Background: Serological methods are key for tularemia diagnosis. This study evaluated the recombinant SucB protein of Francisella tularensis as a potential antigen for tularemia serodiagnosis using an enzyme-linked immunosorbent assay ELISA. Methods: The succinyltransferase dihydrolipoamide protein (SucB, FTT0077) was selected based on previous studies identifying immunodominant antigens of F. tularensis. The SucB gene was amplified from F. tularensis subsp. holarctica LVS (NCTC 10857), cloned into the pET28a expression vector, and expressed in Escherichia coli BL21 (DE3). Recombinant protein expression was confirmed by SDS-PAGE and Western blot. Immunoblotting with sera from tularemia patients and controls demonstrated strong SucB immunoreactivity. Based on this, a SucB-based ELISA was developed and optimized. Results: The recombinant SucB protein demonstrated strong immunoreactivity with sera from tularemia-positive patients, with minimal cross-reactivity in controls. Receiver operating characteristic (ROC) analysis identified an optimal optical density (OD) cut-off of 0.27 for anti-F. tularensis IgG detection. At this cut-off, the assay showed a sensitivity of 96.8% (95% CI: 93.3–100%) and a specificity of 98.8% (95% CI: 96.7–100%). The positive predictive value (PPV) and negative predictive value (NPV) were 98.92% and 96.59%, respectively, indicating robust diagnostic performance. Agreement analysis demonstrated excellent concordance between the SucB-based ELISA and a commercial diagnostic kit, with a Cohen’s kappa coefficient of 0.96, reflecting near-perfect agreement. Conclusions: This study highlights recombinant SucB as a promising biomarker for tularemia diagnosis. SucB-based ELISA could improve detection, especially in endemic or resource-limited areas. Further research with larger groups is needed to confirm these results.

Background Ticks are important vectors of numerous bacterial and viral pathogens affecting both humans and animals. However, information on the occurrence of Ehrlichia and Bartonella infections in ticks remains limited in many regions, including Iran. This study investigated the molecular occurrence of Ehrlichia canis and Bartonella spp. in ticks collected from small ruminants in Kurdistan Province, western Iran. Methods Ticks were collected from sheep and goats in eight counties of Kurdistan Province between June and August 2024. Tick species were identified morphologically, and genomic DNA was extracted from individual specimens. E. canis and Bartonella spp. were detected using SYBR Green-based and TaqMan real-time PCR assays, respectively. Results A total of 519 ticks were collected from 39 small-ruminant herds. Six tick species were identified: Rhipicephalus bursa (60.9%), Rhipicephalus sanguineus (34.1%), Hyalomma asiaticum (2.5%), Dermacentor kochi (1.5%), Hyalomma anatolicum (0.6%), and Dermacentor marginatus (0.4%). Molecular analysis detected E. canis DNA in 1.5% of tick pools. Positive samples were identified in Dehgolan (1.7%), Qorveh (3.9%), Baneh (1.7%), and Marivan (2.7%) counties and were associated with R. bursa (1.9%) and R. sanguineus (0.6%). No Bartonella DNA was detected in any of the examined tick pools. Conclusion The findings demonstrate low-level circulation of E. canis in livestock-associated ticks in western Iran and suggest heterogeneous spatial distribution of the pathogen. The absence of detectable Bartonella spp. indicates either limited circulation or bacterial loads below the detection limit. Continued molecular surveillance using broader pathogen screening is warranted to improve understanding of the epidemiology of tick-borne bacterial pathogens and support effective surveillance and control programs.

