Search Results (359)

Background/Objectives: Listeria monocytogenes is a foodborne pathogen of major public health concern due to its ability to invade host cells and cause severe illness. This study aimed to develop and validate a multi-tiered screening pipeline to identify Bacillus strains with probiotic potential against L. monocytogenes. Methods: A total of 26 Bacillus isolates were screened for antimicrobial activity, gastrointestinal resilience, and host cell adhesion. A fluorescence-based infection assay using mCherry-expressing HCT 116 cells was used to assess cytoprotection against L. monocytogenes NCTC 7973. Eight strains significantly improved host cell viability and were validated by quantification of intracellular CFU. Two top candidates were tested in a murine model of listeriosis. The genome of the lead strain was sequenced to evaluate safety and biosynthetic potential. Results: B. subtilis CECT 8266 completely inhibited intracellular replication of L. monocytogenes in HCT 116 cells, reducing bacterial recovery to undetectable levels. In vivo, it decreased splenic bacterial burden by approximately 6-fold. Genomic analysis revealed eight bacteriocin biosynthetic clusters and silent antibiotic resistance genes within predicted genomic islands, as determined by CARD and Alien Hunter analysis. The strain also demonstrated bile and acid tolerance, as well as strong adhesion to epithelial cells. Conclusions: The proposed pipeline enables efficient identification of probiotic Bacillus strains with intracellular protective activity. B. subtilis CECT 8266 is a promising candidate for translational applications in food safety or health due to its efficacy, resilience, and safety profile. Full article

Avian influenza viruses (AIVs) pose significant risks to occupational populations engaged in poultry farming, livestock handling, and live poultry market operations due to frequent exposure to infected animals and contaminated environments. This review synthesizes evidence on AIV exposure patterns and risk factors through a comprehensive analysis of viral characteristics, host dynamics, environmental influences, and human behaviors. The main routes of transmission include direct animal contact, respiratory contact during slaughter/milking, and environmental contamination (aerosols, raw milk, shared equipment). Risks increase as the virus adapts between species, survives longer in cold/wet conditions, and spreads through wild bird migration (long-distance transmission) and live bird trade (local transmission). Recommended control measures include integrated animal–human–environment surveillance, stringent biosecurity measures, vaccination, and education. These findings underscore the urgent need for global ‘One Health’ collaboration to assess risk and implement preventive measures against potentially pandemic strains of influenza A viruses, especially in light of undetected mild/asymptomatic cases and incomplete knowledge of viral evolution. Full article

Several species of Fusarium are reported to infect inflorescences of high-THC-containing cannabis (Cannabis sativa L.) plants grown in greenhouses in Canada. These include F. graminearum, F. sporotrichiodes, F. proliferatum, and, to a lesser extent, F. oxysporum and F. solani. The greatest concern surrounding the infection of cannabis by these Fusarium species, which cause symptoms of bud rot, is the potential for the accumulation of mycotoxins that may go undetected. In the present study, both naturally infected and artificially infected inflorescence tissues were tested for the presence of fungal-derived toxins using HPLC-MS/MS analysis. Naturally infected cannabis tissues were confirmed to be infected by both F. avenaceum and F. graminearum using PCR. Pure cultures of these two species and F. sporotrichiodes were inoculated onto detached inflorescences of two cannabis genotypes, and after 7 days, they were dried and assayed for mycotoxin presence. In these assays, all Fusarium species grew prolifically over the tissue surface. Tissues infected by F. graminearum contained 3-acetyl DON, DON, and zearalenone in the ranges of 0.13–0.40, 1.18–1.91, and 31.8 to 56.2 μg/g, respectively, depending on the cannabis genotype. In F. sporotrichiodes-infected samples, HT2 and T2 mycotoxins were present at 13.9 and 10.9 μg/g in one genotype and were lower in the other. In F. avenaceum-inoculated tissues, the mycotoxins enniatin A, enniatin A1, enniatin B, and enniatin B1 were produced at varying concentrations, depending on the isolate and cannabis genotype. Unexpectedly, these tissues also contained detectable levels of 3-acetyl DON, DON, and zearalenone, which was attributed to apre-existing natural infection by F. graminearum that was confirmed by RT-qPCR. Beauvericin was detected in tissues infected by F. avenaceum and F. sporotrichiodes, but not by F. graminearum. Naturally infected, dried inflorescences from which F. avenaceum was recovered contained beauvericin, enniatin A1, enniatin B, and enniatin B1 as expected. Uninoculated cannabis inflorescences were free of mycotoxins except for culmorin at 0.348 μg/g, reflecting pre-existing infection by F. graminearum. The mycotoxin levels were markedly different between the two cannabis genotypes, despite comparable mycelial colonization. Tall fescue plants growing in the vicinity of the greenhouse were shown to harbor F. avenaceum and F. graminearum, suggesting a likely external source of inoculum. Isolates of both species from tall fescue produced mycotoxins when inoculated onto cannabis inflorescences. These findings demonstrate that infection by F. graminearum and F. avenaceum, either from artificial inoculation or natural inoculum originating from tall fescue plants, can lead to mycotoxin accumulation in cannabis inflorescences. However, extensive mycelial colonization following prolonged incubation of infected tissues under high humidity conditions is required. Inoculations with Penicillium citrinum and Aspergillus ochraceus under these conditions produced no detectable mycotoxins. The mycotoxins alternariol and tentoxin were detected in several inflorescence samples, likely as a result of natural infection by Alternaria spp. Fusarium avenaceum is reported to infect cannabis inflorescences for the first time and produces mycotoxins in diseased tissues. Full article

