prediction was compared to reference Minimum Inhibitory Concentration (MIC) assays. We found ANI and DDH cut-offs of 99.3% and 94.1%, respectively, which correlated well with MLST classifications and demonstrated potentially higher discriminative resolution than MLST. WGS-based antibiotic resistance prediction showed categorical agreements of ≥ 93% with MIC assays for amoxicillin, ceftazidime, amikacin, tobramycin, and trimethoprim-sulfamethoxazole. Performance was suboptimal (68.8-81.3%) for amoxicillin-clavulanic acid, cefepime, aztreonam, and ciprofloxacin. A minimal sequencing coverage of 12× was required to maintain essential genomic features and typing accuracy. Our protocol allows the integration of PromethION technology in clinical laboratories, with ANI and DDH proving to be accurate and robust alternative typing methods, potentially offering superior resolution. WGS-based antibiotic resistance prediction holds promise for specific antibiotic classes.

A Situation Analysis of the Capacity of Laboratories in Faith-Based Hospitals in Zambia to Conduct Surveillance of Antimicrobial Resistance: Opportunities to Improve Diagnostic Stewardship.

Antimicrobial resistance (AMR) is a public health problem exacerbated by the overuse and misuse of antibiotics and the inadequate capacity of laboratories to conduct AMR surveillance. This study assessed the capacity of laboratories in seven faith-based hospitals to conduct AMR testing and surveillance in Zambia. This multi-facility, cross-sectional exploratory study was conducted from February 2024 to April 2024. We collected and analysed data using the self-scoring Laboratory Assessment of Antibiotic Resistance Testing Capacity (LAARC) tool. This study found an average score of 39%, indicating a low capacity of laboratories to conduct AMR surveillance. The highest capacity score was 47%, while the lowest was 25%. Only one hospital had a full capacity (100%) to utilise a laboratory information system (LIS). Three hospitals had a satisfactory capacity to perform data management with scores of 83%, 85%, and 95%. Only one hospital had a full capacity (100%) to process specimens, and only one hospital had good safety requirements for a microbiology laboratory, with a score of 89%. This study demonstrates that all the assessed hospitals had a low capacity to conduct AMR surveillance, which could affect diagnostic stewardship. Therefore, there is an urgent need to strengthen the microbiology capacity of laboratories to enhance AMR surveillance in Zambia.

TC-14, a cathelicidin-derived antimicrobial peptide with broad-spectrum antibacterial activity and high safety profile.

Cathelicidins, a major class of antimicrobial peptides (AMPs), hold considerable potential for antimicrobial drug development. In the present study, we identified a novel cathelicidin AMP (TC-33) derived from the Chinese tree shrew. Despite TC-33 demonstrating weak antimicrobial activity, the novel peptide TC-14, developed based on its active region, exhibited a 432-fold increase in antimicrobial activity over the parent peptide. Structural analysis revealed that TC-14 adopted an amphipathic α-helical conformation. The bactericidal mechanism of TC-14 involved targeting and disrupting the bacterial membrane, leading to rapid membrane permeabilization and rupture. Furthermore, TC-14 exhibited a high-safety profile, as evidenced by the absence of cytotoxic and hemolytic activities, as well as high biocompatibility and safety in vivo. Of note, its potent antimicrobial activity provided significant protection in a murine model of skin infection. Overall, this study presents TC-14 as a promising drug candidate for antimicrobial drug development.

Surveillance of antibiotics use in inpatients at Benjamin Mkapa Zonal Referral Hospital in Dodoma, Tanzania: a point prevalence survey.

OBJECTIVE: To assess antibiotics prescribing and use patterns for inpatients at Benjamin Mkapa Zonal Referral Hospital (BMH) using the WHO-Point Prevalence Survey (WHO-PPS). DESIGN: A cross-sectional survey. SETTING: The Benjamin Mkapa Zonal Referral Hospital, Dodoma, Tanzania. PARTICIPANTS: Inpatient prescriptions, regardless of whether antibiotics were prescribed (n=286) on the day of PPS. OUTCOME MEASURES: Our study analysed the prevalence of antibiotic use at BMH for inpatients, the type of antibiotics used, the indications for use and the proportion of oral and parenteral antibiotics. We also assessed prescription-prescribed antibiotics after a positive antimicrobial susceptibility testing (AST) result. RESULTS: A survey was conducted on 286 prescriptions, which revealed that 30.07% of them included antibiotics. On average, each prescription contained at least 1.6 antibiotics. All prescriptions that included antibiotics were written in generic names, and 77.91% (67/86) of them followed the Standard Treatment Guidelines. Of the prescriptions that included antibiotics, 58.14% (50/86) had a single antibiotic, 20.93% (18/86) had parenteral antibiotics and 79.07% (68/86) had oral antibiotics. Based on AWaRe's (Access, Watch and Reserve) categorisation of antibiotics, 50% (8/16) were in the Access group, 31.25% (5/16) were in the Watch group, 12.50% (2/16) were in the Reserve group and 6.25% (1/16) were not recommended antimicrobial combinations. Out of 86 prescriptions included antibiotics, only 4.65% showed positive culture growth. However, antibiotics were still prescribed in 29.07% of prescriptions where there was no growth of bacteria, and in 66.28% of prescriptions, antibiotics were prescribed empirically without any requesting of bacteria culture and AST. CONCLUSION: BMH has reduced inpatient Antibiotic Use by half compared with the 2019 WHO-PPS. Adherence to National Treatment Guidelines is suboptimal. Clinicians should use AST results to guide antibiotic prescribing.