Coxiella burnetii is a zoonotic bacterial pathogen that causes Q fever in humans and coxiellosis in livestock. It represents a significant public health concern and leads to considerable economic losses in the livestock industry. This study aims to determine the rate of environmental shedding of Coxiella burnetii in small ruminant herds in Kermanshah Province, western Iran. A total of 302 sheep and goats from six districts in Kermanshah Province were included in this study. Vaginal and rectal swab samples were collected and tested for Coxiella burnetii by targeting IS1111 gene using TaqMan real-time PCR. Out of 302 small ruminants sampled from 55 herds, the overall molecular prevalence of Coxiella burnetii shedding was 1.65

Background: Tick-borne pathogens (TBPs) pose a significant threat to livestock production in Kerman Province, Iran. Despite the high prevalence of TBPs, our understanding of specific pathogens circulating within local tick populations remains limited. Furthermore, the potential for co-infections with multiple microorganisms complicates the diagnosis and disease management. This study aimed to investigate the prevalence of TBPs in ticks collected from domestic animals in Kerman province using real-time quantitative PCR (qPCR). Methods: Tick collection was conducted between April and June 2022 from 199 domestic animals (63 cattle, 63 sheep, 63 goats, and 10 dogs) across 65 villages in three counties of Kerman Province, Iran. Collected ticks were subjected to qPCR assays targeting Coxiella burnetii, Bartonella spp., Rickettsia spp., Francisella spp., Borrelia spp., and Ehrlichia spp. Phylogenetic analysis of the amplified DNA sequences was performed to elucidate the genetic relationships among the detected pathogens. Results: In this study, 707 ixodid ticks was collected included Hyalomma marginatum marginatum (70.7%, 108 pools) and Rhipicephalus linnaei (29.2%, 27 pools). Based on molecular analysis, Rickettsia spp., Ehrlichia spp, C. burnetii and Bartonella spp. were detected in 55.5%, 9.6%, 8.1% and 0.7%, respectively. Rickettsia aeschlimannii, R. sibirica, R. conorii subsp. israelensis and R. africae were identified based on sequencing and phylogenetical analysis. Co-infections were also observed: 5.9% of the pools (8 pools) were co-infected with Ehrlichia spp. and Rickettsia spp., 3.7% (5 pools) with Rickettsia spp. and C. burnetii, and 0.7% (1 pool) with Rickettsia spp. and Bartonella spp. No infections with Francisella spp. or Borrelia spp. were detected. Conclusions: This study demonstrates the presence of multiple tick-borne pathogens of veterinary and public health significance in ruminants from Kerman Province, highlighting the need for further research on tick-borne diseases affecting both animal and human populations in this and surrounding regions.

Background:Infective endocarditis (IE) is a life-threatening condition caused by diverse microbial agents and remains a major diagnostic and therapeutic challenge, particularly in cases of blood culture-negative IE (BCN-IE). Methods:In this cross-sectional study, 405 formalin-fixed paraffin-embedded heart valve tissue samples from 232 patients with pathologically and clinically confirmed IE who underwent valve replacement were collected between March 2021 and March 2025 from two tertiary referral hospitals in Tehran, Iran. Following DNA extraction, Coxiella burnetii, Brucella spp., and Bartonella spp. were detected using TaqMan real-time PCR, while Tropheryma whipplei was identified by SYBR Green real-time PCR. Species-level identification of Brucella and Bartonella in positive samples was performed using conventional and multiplex real-time PCR. Results:Overall, C. burnetii, Brucella spp., Bartonella spp., and T. whipplei were detected in 6.9%, 8.6%, 5.6%, and 3.0% of patients, respectively. The study population comprised 156 males (67.2%) and 76 females (32.8%), with a mean age of 47 years. The aortic (40.3%) and mitral (39.1%) valves were the most frequently involved sites. Bartonella quintana, Brucella melitensis, and Brucella abortus were identified among positive samples. Dyspnea was significantly associated with C. burnetii (P = 0.02), Bartonella (P = 0.04), and Brucella infections (P = 0.009), while fever (P = 0.03) and sweating (P = 0.001) were significantly associated with Brucella infection. Conclusions:Fastidious and intracellular pathogens are important but overlooked causes of BCN-IE in Iran. Molecular analysis of heart valve tissues represents a valuable diagnostic strategy and supports the need for improved surveillance, prevention, and targeted management of zoonotic and fastidious agents in IE.

