Identification Of Causative Agent Research Articles

Time to Positivity in Blood Culture Bottles Inoculated with Sonication Fluid from Fracture-Related Infections

The timely and accurate identification of causative agents is crucial for effectively managing fracture-related infections (FRIs). Among various diagnostic methods, the “time to positivity” (TTP) of cultures has emerged as a valuable predictive factor in infectious diseases. While sonication of implants and inoculation of blood culture bottles with sonication fluid have enhanced sensitivity, data on the TTP of this microbiological technique remain limited. Therefore, patients with ICM criteria for confirmed FRI treated at our institution between March 2019 and March 2023 were retrospectively identified and their microbiological records were analyzed. The primary outcome parameter was TTP for different microorganism species cultured in a liquid culture collected from patients with confirmed FRI. A total of 155 sonication fluid samples from 126 patients (average age 57.0 ± 17.4 years, 68.3% males) was analyzed. Positive bacterial detection was observed in 78.7% (122/155) of the liquid culture pairs infused with sonication fluid. Staphylococcus aureus was the most prevalent organism (42.6%). Streptococcus species exhibited the fastest TTP (median 11.9 h), followed by Staphylococcus aureus (median 12.1 h) and Gram-negative bacteria (median 12.5 h), all of which had a 100% detection rate within 48 h after inoculation. Since all Gram-negative pathogens yielded positive culture results within 24 h, it could be discussed if empirical antibiotic therapy could be de-escalated early and limited towards the Gram-positive germ spectrum if no Gram-negative pathogens are detected up to this time point in the context of antibiotic stewardship.

Review on Current Diagnostic Methods of Bovine Mastitis

Mastitis is an inflammation of the mammalian gland, and it is a commercially significant ailment in the dairy industry worldwide. Based on the source, it can be either contagious or environmental; on the other hand, clinical and subclinical mastitis are based on their severity. The most important step between disease etiology and cure is accurate disease diagnosis. A cost-effective, dependable, and quick diagnostic instrument is essential for udder health management. Therefore, the objective of this article is to review current diagnostic methods for bovine mastitis. The diagnostic methods include clinical diagnosis, microscopically examined specimens, conventional methods, power of hydrogen (pH) tests, microbial culture, molecular methods, and those based on emerging technology. Conventional methods like the strip cup test, California mastitis test, Wisconsin mastitis test, somatic cell count test, and electrical conductivity test are used as screening tests that are not specific to any pathogen. Microbial culture-based methods are the gold standard for identifying mastitis pathogens and are frequently used, but they have some drawbacks. Advanced molecular methods such as polymerase chain reaction and its version, loop-mediated amplification, are used for the identification of causative agents at the strain level. Emerging technologies such as infrared thermography and biosensors have the potential to match or surpass the diagnostic methods mentioned above concerning sensitivity, selectivity, accuracy, and realism. Emerging technologies are growing at a fast pace to diagnose human cases, but applications for the veterinary market, and specifically, for the diagnosis of mastitis, remain limited. Both specializations in training and experience in the interpretation of results are needed for implementing advanced technologies for efficient mastitis diagnosis and improving udder health management. It should be better to adopt and employ advanced diagnostic methods, such as advanced molecular tests and emerging technology.

Ochratoxin A contamination of California pistachios and identification of causal agents.

Ochratoxin A (OTA) is a potent mycotoxin produced by Aspergillus and Penicillium spp., which contaminates many crops, including pistachios. Pistachios contaminated with OTA may be subjected to border rejections resulting in significant economic losses to the United States agricultural revenues. The current study examined prevalence of OTA in California grown pistachios and identified its causal agents. OTA was detected in 20% samples from 2018-21 (n=809), with 18% samples exceeding the European Union regulatory limit of 5 µg/kg. Fungi potentially responsible for OTA contamination were isolated from leaves, nuts, and soil collected from 14 pistachio orchards across California. A total of 1,882 isolates of Aspergillus section Nigri and 85 isolates of section Circumdati were recovered. Within section Nigri, 216 (11.5%) isolates were identified as potential OTA producers using a boscalid-resistance assay. Phylogenetic analyses of partial gene sequences for β-tubulin and calmodulin genes resolved section Circumdati into four species: A. ochraceus (33%), A. melleus (28%), A. bridgeri (21%), and A. westerdijkiae (19%). Aspergillus westerdijkiae produced the highest levels of OTA in inoculated pistachios (47 µg/g), followed by A. ochraceus (9.6 µg/g) and A. melleus (3.3 µg/g). Aspergillus bridgeri did not produce OTA. OTA production by section Circumdati was optimal from 20 to 30ºC. All 216 boscalid-resistant isolates from section Nigri were identified as A. tubingensis and representative isolates (n =130) produced 3.8 µg/kg OTA in inoculated pistachios. This is the first detailed report on OTA contamination and causal fungi in California pistachios and will be helpful in devising effective management strategies.