Protocol biopsies are a fundamental component in the management of kidney transplant recipients, offering critical insights into graft health by detecting subclinical pathological changes undetectable through routine clinical and laboratory assessments. Conducted at predetermined intervals, these biopsies enable early identification of subclinical rejection, chronic allograft nephropathy, drug-induced toxicities, viral infections such as BK polyomavirus nephropathy, and recurrence of primary glomerular diseases. Early detection facilitates timely therapeutic interventions, including immunosuppressive regimen adjustments, which are pivotal in preserving graft function and improving long-term outcomes. While the optimal timing and frequency of protocol biopsies vary, early post-transplant biopsies within the first year are widely advocated. High-risk groups, including ABO- and HLA-incompatible recipients and those with recurrent primary nephropathies, particularly benefit from surveillance biopsies. Despite the invasive nature and associated risks of biopsy procedures, most experts agree that the benefits outweigh the risks in selected populations. However, the role of routine protocol biopsies in low-risk patients remains debated due to unclear long-term outcome improvements and resource considerations. Retrospective observational studies have demonstrated the ability of protocol biopsies to detect subclinical pathological changes such as rejection, drug toxicity, viral infections, and recurrent diseases before clinical or laboratory abnormalities appear. These studies also highlight the impact of biopsy-guided interventions on graft survival and management in high-risk groups (e.g., HLA- and ABO-incompatible recipients, and patients at risk for disease recurrence). Furthermore, randomized controlled trials provide higher-level evidence showing that protocol biopsy-guided interventions improve graft function, reflected by better serum creatinine levels and glomerular filtration rates, compared to indicated biopsies alone. They also emphasize the importance of both early and late surveillance biopsies for predicting long-term outcomes. Expert opinion and consensus acknowledge the benefits of protocol biopsies for early detection and tailored management but also highlight ongoing debates regarding their routine use in low-risk patients due to risks, costs, and resource considerations. Overall, protocol biopsies represent a valuable tool for personalized graft monitoring and management, aiding in early detection of complications, guiding immunosuppressive therapy, and enhancing graft longevity. Further multicenter randomized trials are needed to refine guidelines and optimize their clinical utility. Full article

Candida auris is an emerging multidrug-resistant fungal pathogen with a high affinity for skin colonization and significant potential for nosocomial transmission. This study aimed to develop and evaluate chitosan-based hydrogels loaded with nystatin and propolis as a topical antifungal strategy for skin decolonization of C. auris. The formulations were selected based on our previous results and optimized for cutaneous application. The internal structure of the hydrogels was investigated by polarized light microscopy, confirming the amorphous nature of propolis and the partial dispersion of nystatin. The antifungal activity was assessed against ten fluconazole-resistant C. auris strains. The CS-NYS-PRO1 formulation demonstrated the highest antifungal performance in the agar test, also reducing viable cell counts to undetectable levels within 6 h. Time–kill assays and SEM imaging confirmed the rapid fungicidal effect and revealed severe membrane disruption and cytoplasmic leakage. Molecular docking analyses indicated the strong binding of nystatin to both sterol 14α-demethylase (CYP51) and dihydrofolate reductase (DHFR) from C. auris, suggesting complementary membrane and intracellular mechanisms of action. These findings support the use of such hydrogels as a local, non-invasive, and biocompatible strategy for managing C. auris colonization, with promising implications for clinical use in infection control and the prevention of skin-mediated transmission in healthcare settings. Full article