Background: The rapid rise in antimicrobial resistance (AMR) represents one of the most pressing global health challenges of the 21st century, threatening antibiotic effectiveness, compromising clinical outcomes, and undermining healthcare systems. Understanding how resistant pathogens emerge and spread across human, animal, and environmental sectors is essential for effective global response. Main body: This review evaluates traditional and advanced AMR detection methodologies, including phenotypic assays, molecular diagnostics, whole-genome sequencing (WGS), metagenomics, and biosensor-based technologies. It also highlights the role of bioinformatics tools, surveillance databases, and integrated platforms that support real-time analysis. Genomic surveillance provides unparalleled resolution for characterizing resistance mechanisms, transmission patterns, and evolutionary trajectories of multidrug-resistant organisms. Techniques such as WGS and metagenomics allow timely and precise identification of resistance genes, improving outbreak detection and strengthening antimicrobial stewardship. Despite these advantages, the adoption of genomic surveillance faces barriers in low- and middle-income countries, including high costs, limited infrastructure, insufficient technical expertise, and the lack of standardized data frameworks. Conclusions: Genomic surveillance is a transformative tool for combating AMR and strengthening global health systems. Effective implementation requires sustained investment, capacity-building, coordinated cross-sector collaboration, and commitment to the One Health approach to ensure equitable access and long-term global impact.

Anthropogenic changes associated with urbanization can bring wildlife species into closer contact with livestock and humans, thereby increasing the risk of pathogen spillover. Recently, urban-adapted (synanthropic) hedgehog species, including Hemiechinus auritus (long-eared) and Paraechinus hypomelas (Brandt’s), have been suggested as potential sources of zoonotic pathogens. The increasing number of tick-infested hedgehogs in urban areas and confirmed cases of human rickettsial infections in south-eastern Iran motivated this investigation to identify rickettsial species in ticks collected from hedgehogs to help assess their potential role in spreading tick-borne diseases. So, this study aimed to screen tick pools collected from synanthropic hedgehogs in southeastern Iran for Rickettsia spp. DNA and to perform presumptive species identification using partial gltA sequencing. Among 60 hedgehogs live-trapped and sampled in two cities (Zabol, Kerman), forty of the long-eared and five of Brandt’s were tick-infested. We collected 68 ticks from 18 hedgehogs trapped in Zabol and 70 ticks from 27 hedgehogs trapped in Kerman. All collected ticks were adults and were morphologically identified as Rhipicephalus sanguineus s.l. or Rhipicephalus turanicus. Ticks collected from each individual hedgehog were pooled together and each pool consisted of ticks belonging to a single species collected from one individual hedgehog. Tick-pool DNA extracts were screened for Rickettsia spp. using a genus-level SYBR Green real-time PCR targeting the gltA gene. Screening-positive pools were confirmed by a TaqMan real-time PCR targeting the 16 S rRNA gene, and samples with Ct values < 31 were subjected to conventional PCR for amplification of an 834-bp gltA fragment. Species-level identification was performed based on partial gltA sequencing, BLAST analysis, and phylogenetic comparison. A total of 5 of 45 tick pools (11.1

Background Bartonella henselae and Bartonella quintana are among the most clinically relevant Bartonella species infecting humans. While B. henselae is a zoonotic pathogen maintained in animal reservoirs, B. quintana is considered a human-restricted bacterium transmitted via the human body louse. Both species can cause a wide range of manifestations, particularly in immunocompromised individuals such as those with HIV/AIDS. This study aimed to estimate the prevalence of IgG and IgM seropositivity to these two species and to identify determinants of seropositivity. Methods This cross-sectional study included 200 participants, comprising 97 HIV-positive patients, 53 patients with AIDS, and 50 healthy individuals as the control group.IgG antibodies against B. henselae and B. quintana were measured in all participants using an indirect immunofluorescence assay (IFA). In addition, IgM antibodies were assessed in a randomly selected subset of 48 participants. Results The overall seroprevalence of B. henselae and B. quintana IgG was 24.0% and 22.0%, respectively, while IgM seropositivity was 18.8% and 22.9%. No significant differences were observed in B. quintana IgG prevalence among control, HIV, and AIDS groups. Individuals with a history of drug abuse had a more than threefold increased likelihood of IgG positivity. For B. henselae, IgG prevalence was higher in the control and AIDS groups compared to HIV-positive individuals, though not statistically significant. Conclusion The significant prevalence of IgG antibodies against both Bartonella species and the presence of IgM antibodies in the selected study group, especially in HIV patients, demonstrate the clinical importance of these pathogens in at-risk populations. These findings emphasize the need for clinical vigilance in symptomatic immunocompromised patients.