Evaluation of a computational model for mycetoma-causative agents identification.

The therapeutic strategy for mycetoma relies heavily on the identification of the causative agents, which are either fungal or bacterial. While histopathological examination of surgical biopsies is currently the most used diagnostic tool, it requires well-trained pathologists, who are lacking in most rural areas where mycetoma is endemic. In this work we propose and evaluate a machine learning approach that semi-automatically analyses histopathological microscopic images of grains and provides a classification of the disease as eumycetoma or actinomycetoma. The computational model is based on radiomics and partial least squares. It is assessed on a dataset that includes 890 individual grains collected from 168 patients originating from the Mycetoma Research Centre in Sudan. The dataset contained 94 eumycetoma cases and 74 actinomycetoma cases, with a distribution of the species among the two causative agents that is representative of the Sudanese distribution. The proposed model achieved identification of causative agents with an accuracy of 91.89%, which is comparable to the accuracy of experts from the domain. The method was found to be robust to a small error in the segmentation of the grain and to changes in the acquisition protocol. Among the radiomics features, the homogeneity of mycetoma grain textures was found to be the most discriminative feature for causative agent identification. The results presented in this study support that this computational approach could greatly benefit rural areas with limited access to specialized clinical centres and also provide a second opinion for expert pathologists to implement the appropriate therapeutic strategy.

Formation of the mutagenic DNA lesion 1,N2-ethenoguanine induced by heated cooking oil and identification of causative agents

BackgroundThe DNA-damaging compounds in heated cooking oil were identified as guanosine adducts. Heated vegetable oil was subjected to deep-frying conditions at 170 °C for 45 min, reacted with isopropylidene guanosine (ipG) at pH 7.4, and the resulting compounds were separated by high-performance liquid chromatography (HPLC).ResultsTwo adducts, 8-hydroxy-ipG and 1,N2-etheno-ipG, were identified in the reaction mixture. One of the major components in heated cooking oil, 2,4-heptadienal (HDE), efficiently produced etheno-ipG from ipG in the presence of tBuOOH. An oxidized HDE solution was fractionated using HPLC to identify causative agents, and each fraction was tested for etheno-ipG formation. In addition to the known lipid peroxidation product, 4,5-epoxy-2-heptenal, two unknown polar components with potent etheno-ipG formation activity were discovered. Based on Mass and UV spectra, their structures were identified as 6-oxo- and 6-hydroxy-2,4-HDE. Similarly, 6-oxo- and 6-hydroxy-2,4- decadienal (DDE) were formed from 2,4-DDE. Significant amounts of 6-oxo- and 6-hydroxy-2,4-alkadienal were detected in the heated cooking oil. These compounds induced the formation of 1,N2-ethenoguanine in nucleosides and DNA, especially in the presence of tBuOOH. Moreover, the formation of 6-oxo- and 6-OH-HDE from 2,4-HDE was accelerated in the presence of hemin and tBuOOH.ConclusionThe results suggest that these compounds are not only generated during the oil heating process but also produced from 2,4-alkadienal through digestion under normal physiological conditions, especially after ingesting heme- and alkyl-OOH-containing diets. Moreover, these compounds can be formed within cells under oxidative stress, potentially linking them to gastrointestinal carcinogenesis.

Promising potential of machine learning-assisted MALDI-TOF MS as an effective detector for Streptococcus suis serotype 2 and virulence thereof.

To the best of our knowledge, this study reveals a strong correlation between mass spectra pattern and virulence phenotype among S. suis for the first time. In order to make the findings applicable and to excavate the intrinsic information in the spectra, the classifiers based on the machine learning algorithms were established, and RF (Random Forest)-based models have achieved an accuracy of over 90%. Overall, this study will pave the way for virulent SS2 (Streptococcus suis serotype 2) rapid detection, and the important findings on the association between genotype and mass spectrum may provide a new idea for the genotype-dependent detection of specific pathogens.