Peripheral blood leukocytes are able to migrate to the inflamed tissue, and to engulf and kill invading microbes. This requires rapid modifications of cell morphology and volume through fast movements of osmotic water into or out of the cell. In this process, membrane water channels, aquaporins (AQPs), are critical for cell shape changes as AQP-mediated water movement indirectly affects the cell cytoskeleton and, thereby, the signaling cascades. Recent studies have shown that the deletion or gating of two immune cell AQPs, AQP3 and AQP9, impairs inflammation and improves survival in microbial sepsis. Here, we assessed the expression and distribution of AQP3 and AQP9 in human leukocytes and investigated their involvement in the phagocytosis and killing of the Gram-negative pathogenic bacterium Klebsiella pneumoniae, and their role in lipopolysaccharide (LPS)-induced cell migration. By RT-qPCR, AQP3 mRNA was found in peripheral blood mononuclear cells (PBMCs) but it was undetectable in polymorphonuclear white blood cells (PMNs). AQP9 was found both in PBMCs and PMNs, particularly in neutrophil granulocytes. Immunofluorescence confirmed the AQP3 expression in monocytes and, to a lesser degree, in lymphocytes. AQP9 was expressed both in PBMCs and neutrophils. Specific inhibitors of AQP3 (DFP00173) and AQP9 (HTS13286 and RG100204) were used for bacterial phagocytosis and killing studies. No apparent involvement of individually blocked AQP3 or AQP9 was observed in the phagocytosis of K. pneumoniae by neutrophils or monocytes after 10, 30, or 60 min of bacterial infection. A significant impairment in the phagocytic capacity of monocytes but not neutrophils was observed only when both AQPs were inhibited simultaneously and when the infection lasted for 60 min. No impairment in bacterial clearance was found when AQP3 and AQP9 were individually or simultaneously blocked. PBMC migration was significantly impaired after exposure to the AQP9 blocker RG100204 in the presence or absence of LPS. The AQP3 inhibitor DFP00173 reduced PBMC migration only under LPS exposure. Neutrophil migration was considerably reduced in the presence of RG100204 regardless of whether there was an LPS challenge or not. Taken together, these results indicate critical but distinct involvements for AQP3 and AQP9 in leukocyte motility, while no roles are played in bacterial killing. Further studies are needed in order to understand the precise ways in which these two AQPs intervene during bacterial infections. Full article

(1) Background: Hepatitis C virus (HCV) infection poses a significant health burden, particularly in Mongolia, where the HCV prevalence is notably high. This study evaluates the long-term outcomes of HCV treatment with ledipasvir/sofosbuvir, focusing on mortality, viral relapse, and hepatocellular carcinoma (HCC) development. (2) Methods: This prospective, longitudinal cohort study initially enrolled patients with chronic HCV in Mongolia between 2016 and 2017, focusing on those who completed the five-year follow-up (n = 303). The study measured long-term mortality, HCC development, and viral relapse, employing non-invasive methods to assess liver fibrosis and liver function. (3) Results: At the outset, 98.2% of the patients achieved undetectable HCV RNA levels. Over five years, 6.27% experienced viral relapse and 3.30% developed hepatocellular carcinoma (HCC), with a mortality rate of 5.94%. In a multivariable analysis, the significant predictors for HCC occurrence included age (OR = 1.081, 95% CI = 1.021–1.145), liver cirrhosis (OR = 5.866, 95% CI = 1.672–22.577), and GGT level (OR = 1.011, 95% CI = 1.004–1.018). The independent predictors of mortality included age (OR = 1.083, 95% CI = 1.024–1.147), liver cirrhosis (OR = 6.529, 95% CI = 1.913–22.281), and GGT (OR = 1.011, 95% CI = 1.004–1.017). (4) Conclusions: This study demonstrates that ledipasvir/sofosbuvir effectively suppresses HCV initially and maintains low viral relapse rates over the long term. However, it emphasizes the need for continued management to reduce the long-term risk of HCC and mortality, especially in patients with severe liver fibrosis or cirrhosis. Full article