Background: Rickettsial diseases are zoonotic infections transmitted by arthropods and remain underrecognized in the World Health Organization Eastern Mediterranean (WHO-EMRO) Region. We conducted a systematic review and meta-analysis to estimate the prevalence of Rickettsia spp. in humans, animals, and ectoparasites across the WHO-EMRO using a One Health perspective. Methods: This systematic literature search was conducted using a predefined and appropriate search strategy across the PubMed, Scopus, and Web of Science databases for studies published between January 2000 and September 2025. Only cross-sectional studies reporting quantitative prevalence data from WHO-EMRO countries were included in this review. A random-effects meta-analysis was performed to estimate the pooled prevalence values. Statistical heterogeneity and potential publication bias were evaluated using established methods. Results: A total of 124 studies from 17 WHO-EMRO countries were included. Among symptomatic patients (n = 3,820), pooled prevalence of Rickettsia was 6.1% (95% CI: 4.2–15.0), with Rickettsia conorii the most frequently identified species. In asymptomatic individuals (n= 677), pooled seroprevalence was 28.2% (95% CI: 0.0–67.7), indicating widespread exposure. Among ectoparasites (37,039 samples), pooled molecular prevalence of Rickettsia was 7.3% (95% CI: 6.8–7.8), higher in fleas (15.1%) than in ticks (6.4%); R. massiliae and R. africae predominated in ticks. In animals, molecular prevalence was 1.8% (95% CI: 1.1–2.5), whereas seroprevalence reached 44.6% (95% CI: 13.6–75.6), particularly in dogs, equids, and camels. Conclusions: Widespread circulation of Rickettsia spp. across the WHO-EMRO region, highlights its persistent yet underrecognized public health burden. Enhanced surveillance, improved molecular diagnostics, and integrated One Health strategies are essential to address regional transmission and guide effective control measures.

Background: Bartonella infections are emerging zoonotic pathogens, primarily transmitted through arthropod vectors or direct contact with animals. Immunocompromised individuals are at increased risk of developing severe complications. Methods: In this cross-sectional study, a total of 370 blood samples were collected from immunocompromised individuals including patients with HIV, AIDS, common variable immunodeficiency (CVID), liver and kidney transplant recipients, and a control group in Imam Khomeini Hospital in Tehran from May 2024 to February 2025. Result: Overall, Bartonella spp. were detected in 7 out of 370 participants (1.89%). All positive cases were among HIV+ (2.8) and AIDS patients (3.9%). Phylogenetic analysis identified all isolates as Bartonella quintana. Univariate analysis suggested that a history of drug abuse and flea infestation seemed to be associated with infection, but due to the rarity of events, multivariate penalized logistic regression did not confirm these as independent risk factors. Cautious interpretation is warranted. Conclusion: This study provides the first molecular evidence of Bartonella quintana infection among immunocompromised patients in Iran, with a notable prevalence observed in HIV-infected individuals, highlighting the need for increased clinical awareness in this population.