Comprehensive Investigation of Die-Back Disease Caused by Fusarium in Durian.

Durian (Durio zibethinus L.) is an economically important crop in the southern and eastern parts of Thailand. The occurrence of die-back disease caused by plant pathogenic fungi poses a serious threat to the quality and quantity of durian products. However, the identification of causal agents has been a subject of mixed information and uncertainty. In this research, we conducted a comprehensive investigation of die-back disease in nine durian plantations located in Thailand. By analyzing a total of 86 Fusarium isolates obtained from infected tissues, we aimed to provide clarity and a better understanding of the fungal pathogens responsible for this economically significant disease. Through a combination of colony characteristics, microscopic morphology, and a multilocus sequence analysis (MLSA) of the internal transcribed spacer (ITS) region, translation elongation factor 1-α (TEF1-α) gene, and RNA polymerase II gene (RPB2) sequences, we were able to identify and categorize the isolates into three distinct groups, namely, Fusarium incarnatum, F. solani, and F. mangiferae. Koch's postulates demonstrated that only F. incarnatum and F. solani were capable of causing die-back symptoms. This research represents the first report of F. incarnatum as a causal agent of die-back disease in durian in Thailand. Additionally, this study uncovers the association of ambrosia beetles and F. solani, highlighting the potential involvement of E. similia in facilitating the spread of die-back disease caused by Fusarium in durian.

Evaluation of a commercial NGS service for detection of bacterial and fungal pathogens in infectious ulcerative keratitis.

To compare results from a commercial next-generation sequencing (NGS) service to corneal cytology and culture for identification of causative organisms in veterinary patients presenting for infectious ulcerative keratitis (IUK). Swabs for corneal aerobic and fungal cultures and DNA swabs for NGS were submitted for canine and equine normal controls (n=11 and n=4, respectively) and IUK patients (n=22 and n=8, respectively) for which microbrush cytology specimens confirmed the presence of infectious organisms. The sensitivity of the NGS results was compared with bacterial and fungal culture results. Concordance between the NGS and culture results was determined. The NGS results were positive for bacterial and fungal organisms in 5 and 1 normal and 18 and 1 IUK cases, respectively. Bacterial and fungal cultures were positive for 7 and 2 normal and 20 and 5 IUK cases, respectively. Sensitivity of NGS was 82.14% (95% confidence interval (CI), 63.11% to 93.94%) and specificity was 76.47% (95% CI, 50.10% to 93.19%). Concordance (complete and partial) between identified bacterial and fungal organisms was found in 79% and 100% of cases, respectively. NGS identified organisms in 3 culture-negative IUK samples. A commercial NGS service may be useful in the identification of causative agents in IUK cases with a sensitivity greater than the sensitivity previously reported for aerobic culture. Further testing is needed to determine the clinical significance of additional organisms isolated by NGS from infected cases, as well as organisms isolated from normal corneas.

Aflatoxin contamination of maize and groundnut in Burundi: Distribution of contamination, identification of causal agents and potential biocontrol genotypes of Aspergillus flavus.

Aflatoxin contamination of the staples maize and groundnut is a concern for health and economic impacts across sub-Saharan Africa. The current study (i) determined aflatoxin levels in maize and groundnut collected at harvest in Burundi, (ii) characterized populations of Aspergillus section Flavi associated with the two crops, and (iii) assessed aflatoxin-producing potentials among the recovered fungi. A total of 120 groundnut and 380 maize samples were collected at harvest from eight and 16 provinces, respectively. Most of the groundnut (93%) and maize (87%) contained aflatoxin below the European Union threshold, 4 μg/kg. Morphological characterization of the recovered Aspergillus section Flavi fungi revealed that the L-morphotype of A. flavus was the predominant species. Aflatoxin production potentials of the L-morphotype isolates were evaluated in maize fermentations. Some isolates produced over 137,000 μg/kg aflatoxin B1. Thus, despite the relatively low aflatoxin levels at harvest, the association of both crops with highly toxigenic fungi poses significant risk of post-harvest aflatoxin contamination and suggests measures to mitigate aflatoxin contamination in Burundi should be developed. Over 55% of the L-morphotype A. flavus did not produce aflatoxins. These atoxigenic L-morphotype fungi were characterized using molecular markers. Several atoxigenic genotypes were detected across the country and could be used as biocontrol agents. The results from the current study hold promise for developing aflatoxin management strategies centered on biocontrol for use in Burundi to reduce aflatoxin contamination throughout the value chain.