Arboviruses transmitted by Aedes aegypti pose a significant challenge in Ecuador, as they are persistent, emerging, and re-emerging. During the SARS-CoV-2 pandemic, these diseases were temporarily overshadowed. This study aimed to detect and identify arbovirus species in mosquitoes collected from two communities in Manabí province—Caja Fuego (rural) and San Gregorio (marginal urban). A total of 468 mosquitoes were collected—385 from Caja Fuego and 83 from San Gregorio—and grouped into 72 pools. Samples were transported to CISeAL under proper biosafety protocols, homogenized, and analyzed using End-Point PCR, RT-PCR, and Sanger sequencing. The results revealed the presence of Flaviviruses and Alphaviruses. Of the 22 Flavivirus pools tested, 18 were positive, with PCR analysis specifically identifying dengue and Zika. Although no arbovirus was identified via RT-PCR, Sanger sequencing detected two Zika-positive samples. Notably, no official Zika cases were reported in 2023, suggesting a potential undetected risk of infection in human populations of Caja Fuego and San Gregorio. This study recommends the implementation of a surveillance campaign in collaboration with the Ecuadorian Ministry of Public Health to mitigate the risk. Full article

Haemosporidian parasites (Apicomplexa, Haemosporida) are diverse obligatory heteroxenous protists, which infect all major groups of terrestrial vertebrates and use dipterous blood-sucking insects as vectors. These pathogens are responsible for various diseases, including malaria, which remains an important human and animal illness. In the wild, haemosporidians are particularly diverse in reptiles and birds in tropical countries, where they are flourishing. Avian haemosporidians have been particularly extensively investigated, especially due to their high prevalence and global distribution, including the countries with cold climates. The general scheme of the life cycle of haemosporidians is known, but the details of development remain insufficiently investigated or even unknown in most of the described parasite species, suggesting the existence of knowledge gaps. This attracts attention to some recent observations, which remain fragmentary but suggest the existence of formerly neglected or underestimated modes of the haemosporidians’ survival in vertebrates. Such findings are worth discussion as they indicate the novel directions in wildlife haemosporidian research. This article overviews some recent findings, which call for broadening of the orthodox views on modes of existence of haemosporidian parasites in avian hosts. Among them are the role of blood merogony in the long-lasting persistence of malaria parasites in birds, the role of gametocytes in the long-lasting survival of Haemoproteus species in vertebrates, the possible reasons of undetectable avian Haemoproteus infections due to peculiarities of exo-erythrocytic development, and the plausible factors driving the narrow vertebrate host specificity of Haemoproteus species. Full article

Clinical success in treating complicated urinary tract infections (cUTIs) depends on accurate pathogen detection, given the common occurrence of polymicrobial infections and antimicrobial resistance. This multicenter, randomized, investigator-blinded study compared polymerase chain reaction (PCR)-based diagnostics to conventional culture and sensitivity (C&S) testing in guiding the treatment of cUTIs. PCR identified polymicrobial infections in 43.52% of cases, a significantly higher rate than that observed with C&S (31.95%, p = 0.033). Patients in the C&S arms with undetected polymicrobial infections had a significantly higher clinical failure rate (33.33%, 14/42, p = 0.041) compared to those with concordant polymicrobial infection identification by both methods (22.22%, 12/54). PCR also detected additional pathogens in 54.44% (92/169) of cases in the C&S arm, where clinical failure was significantly higher when C&S missed pathogens (28.26% vs. 14.29%, p = 0.015). Similarly, when C&S failed to detect phenotypic resistance (compared to PCR), clinical failure occurred in 50% (16/42) of cases, compared to 13.22% (21/121, p = 0.001) when resistance detection was concordant (PCR and C&S). To further illustrate the clinical impact, patient-level case analyses are included to demonstrate how PCR-guided therapy improved pathogen detection and enabled more appropriate antimicrobial selection compared to C&S. These findings highlight the limitations of C&S in detecting polymicrobial infections, antimicrobial resistance, and hetero-resistance due to its limited clonal analysis, supporting the integration of PCR for more accurate diagnostics and optimized cUTI management. Full article