Serological methods are currently the most widely used approach for diagnosing tularemia. Identifying and evaluating immunoreactive antigens of Francisella tularensis could significantly enhance the development of an advanced diagnostic method for tularemia. This study aimed to assess three F. tularensis recombinant proteins of F. tularensis for their potential application in serodiagnosis. In the present study, three proteins were selected for evaluation. Outer membrane protein A (FopA, FTT0583), a conserved hypothetical protein (FTT0975), and GroEL protein (FTT1696). Genes from F. tularensis subsp. Holarctica LVS NCTC 10857 were cloned and expressed using the pET28a-E. coli BL21 system. The recombinant proteins were analyzed by SDS-PAGE and confirmed via western blot. After purification, immunoblot assays were performed on sera from tularemia patients and healthy controls to detect anti-F. tularensis IgG antibodies. Successful cloning of all three genes was confirmed by PCR, restriction enzyme digestion, and sequencing. The recombinant proteins were effectively expressed and purified. Immunoblotting with sera from tularemia patients showed seroreactivity rates of 36% for FopA, 24% for FTT0975, and 52% for GroEL. The diagnostic values for combination of these proteins were as follows: FopA-FTT0975 (44%), GroEL-FTT0975 (58%), FopA-GroEL (64%), and FopA-GroEL-FTT0975 (66%). No false positives were found in control sera. Although all three recombinant proteins exhibited moderate diagnostic value individually, they demonstrated enhanced performance when combined. Therefore, these proteins are recommended for use alongside other immunogenic proteins in the development of improved diagnostic tests for tularemia.

Crimean–Congo haemorrhagic fever (CCHF) is an emerging zoonotic disease of significant public health concern caused by Crimean–Congo haemorrhagic fever virus (CCHFV), primarily transmitted by tick vectors. Its spread is further compounded by global warming, tick range expansion, and traditional farming practices. This study aimed to assess the prevalence of CCHFV in ticks parasitizing livestock in Kermanshah Province, Iran, which borders Iraq, a country that has experienced major CCHF outbreaks in recent years. Serum and tick samples were collected from 302 small ruminants (SRs) in six districts, considering previous CCHF cases and regional differences. Following RNA extraction from both ticks and sera, a homemade real-time RT-PCR was used to detect CCHFV infection. All sera tested negative, while 0.67

Tularemia, caused by Francisella tularensis, is a zoonotic disease with various sources, transmission routes, and geographically different clinical signs. Diagnosis is challenging due to nonspecific symptoms, highlighting the importance of laboratory testing for accurate detection, effective outbreak management, and targeted treatment. Recent improvements have enhanced the accuracy of sensitive and specific immunological and molecular methods. Techniques such as enzyme-linked immunosorbent assay, immunochromatography, microagglutination tests, indirect immunofluorescence assays, and PCR continue to be key detection tools. Molecular typing methods such as whole-genome sequencing, single-nucleotide polymorphism analysis, multiple-locus variable-number tandem repeat analysis, pulsed-field gel electrophoresis, and matrix-assisted laser desorption ionization-time of flight enable precise genetic characterization of F. tularensis strains. These methods improve understanding of phylogeny, strain diversity, and transmission routes, while supporting outbreak investigations. This review aims to provide a comprehensive overview of current laboratory methods for diagnosing and typing tularemia as well as their application in clinical and research settings.

Bartonella species are vector-borne zoonotic pathogens responsible for a wide clinical spectrum of human infections, ranging from asymptomatic or subclinical presentations to self-limiting illnesses and severe, potentially life-threatening diseases. However, data on human infections caused by many newly described or lesser-known Bartonella species remain scarce or entirely lacking. We report two cases of lymphadenopathy caused by Bartonella species which are genotypically closely related with Bartonella gabonensis and “Candidatus Bartonella gerbillinarum”, in southern Iran. Bartonella DNA was detected in lymph node biopsy specimens using PCR-based assays. Both patients responded favorably to a combination of antibiotic therapy and surgical management, resulting in complete clinical recovery. These rodent-associated Bartonella species have not previously been documented as human pathogens in clinical settings. Our findings raise significant concerns regarding the potential emergence of rodent-borne bartonellosis and underscore the need for heightened surveillance and further investigation within a One Health framework. Not applicable.