TetR-like regulator BP1026B_II1561 controls aromatic amino acid biosynthesis and intracellular pathogenesis in Burkholderia pseudomallei.

Burkholderia pseudomallei (Bp) causes the tropical disease melioidosis that afflicts an estimated 165,000 people each year. Bp is a facultative intracellular pathogen that transits through distinct intracellular stages including attachment to host cells, invasion through the endocytic pathway, escape from the endosome, replication in the cytoplasm, generation of protrusions towards neighboring cells, and host cell fusion allowing Bp infection to spread without exiting the intracellular environment. We have identified a TetR-like transcriptional regulator, BP1026B_II1561, that is up-regulated during the late stages of infection as Bp protrudes toward neighboring cells. We have characterized BP1026B_II1561 and determined that it has a role in pathogenesis. A deletional mutant of BP1026B_II1561 is attenuated in RAW264.7 macrophage and BALB/c mouse models of infection. Using RNA-seq, we found that BP1026B_II1561 controls secondary metabolite biosynthesis, fatty acid degradation, and propanoate metabolism. In addition, we identified that BP1026B_II1561 directly controls expression of an outer membrane porin and genes in the shikimate biosynthetic pathway using ChIP-seq. Transposon mutants of genes within the BP1026B_II1561 regulon show defects during intracellular replication in RAW264.7 cells confirming the role of this transcriptional regulator and the pathways it controls in pathogenesis. BP1026B_II1561 also up-regulates the majority of the enzymes in shikimate and tryptophan biosynthetic pathways, suggesting their importance for Bp physiology. To investigate this, we tested fluorinated analogs of anthranilate and tryptophan, intermediates and products of the shikimate and tryptophan biosynthetic pathways, respectively, and showed inhibition of Bp growth at nanomolar concentrations. The expression of these pathways by BP1026b_II1561 and during intracellular infection combined with the inhibition of Bp growth by fluorotryptophan/anthranilate highlights these pathways as potential targets for therapeutic intervention against melioidosis. In the present study, we have identified BP1026B_II1561 as a critical transcriptional regulator for Bp pathogenesis and partially characterized its role during host cell infection.

Chronic dacryocystitis: An insight into bacteriology and antimicrobial sensitivity pattern.

CONTEXT: Adequate management of chronic dacryocystitis is an essential prerequisite before any intraocular surgery owing to a grave risk of endophthalmitis. The knowledge of bacteriology of chronic dacryocystitis would accentuate the choice of effective antimicrobial agents and thus help in reducing the irrational use of antimicrobial agents and subsequent development of drug resistance. AIMS: We aimed to identify the causative bacterial flora and study the antimicrobial sensitivity and resistance pattern in cases of chronic dacryocystitis. SETTINGS AND DESIGN: This was a cross-sectional observational study. SUBJECTS AND METHODS: Conjunctival swabs were obtained from both eyes from 102 patients with clinical evidence of chronic dacryocystitis. Specimens for microbiological analysis were obtained, either from the conjunctival cul-de-sac and everted puncta by applying pressure over the lacrimal sac area or from the refluxing material after irrigating the lacrimal sac with sterile saline. The specimens were sent for culture and sensitivity in the department of microbiology. Ethical approvals were duly obtained. STATISTICAL ANALYSIS USED: Percentage assessment was used for statistical analysis. RESULTS: The cultures showed the presence of Staphylococcus aureus in 50% of bacterial isolates obtained from the involved eyes, followed by coagulase-negative Staphylococcus in 11.53% of isolates and Enterococcus also in 11.53% of isolates. It was observed that cefoxitin was the most sensitive antibiotic against Gram-positive organisms, followed by vancomycin and clindamycin, whereas maximum resistance was seen for penicillin and ofloxacin. For Gram-negative organisms, imipenem was found to be most sensitive, followed by gentamicin and co-amoxiclav, whereas maximum resistance was seen for ciprofloxacin. CONCLUSIONS: It was concluded that Gram-positive bacteria predominantly S. aureus was the most commonly isolated bacteria in cases of chronic dacryocystitis as compared to Gram-negative bacteria and cefoxitin was found to be the overall most effective antibiotic for Gram-positive bacteria.