Bacterial Diseases of Bioenergy Woody Plants in Ukraine

In this study, the characterization of several bacterial diseases affecting silver birch (Betula pendula Roth.), common ash (Fraxinus excelsior L.), white poplar (Populus alba L.), and white willow (Salix alba L.) in Ukraine were described. The typical symptoms, features of pathogenesis, and characteristics of the causative agents of the most common bacterial diseases of these tree species were shown. The following types of bacterioses were noted to be especially dangerous, namely, bacterial wetwood, fire blight, bacterial canker, and tuberculosis. Bacterial necrosis of the bark was a less dangerous disease. At the same time, all of the listed types of bacterioses were registered within the forest areas of the investigated region. The study revealed that bacterial wetwood of birch and poplar was caused by Lelliottia nimipressuralis; the bacterial canker of poplar is Pseudomonas syringae (Pseudomonas syringae f. populi and Pseudomonas cerasi); the fire poplar blight is caused by Pseudomonas cerasi (P. syringae); the common ash tuberculosis is caused by Pseudomonas syringae pv. savastanoi; and the bacterial wilt of the willow is caused by Brenneria salicis. The phenomenon of the introduction of microorganisms of different functional orientations as well as the formation of conditions for their activity in the rhizosphere of plants have been studied. In the future, it will provide the development of effective methods for the rapid identification of causative agents of bacterioses and plant protection measures based on multi-functional microbiological preparations based on highly effective strains of microorganisms.

Molecular evidence of hookworms in public environment of Bangladesh

Accurate diagnosis by precise identification of causative agents is essential for the effectiveness of any control interventions. Despite high zoonotic potential, available literature on hookworms in Bangladesh is still scarce and nonspecific. The objective of this study was to determine the occurrence of hookworms in public locations across northeastern Bangladesh (Sylhet metropolitan area) using integrated parasitological and molecular assays. A total of 130 samples (80 soil and 50 environmental canine feces) were collected and examined using modified flotation technique and formalin-ether sedimentation methods. Modified plate culture was used to isolate larvae. The identification was made based on morphometric features and confirmed by amplifying the ITS region of the nuclear rDNA. Overall, 66.2% (86/130) of examined samples were positive for hookworms infection. Characteristic eggs (61–68 × 29–37 μm) and/or larvae of hookworms were observed in 73.8% (59/80) soils and 54.0% (27/50) environmental fecal samples. Rhabditiform larvae (0.48–0.54 × 0.04–0.07 mm) were observed in cultured samples. Genetic analysis of rDNA sequences revealed the presence of Ancylostoma caninum and Ancylostoma ceylanicum. In this study, hookworms' contamination of the public environment was substantial. To the best of our knowledge, this is the first molecular proof of A. caninum and A. ceylanicum observed in urban public environment in Bangladesh.

Clinical case of isolation and identification of <I>Streptococcus equi subsp. Zooepidemicus</I>

Streptococci manifest their pathogenic properties by reducing the overall resistance of the organism or individual tissues.Purpose of the work: isolation, identification and study of the biological properties of isolates isolated from the foal.A pure culture was obtained, morphological, cultural and biochemical properties were studied.For the subsequent identification of streptococci to species, two api 20 Strep test systems (BIOMERIEUX, France) were used. To determine the serological group of streptococci, a latex agglutination test was used using a kit for diagnosing streptococci of groups A, B, C, D, F, and G (OXOID, UK).Laboratory methods of diagnostics for the identification of causative agents of streptococcosis and their species differentiation have been studied. Virulent Streptococcus equi subsp. zooepidemicus caused abscesses in the area of the elbow joint of the foal. Isolation of bacterial cultures was carried out by the bacteriological method. Isolated Streptococcus equi subsp. zooepidemicus had the fermentation of a number of carbohydrates: sorbitol, there was no splitting of lactose, tregolose. Streptococcus equi subsp. zooepidemicus hydrolyzed esculin, no D-ribose fermentation was noted. However, the fermentation of carbohydrates is not a stable and clear sign, therefore it is not used for differentiation and identification of streptococci.When inoculated on blood agar with 5% sheep blood after cultivation for 24 hours at 37 0C, small gray-white colonies were found, surrounded by a wide transparent zone of beta-hemolysis. Catalase test is negative.As a result, it was found that the isolated culture belongs to the species Streptococcus equi subsp. zooepidemicus belonging to group C according to Lancefield.Modern laboratory diagnostics requires an integrated approach to identification, which includes bacteriological and serological methods - polyphase analysis. When identifying streptococci, the determination of their serological group according to Lancefield is of great importance. For this purpose, a latex agglutination reaction is convenient using a kit for diagnosing streptococci of groups A, B, C, D, F and G (OXOID, UK), coagglutination "Streptotest A, B, C, D, G" (AQUAPAST).