Posterior reversible encephalopathy syndrome (PRES) is an uncommon but serious neurological complication characterized by headache, seizures, visual disturbances, and altered mental status, associated with parieto-occipital vasogenic edema on neuroimaging. Rickettsial infections as a trigger are rarely reported. In this report, we describe a 26-year-old man with rickettsial infection from Iran, who developed diffuse petechial rash, acute kidney injury, recurrent seizures, and bilateral cortical blindness. Brain Magnetic Resonance Imaging (MRI) showed extensive parieto-occipital hyperintensities consistent with PRES. An indirect immunofluorescence assay demonstrated a four-fold rise in IgM antibodies titer, against R. conorii, from 1:24 to 1:96, confirming acute Rickettsia conorii infection. This case highlights R. conorii as a rare infectious cause of PRES and underscores the importance of early recognition and empiric treatment in endemic settings.

Background: Q fever has been neglected as a zoonotic disease in many developing countries. Recent studies indicate that Q fever is an endemic disease in Iran. Nevertheless, epidemiological data have not yet been collected from some parts of Iran. This study aimed to conduct a molecular investigation of Coxiella burnetii infection among small ruminants with a history of abortion in western Iran. Methods: In this study, 315 vaginal discharge samples were collected from goats and sheep with a history of abortion in different counties of the Kurdistan province. Genomic DNA was extracted from the collected samples and tested for detection of IS1111 elements of C. burnetii using qPCR. Results: C. burnetii was detected in 4.1% of the vaginal samples. The prevalence of C. burnetii in goats and sheep was 3.3% and 5.9%, respectively. The highest infection rate was observed in Bijar county (17.8%). Conclusion: In this study, the presence of C. burnetii in vaginal samples from small ruminants was confirmed in western Iran. Shedding of this bacterium by infected livestock poses a risk of spreading the infection to other livestock and the possibility of transmitting the infection to humans; therefore, the health system must be vigilant in this regard.

Background: Vector-borne diseases, especially those carried by ticks, are one of the major public health challenges worldwide, especially in tropical and subtropical regions. Ticks, as vectors and reservoirs of dangerous pathogens, play an important role in the transmission of common diseases between humans and animals. Relapsing fever caused by Borrelia spp. is one of these diseases that has become endemic in many regions of the world, as well as in Iran.Method: Blood samples and ticks were collected from small ruminants in eight counties of Kurdistan province, Western Iran. DNA from collected ticks and blood samples was extracted, and all were tested for the detection of the 16S rRNA gene of Borrelia spp. by quantitative polymerase chain reaction (qPCR). For the identification of Borrelia species, flaB and groEL genes were amplified by polymerase chain reaction (PCR) and then sequenced.Result: In this study, 416 blood samples from sheep and goats and 520 collected ticks from these animals were examined from eight counties in Kurdistan Province. Molecular analyses revealed that 3.1% of the blood samples and 1.74% of the tick samples were infected with Borrelia spp. The highest infection rates in both livestock and ticks were observed in Marivan County. The identified tick species were predominantly Rhipicephalus bursa (60.9%) and Rhipicephalus sanguineus (33.4%), and all positive tick samples belonged to these two species. Phylogenetic analysis of flaB and groEL gene sequences confirmed the presence of Borrelia lonestari and Borrelia theileri in blood samples.Conclusion: This study provides the molecular evidence of Borrelia species in livestock and ticks from Kurdistan Province, Iran. However, the limited number of positive samples and the restriction of sampling to a single province should be considered when interpreting these results. Broader studies covering multiple regions and host species are needed to better understand the epidemiology of Borrelia infections in Iran.