This study aimed to assess the prevalence of HDV (hepatitis delta virus), HCV (hepatitis C virus), and HIV (human immunodeficiency virus) coinfections among HBsAg-positive patients and to determine the severity of liver fibrosis and biochemical markers. Furthermore, the study sought to evaluate the noninvasive fibrosis scores (APRI and FIB4) in predicting the severity of liver disease in patients with hepatitis B. A retrospective analysis of 1434 patients with chronic HBV admitted between January 2020 and December 2024 was conducted at Sincan Tertiary Hospital. The positivity rates of the following antibodies were the focus of the study: anti-HDV, anti-HCV, and anti-HIV. In addition to these, the levels of HIV-RNA, HCV-RNA and HBV-DNA, as well as several biochemical markers (ALT, AST, INR, albumin, bilirubin and platelet count) were also evaluated. The APRI and FIB-4 scores were calculated. Of the 1434 patients, 49 (3.4%) tested positive for anti-HDV, 784 were screened for anti-HCV, and 749 were screened for anti-HIV. The positivity rates were 3.4% (27/784) and 3.4% (26/749), respectively. According to ROC analysis, the FIB-4 score had a statistically significant effect on predicting anti-HDV negativity (AUC = 0.59, p = 0.031). However, the APRI score was not a significant predictor for anti-HDV positivity (AUC = 0.53, p > 0.05). APRI and FIB-4 scores did not have a statistically significant discriminatory power in predicting anti-HCV and anti-HIV positivity (p > 0.05). The cut-off value for the FIB-4 score in predicting anti-HDV positivity was 1.72, with a sensitivity of 61.4% and a specificity of 42.9% (p = 0.031). Among the HCV/RNA-positive patients (n = 5), all were male, and two also had positive anti-HBe results with undetectable HBV/DNA levels. One HIV/RNA-positive patient, a foreign national, was confirmed to have HIV/HBV/HDV infection. All HBsAg-positive patients should undergo routine anti-HDV testing. Vaccination programmes are vital in preventing the spread of HDV. Dual screening strategies are essential for identifying infected individuals and developing prevention and treatment programmes. Anti-HDV positivity indicates advanced liver fibrosis, emphasising the importance of screening and monitoring. However, the limited accuracy of the APRI and FIB-4 scores for detecting coinfections highlights the need to integrate noninvasive methods with molecular diagnostics for precise management. Full article

Background: Antiretroviral therapy has transformed HIV infection from a fatal disease to a chronic and manageable condition, but increasing health issues beyond acquired immunodeficiency syndrome, such as metabolic, liver, and cardiovascular diseases, have been observed. Furthermore, the increasing prevalence of HIV strains resistant to older antiretroviral regimens has necessitated a re-evaluation of treatment strategies. Methods: We performed a retrospective, observational study to evaluate the long-term outcomes of an antiretroviral switch from a non-nucleoside reverse transcriptase inhibitor-based to bictegravir-based regimen; this study aimed to assess the impact of this antiretroviral switch on treatment adherence, the safety profile, and virologic outcomes. The secondary objectives were to analyze the changes in lipid, kidney function, liver function, and anthropometric parameters after switching. Results: A total of 25 patients were included in this analysis; virologic suppression was maintained over time, with 100% of patients demonstrating undetectable viral loads at 6, 12, 24, and 36 months. In parallel, a significant increase in CD4+ cell count was observed after switching. No significant differences were observed compared to the previous therapy regarding anthropometric parameters or laboratory parameters. However, a significant reduction in liver steatosis, as assessed by Fibroscan, was observed. Conclusions: bictegravir-based regimens are a valid therapeutic option for people living with HIV, particularly for those with metabolic comorbidities. Full article

Background and Clinical Significance: Lung cancer, a leading cause of global cancer diagnoses, maintains the highest mortality risk despite advances in treatment. Immunotherapy agents, such as anti-programmed death-1/programmed death ligand-1 (PD-1/PD-L1), have revolutionized care for non-small cell lung cancer (NSCLC). However, the success is tempered by the emergence of immune-mediated adverse reactions, including the rare onset of type I diabetes. The incidence of diabetes mellitus increased during the SARS-CoV-2 pandemic. While there are several cases of new-onset diabetes after COVID-19 and COVID-19 vaccination, no case of new-onset type 1 diabetes after COVID-19 was described in an immune checkpoint inhibitor (ICI)-treated patient. Case Presentation: A 57-year-old male with stage IV NSCLC (brain and liver metastases) who had been treated with nivolumab for 4 years appeared positive for SARS-CoV-2 infection at a routine check. After two weeks, he was admitted to our clinic with severe fatigue, hyperglycemia, hyponatremia, and hyperkalemia. HbA1c level was normal and serum peptide C was undetectable. Nivolumab treatment was ceased, and the patient became fully dependent on basal–bolus insulin. After 3 months, the patient showed a complete imagistic remission. Conclusions: The case presented significant challenges due to the unclear etiology of newly onset diabetes and the uncommon age at which type 1 diabetes is developed. The outcome suggests that anti-PD-1 and SARS-CoV-2 infection can act synergistically. Full article