Identification of fungal diseases of Swertia chirayita of Sankhuwasabha district

Swertia chirayita is one of the important medicinal and highly traded plant for commercial purpose. However, its production has significantly declined in recent days due to incidence of various diseases. Unfortunately, the knowledge on disease and its causative agent is insufficient. Therefore, the present study focuses on incidence and severity of disease and identification of causative agents. The disease incidence of plant of study cultivated field of Sankhuwasabha district was 53.20% and the disease severity was 23.87%. Leaf spot disease caused by Alternaria alternata, Botrytis cinera and Bipolaris sorokiniana, leaf blight caused by Colletotrichum gloeosporioides and Fusarium wilt by Fusarium oxysporum and rot disease caused by Trichoderma harzianium were identified in Swertia chirayita.

T2Bacteria and T2Resistance Assays in Critically Ill Patients with Sepsis or Septic Shock: A Descriptive Experience.

The use of rapid molecular tests may anticipate the identification of causative agents and resistance determinants in the blood of critically ill patients with sepsis. From April to December 2021, all intensive care unit patients with sepsis or septic shock who were tested with the T2Bacteria and T2Resistance assays were included in a retrospective, single center study. The primary descriptive endpoints were results of rapid molecular tests and concomitant blood cultures. Overall, 38 combinations of T2Bacteria and T2Resistance tests were performed. One or more causative agent(s) were identified by the T2Bacteria assay in 26% of episodes (10/38), whereas negative and invalid results were obtained in 66% (25/38) and 8% (3/38) of episodes, respectively. The same pathogen detected by the T2Bacteria test grew from blood cultures in 30% of cases (3/10). One or more determinant(s) of resistance were identified by the T2Resistance assay in 11% of episodes (4/38). Changes in therapy based on T2Bacteria and/or T2Resistance results occurred in 21% of episodes (8/38). In conclusion, T2Bacteria/T2Resistance results can influence early treatment decisions in critically ill patients with sepsis or septic shock in real-life practice. Large, controlled studies remain necessary to confirm a favorable impact on patients' outcomes and antimicrobial stewardship interventions.

Molecular survey of certain protozoan agents that cause diarrhea in children in Sudan

Introduction Diarrhea is a significant health problem in third world countries; identification of causative agents of diarrhea is essential to apply measures to prevent and control this disease. In addition, scant data are available regarding childhood diarrhea in Sudan. Our research aimed to determine the incidence of specific protozoan pathogens (Entameobia histolytica, Cryptosporidium spp., and Gardia lambelia) among the young (aged less than five years) in Khartoum, Sudan. Methods We conducted a parasitological cross-sectional survey, and stool samples from 437 patients were examined for E. histolytica, C.  parvum, and G. lambelia using a multiplex real-time PCR method. Results Of the 437 stool samples tested, infection with intestinal parasite was found in 155 (35.5%) cases, and co-infection was identified in 16 (3.7%) cases. G. lambelia (18.8%) and C. parvum (15.8 %) were the most frequently identified parasites, followed by E. histolytica (0.5%). The highest and lowest rates of parasitic infections were seen in the less than two years age group (32.7%), and in the 2–4-year-old group (2.7%), the male children showed higher rates of infections (23.7%) compared to females (11.7%). The incidence of protozoan infection was higher (37.7%) in the rainy season (August to December) (32.7%) in contrast with that (2.7%) in the dry season (April to June). Discussion Our present study demonstrated the high prevalence of G. lambelia and C. parvum in children with diarrhea in Khartoum State and the multiplex real-time technique's usefulness in disclosing pathogenic protozoal agents. Our result highlighted the necessity of developing intervention measurement and control strategies to deal with childhood parasitic diarrhea in this region.