INTRODUCTION:Coxiella burnetii is the etiological agent of Q fever, a zoonotic infection recognized in various regions of Iran. Despite its significance, few studies have focused on determining C. burnetii genotypes in Iran. This study aimed to assess the genetic diversity of C. burnetii in Iran using the Multiple-Locus Variable-Number Tandem Repeat Analysis (MLVA) method. METHODS:A total of 26 C. burnetii-positive specimens were selected from a repository of 119 specimens collected from various locations across Iran. These samples were previously identified as C. burnetii using nested PCR and TaqMan real-time PCR techniques. In this study, the MLVA method was utilized for genotyping C. burnetii isolates. RESULTS:Genotyping results from the 26 C. burnetii-positive samples indicated that nearly all loci were informative for genotyping, except two loci (ms23 and ms26). Cluster analysis of the MLVA profiles identified 13 clusters, along with 40 singleton genotypes. Iranian isolates were distributed across a single cluster (Cluster 13), which consisted exclusively of Iranian strains, and 24 unique singleton genotypes, highlighting the genetic diversity of C. burnetii circulating within the region. DISCUSSION AND CONCLUSION:The genotypic characteristics of C. burnetii observed in Iran differed significantly from those found in other global regions, suggesting unique local adaptations of this microorganism. To enhance our understanding of the epidemiology of Q fever in Iran, further large-scale studies are required to evaluate the distribution of C. burnetii genotypes across various geographic areas, host species, and environmental reservoirs.

BACKGROUND:Prosthetic valve Endocarditis (PVE) is an uncommon but potentially life-threatening infection involves a valve prosthesis or annuloplasty ring. Streptococci, including Streptococcus mitis and enterococci are major etiological agents, with studies indicating their significant role in late-onset PVE in some regions of world, staphylococci have surpassed streptococci as the most frequent causative organism. Despite challenges in diagnosis, molecular methods offer high sensitivity. CASE PRESENTATION:A 30-year-old female patient, Iranian, with a history of hypothyroidism, tetralogy of Fallot, and a bioprosthetic valve replacement and weakness after two months from exprience upper respiratory tract infection (URTI), was admitted with complaints of epistaxis, fever and worsening of shortness of breath. She exhibited symptoms of anemia, thrombocytopenia, elevated WBC, LDH, and D-dimer levels, along with splenomegaly, pleural effusions, and pulmonary congestion. Echocardiography revealed significant valve vegetation and RV failure. Despite comprehensive treatment, including cardiac surgery and antifungal therapy, her condition deteriorated, leading to cardiac arrest and death. Posthumous molecular analysis identified S. mitis as the causative agent, despite negative blood cultures. CONCLUSIONS:This case highlights the challenges of diagnosing and treating complex PVE, particularly when conventional cultures are negative. The detection of S. mitis through molecular methods underscores the importance of early and accurate identification of pathogens in guiding effective treatment.

INTRODUCTION AND PURPOSE:Brucellosis is a prevalent bacterial zoonosis globally, affecting a broad range of hosts. The role of rodents in the survival and transmission of Brucella species to humans remains uncertain. This study aimed to investigate the prevalence of Brucella infection among wild rodents in western Iran, specifically in KabudarAhang County within Hamadan Province. MATERIALS AND METHODS:Sampling was conducted across various regions of KabudarAhang County in western Iran between April 2014 and September 2017. Serological testing was performed using the standard tube agglutination method while molecular investigation was carried out through real-time PCR analysis. Subsequently, molecularly positive samples underwent species identification via conventional PCR. RESULTS:Serological testing revealed 7 positive samples (1.76%), including four Meriones persicus, one Mus musculus, one Meriones libycus, and one Spermophilus fulvus. In the molecular survey, three samples (0.68%) tested positive for Brucella; these included one M. musculus and two M. persicus. The molecular species identification test detected B. abortus in M. musculus among those positive for Brucella. CONCLUSION:These findings suggest that wild rodents may play an overlooked role in the maintenance of pathogenic Brucella species in natural environments. Furthermore, in situations where standard diagnostic guidelines for brucellosis in wildlife are not well established, employing multiple testing approaches is crucial for accurate detection.