Microbial Composition of Extracted Dental Alveoli in Dogs with Advanced Periodontitis.

Periodontitis is a serious gum infection that damages the soft tissue and destroys the bone supporting the teeth. The aim of the study was to investigate the microbiota using traditional microbiology plating and metagenomic sequencing of extracted tooth alveoli in dogs with severe periodontitis. Isolation of culturable microorganisms was performed as part of bacteriological testing to provide bacteriological diagnosis to veterinary surgeons. Metagenomic sequencing was performed using shotgun sequencing on the Illumina HiSeq system platform. The most prevalent species at sites of periodontal infection detected by metagenomic sequencing were Porphyromonas gulae, Prevotella spp., Tannerella forsythia, Porphyromonas crevioricanis, Porphyromonas cangingivalis, and Bacteroides heparinolyticus. Pasteurella, Streptococcus, and Neisseria were the most frequently isolated culturable bacteria from infected sites detected by traditional microbiologic methods. Metagenomic data revealed that these three genera accounted for only 1.6% of all microbiota at the sites of infection. Antimicrobial resistance patterns of the isolated bacteria included resistance to ampicillin, doxycycline, sulfamethoxazole-trimethoprim, ciprofloxacin, colistin, cefotaxime, and chloramphenicol. Antimicrobial-resistant genes detected using shotgun sequencing also showed resistance to aminoglycosides and macrolides. Dogs with periodontal infections carry bacteria that can cause bite infections in humans as well as multi-resistant isolates. Therefore, treatment and prophylaxis or periodontal disease of dogs is important from a One Health perspective.

Capabilities of GPT-4o and Gemini 1.5 Pro in Gram stain and bacterial shape identification.

Aim: Assessing the visual accuracy of two large language models (LLMs) in microbial classification. Materials & methods: GPT-4o and Gemini 1.5 Pro were evaluated in distinguishing Gram-positive from Gram-negative bacteria and classifying them as cocci or bacilli using 80 Gram stain images from a labeled database. Results: GPT-4o achieved 100% accuracy in identifying simultaneously Gram stain and shape for Clostridium perfringens, Pseudomonas aeruginosa and Staphylococcus aureus. Gemini 1.5 Pro showed more variability for similar bacteria (45, 100 and 95%, respectively). Both LLMs failed to identify both Gram stain and bacterial shape for Neisseria gonorrhoeae. Cumulative accuracy plots indicated that GPT-4o consistently performed equally or better in every identification, except for Neisseria gonorrhoeae's shape. Conclusion: These results suggest that these LLMs in their unprimed state are not ready to be implemented in clinical practice and highlight the need for more research with larger datasets to improve LLMs' effectiveness in clinical microbiology.

This study looked at how well large language models (LLMs) could identify different types of bacteria using images, without having any specific training in this area beforehand.We tested two LLMs with image analysis capabilities, GPT-4o and Gemini 1.5 Pro. These models were asked to determine whether bacteria were Gram-positive or Gram-negative and whether they were round (cocci) or rod-shaped (bacilli). We used 80 images of four stained bacteria from a labeled database as a reference for this test.GPT-4o was more accurate in identifying both the Gram stain and shape of the bacteria compared with Gemini 1.5 Pro. GPT-4o had excellent accuracy in correctly classifying the Gram stain and bacterial shape of Clostridium perfringens, Pseudomonas aeruginosa and Staphylococcus aureus. Gemini 1.5 Pro had mixed results for these bacteria. However, both models struggled with Neisseria gonorrhoeae, failing to correctly identify its Gram stain and shape.The study shows that while these LLMs have potential, they are not ready to be implemented in clinical practice. More research and larger datasets are needed to improve their accuracy in clinical microbiology.

PPARdelta: A key modulator in the pathogenesis of diabetes mellitus and Mycobacterium tuberculosis co-morbidity.

The interplay between lipid metabolism and immune response in macrophages plays a pivotal role in various infectious diseases, notably tuberculosis (TB). Herein, we illuminate the modulatory effect of heat-killed Mycobacterium tuberculosis (HKMT) on macrophage lipid metabolism and its implications on the inflammatory cascade. Our findings demonstrate that HKMT potently activates the lipid scavenger receptor, CD36, instigating lipid accumulation. While CD36 inhibition mitigated lipid increase, it unexpectedly exacerbated the inflammatory response. Intriguingly, this paradoxical effect was linked to an upregulation of PPARδ. Functional analyses employing PPARδ modulation revealed its central role in regulating both lipid dynamics and inflammation, suggesting it as a potential therapeutic target. Moreover, primary monocytic cells from diabetic individuals, a demographic at amplified risk of TB, exhibited heightened PPARδ expression and inflammation, further underscoring its pathological relevance. Targeting PPARδ in these cells effectively dampened the inflammatory response, offering a promising therapeutic avenue against TB.