The management of infectious diseases has proven to be a daunting task for clinicians worldwide, and the rapid development of antibiotic resistance among Gram-negative bacteria is making it even more challenging. The first-line therapy is empirical, and it most often comprises β-lactam antibiotics. Among Gram-negative bacteria, Proteus mirabilis, an important community and hospital pathogen associated primarily with urinary tract and wound infection, holds a special place. This review’s aim was to collate and examine recent studies investigating β-lactam resistance phenotypes and mechanisms of Proteus species and the global significance of its β-lactam resistance evolution. Moreover, the genetic background of resistance traits and the role of mobile genetic elements in the dissemination of resistance genes were evaluated. P. mirabilis as the dominant pathogen develops resistance to expanded-spectrum cephalosporins (ESC) by producing extended-spectrum β-lactamases (ESBL) and plasmid-mediated AmpC β-lactamases (p-AmpC). β-lactamase-mediated resistance to carbapenems in Enterobacterales, including Proteus spp., is mostly due to expression of carbapenemases of class A (KPC); class B (metallo-β-lactamases or MBLs of IMP, VIM, or NDM series); or class D or carbapenem-hydrolyzing oxacillinases (CHDL). Previously, a dominant ESBL type in P. mirabilis was TEM-52; yet, lately, it has been replaced by CTX-M variants, particularly CTX-M-14. ESC resistance can also be mediated by p-AmpC, with CMY-16 as the dominant variant. Carbapenem resistance in Proteus spp. is a challenge due to its intrinsic resistance to colistin and tigecyclin. The first carbapenemases reported belonged to class B, most frequently VIM-1 and NDM-5. In Europe, predominantly France and Belgium, a clonal lineage positive for OXA-23 CHDL spreads rapidly undetected, due to its low-level resistance to carbapenems. The amazing capacity of Proteus spp. to accumulate a plethora of various resistance traits is leading to multidrug or extensively drug-resistant phenotypes. Full article

Background/Objectives: Chlamydia trachomatis (Ct) is a common pathogen causing urogenital, anal, oral, and ocular infections. Although extensive vaccine efforts have been underway for decades, there is no licensed vaccine available to prevent human Ct infection. Polymorphic membrane protein D (PmpD) is a highly conserved protein present on the surface of Ct elementary bodies, suggesting an important role Ct biology. Repetitive tetrapeptide motifs GGA(I,L,V) and FxxN are conserved across Pmps and are important for adhesion in the related Chlamydia pneumoniae Pmp21. Methods: Using bioinformatics approaches, we identified amino acids 270 to 294 of PmpD that included two GGA(I,L,V) motifs and an FxxN motif as vaccine targets. Synthetic peptides corresponding to these regions were chemically conjugated separately via the carboxy (C)- or amino (N)-terminus (FxxN 1.1 and FxxN 1.2) to the surface of Qβ virus-like particles (VLPs) and were tested for immunogenicity and protective capacity in mice. Results: Female mice immunized three times with a mixture of Qβ-FxxN 1.1 and Qβ-FxxN 1.2 vaccines without exogenous adjuvant elicited geometric-mean endpoint dilution titers near 10⁴. Further, mice showed decreased infection at early time points when challenged vaginally with luciferase-expressing Chlamydia muridarum over 9 days and a faster time to undetectable infection compared to controls. Immunization with individual vaccines (Qβ-FxxN 1.1 or Qβ-FxxN 1.2) did not show the same degree of reduction. Conclusions: Vaccination against PmpD tetrapeptide motifs is a novel and promising approach for limiting initial Chlamydia infection and warrants further investigation to characterize the mechanism of protection. Full article