S6.5d Molecular identification of mycetoma causative agents from patients in ahospital setting in Senegal

S6.5 Efforts of improving the management of mycetoma: working towards the 2030 goals, September 22, 2022, 4:45 PM - 6:15 PM BackgroundMycetoma is a chronic granulomatous inflammatory disease that is caused either by bacteria or fungi. The diagnosis of species is important to guide the therapeutic management of patients particularly for white and yellow grains. However, the identification of the causative agents using mycological and histological techniques is a real problem in our countries. This study aims to identify etiologic agents using molecular techniques in Senegal.MethodsA prospective study was carried out to compare mycological and histological techniques with molecular methods in patients attending hospital settings. Biopsy specimens and/or grains obtained from these patients were examined by PCR targeting the ITS (fungal agents) and 16S (actinomycosis agents) genes. Sequencing with the SANGER method allowed us to identify the species.ResultsPreliminary results were obtained from 30 patients. The grains collected were black (38%), red (4.7%), white (47.6%), and yellow (9.5%). Discriminative PCR ITS vs 16S identified 5 actinomycosis agents including white and yellow grains and 1 fungal agent. The fungal agent was identified after sequencing as Microsporum langeronii.ConclusionThe preliminary results of this study show the importance of discriminative PCR to guide the therapeutic choice of clinicians. Its widespread use could improve the detection and management of mycetoma cases in Senegal.

P411 Genus specific real-time PCR-a promising technique for rapid diagnosis of fungal keratitis

 Poster session 3, September 23, 2022, 12:30 PM - 1:30 PMObjectiveComparison of different existing molecular methods for diagnosis of fungal keratitis (FK) and to develop and validate genus-specific PCR for identification of most predominant FK causative agents.MethodA prospective multicentric study was performed between November 2019 to August 2021 from four centers across India. Corneal tissue/scraping samples were collected from patients with suspected keratitis for preliminary microbiological workup at respective centers and molecular diagnosis at the Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh. A total of 87 corneal button samples were used for standardization. All samples were subjected to DNA extraction followed by molecular diagnosis using pan-fungal primers by conventional PCR, semi-nested PCR, and real-time PCR targeting the internal transcribed spacer (ITS) region of rDNA. The genus-specific primers for the most common causative agents of FK (Aspergillus sp., Fusarium sp., Alternaria sp., and Curvularia sp.) were designed in ITS2 region and standardized for real-time PCR. The best performing protocol was validated in 145 corneal samples.ResultA total of 68 patients out of 87 were diagnosed with FK of which 91.17% (n = 62/68) were microscopy positive and 82.3% (n = 56/68) were culture positive. Among the culture positive, the most common isolate was Aspergillus sp. (26, 46.42%) followed by Fusarium sp. (21, 37.5%) while the remaining samples grew dematiaceous fungi. Real-time PCR targeting ITS2 region proved to be most sensitive (52.94%) and specific (84.21%) compared with conventional PCR and semi-nested PCR. Genus-specific real-time PCR for Aspergillus sp. and Fusarium sp. showed improved sensitivity and specificity of 82.76%, 87.18%, and 90.91%, 93.48% respectively compared with all other diagnostic methods used in the study. The positive (PPV) and negative predictive value (NPV) for Aspergillus sp. specific PCR were 82.76% and 87.18% while Fusarium sp. specific PCR showed PPV of 86.96% and NPV of 95.56%. Genus-specific real-time PCRs did not show any amplification of 19 FK negative samples while faint amplification was observed in conventional PCR which on sequencing proved to be non-specific. No cross-reactivity was observed in clinical sample standardization. Due to the lack of Alternaria sp. and Curvularia sp. positive clinical samples, both PCRs were standardized using respective culture DNA which showed a positive result. Aspergillus sp. and Fusarium sp. genus-specific PCRs were further validated in 145 corneal samples, of which 91 were FK positive and showed similar results as that of standardization data. Genus-specific PCRs also reduced the turnaround time (˂24 h) by decreasing the need for the identification of causative agents.ConclusionReal-time PCR targeting ITS 2-region, particularly the genus-specific PCRs proved to be the most efficient for molecular diagnosis of FK. The genus-specific PCRs reduce the turnaround time by avoiding the need for sequencing and thus facilitating in rapid diagnosis of FK.

P148 Emerging and cryptic Aspergillus species isolated from hospitalized patients with underlying primary immunodeficiencies

Poster session 2 September 22 2022 12:30 PM - 1:30 PM ObjectivesAlthough Aspergillus fumigatus is the most common etiologic agent of invasive aspergillosis multiple poorly recognized non-fumigatus species have been reported from patients with iatrogenic immunosuppression and individuals with underlying primary immunodeficiencies (PIDs). The species-level identification of causative agents and the determination of antifungal susceptibility patterns can play significant roles in the outcome of aspergillosis. In the current study we aimed to investigate the frequency of non-fumigatus Aspergillus species isolated from hospitalized patients with PIDs at National Institutes of Health (NIH) Clinical Center Bethesda MD USA.MethodsIn a prospective study between January 2019 and December 2021 a total of 279 Aspergillus species were isolated from NIH hospitalized patients with underlying PIDs. The species-level identification of each isolate was attempted by colony morphology microscopic characteristics matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) and PCR-sequencing of the internal transcribed spacer (ITS) region of ribosomal DNA the β-tubulin and Calmodulin (CaM) genes.ResultsOverall members of Aspergillus section Fumigati were the most common group (71%) followed by section Veriscolores (7%) section Usti (4%) section Tanneri (4%) section Terrei (3%) section Nigri (3%) and section Nidulantes (3%). Aspergillus species belong to sections Falvi Clavati Flavipedes and Circumdati were less frequent and each counted for only 1% of the total isolates identified.Notably cryptic and non-fumigatus members of section Fumigati comprised only 12% of the isolates including A. felis A. udagawae A. lentulus A. thermomutatus A. viridinutans, and A. pseudoviridinutans while A. fumigatus was the dominant species (88%).MALDI-TOF assay was able to properly differentiate sections of Aspergillus from each other. However PCR-sequencing of the β-tubulin gene was the most reliable target to separate the cryptic species of each section.ConclusionOur study shows that frequency of rare and cryptic Aspergillus species that primarily affect patients with PIDs may significantly differ from those with acquired immunodeficiencies.Due to their lower susceptibility to available antifungal agents than A. fumigatus correct and prompt identification at the species level is critical for appropriate therapy to improve patient outcomes.In addition DNA sequence-based species identification targeting β-tubulin gene is more accurate than ITS and CaM genes and using MALDI-TOF to differentiate the emerging and cryptic Aspergillus species.

Identification of Causative agents associated with decay of Trees Twig and Orchards Die-back and their Impacts on Vessels of Citrus, Date Palm and Ficus

The present work is concerned with the studies of the organism causing wood decay of twigs and branches of citrus orchards, date palm Phoenix dactylifera L, and ficus trees. A survey for the occurrence of this disease in the main growing areas was achieved by the researchers. The following species of citrus orchards [lime (C. aurantifolia), sweet orange (C. sinensis), and mandarin (C. reticulate)] were surveyed, and so date palm and ficus trees. However, the results showed that the incidence of this disease was about 100%. Laboratory examinations data revealed mainly two fungal species causing the disease: Physalospora rhodina (P.rhodina) and Diaporthe citri (D. citri). In addition that, both fungi, which are P. rhodina and D. citri affected the vessels of tree tissues. According to the pathogenicity test, the fungus P. rhodina caused a breakdown of parenchyma cells, and the fungus D. citri caused the darkening of the xylem.

Prevalence, identification and frequency of uropathogens causing urinary tract infection in children in Ujjain (M.P.)

: Urinary tract infection is one of the most common infectious disease found in all population and has become a major health problem. The urinary tract infection also affects pediatric population especially in the age group of 0-5 years. The aim of this study to find out prevalence of UTI in children, its occurrence in different gender and seasons along with identification of causative agent of UTI in children in Ujjain. The study was carried out in SRL laboratory Ujjain center and total 881 suspected patients urine sample were collected and tested by conventional methods for prevalence of significant bacteriuria. It was seen that 550 samples were positive and out of these, positive case 111 belonged to children of 0-5 years of age. Thus, 20.18% positive cases were of children. The percentage of UTI in female children was high (54.0%) while in male children it was low (45.9%) and high number of cases were recorded in rainy season (39.6%), followed by summer and winter seasons which were (34.2%) and (26.1%) respectively. The six major uropathogens present in urine sample were isolated and identified and among them four were gram negative in which . , . , . , . were gram negative while and . and . were gram positive UTI causing bacteria in children. In our study frequency of . was highest (60.3%) while . was present in very low frequency (3.6%) so the prevention of UTI in children should be done by proper care of children by mothers.