Morganella morganii, a non-negligent opportunistic pathogen

Delineating the Acquired Genetic Diversity and Multidrug Resistance in Alcaligenes from Poultry Farms and Nearby Soil

Alcaligenes faecalis is one of the most important and clinically significant environmental pathogens, increasing in importance due to its isolation from soil and nosocomial environments. The Gram-negative soil bacterium is associated with skin endocarditis, bacteremia, dysentery, meningitis, endophthalmitis, urinary tract infections, and pneumonia in patients. With emerging antibiotic resistance in A. faecalis, it has become crucial to understand the origin of such resistance genes within this clinically significant environmental and gut bacterium. In this research, we studied the impact of antibiotic overuse in poultry and its effect on developing resistance in A. faecalis. We sampled soil and faecal materials from five poultry farms, performed whole genome sequencing & analysis and identified four strains of A. faecalis. Furthermore, we characterized the genes in the genomic islands of A. faecalis isolates. We found four multidrug-resistant A. faecalis strains that showed resistance against vancomycin (MIC >1000 μg/ml), ceftazidime (50 μg/ml), colistin (50 μg/ml) and ciprofloxacin (50 μg/ml). From whole genome comparative analysis, we found more than 180 resistance genes compared to the reference sequence. Parts of our assembled contigs were found to be similar to different bacteria which included pbp1A and pbp2 imparting resistance to amoxicillin originally a part of Helicobacter and Bordetella pertussis. We also found the Mycobacterial insertion element IS6110 in the genomic islands of all four genomes. This prominent insertion element can be transferred and induce resistance to other bacterial genomes. The results thus are crucial in understanding the transfer of resistance genes in the environment and can help in developing regimes for antibiotic use in the food and poultry industry.

Tracing the possible evolutionary trends of Morganella morganii: insights from molecular epidemiology and phylogenetic analysis

Morganella morganii, encompassing two subspecies, subsp. morganii and subsp. sibonii, is a common opportunistic pathogen, notable for intrinsic resistance to multiple antimicrobial agents. Despite its clinical significance, research into the potential evolutionary dynamics of M. morganii remains limited. This study involved the analysis of genome sequences from 431 M. morganii isolates, comprising 206 isolates that cause host infections, obtained from this study and 225 from the NCBI genome data sets. A diverse array of antimicrobial resistance genes (ARGs) was identified in M. morganii isolates, including mcr-1, tet(X4), tmexCD-toprJ, and various carbapenemase genes. In addition, a novel blaKPC-2-bearing plasmid with demonstrated conjugative capability was discovered in M. morganii. The majority of virulence-related genes (VRGs), except for the hlyCABD gene cluster, were found in almost all M. morganii. Three novel genospecies of M. morganii were identified, designated as M. chanii, M. variant1, and M. variant2. Compared to M. sibonii, M. chanii genospecies possessed a greater number of flagellar-related genes, typically located within mobile genetic elements (MGEs), suggesting potential for better environmental adaptability. Phylogenetic analysis further disclosed that M. morganii was divided into 12 sequence clusters (SCs). Particularly, SC9 harbored an elevated abundance of ARGs and VRGs, mainly toxin-related genes, and was associated with a higher presence of MGEs compared to non-SC9 strains. The collective findings suggest that M. morganii undergoes evolution driven by the influence of MGEs, thereby significantly enhancing its adaptability to selective pressures of environmental changes and clinical antimicrobial agents.IMPORTANCEThe growing clinical significance of Morganella morganii arises from its abundant virulence factors and antimicrobial resistance genes, resulting in elevated infection rates and increased clinical scrutiny. However, research on the molecular epidemiology and evolutionary trends of M. morganii has been scarce. Our study established a list of virulence-related genes (VRGs) for M. morganii and conducted a large-scale epidemiological investigation into these VRGs. Based on genomic classification, three novel genotypes of M. morganii were identified, representing evolutionary adaptations and responses to environmental challenges. Furthermore, we discovered the emergence of a sequence cluster enriched with antimicrobial resistance genes, VRGs, and mobile genetic elements, attributed to the selective pressure of antimicrobial agents. In addition, we identified a novel conjugative plasmid harboring the blaKPC-2 gene. These findings hold significance in monitoring and comprehending the epidemiology of M. morganii.

Spread of carbapenemase-producing Morganella spp from 2013 to 2021: a comparative genomic study

BACKGROUND

Morganella spp are opportunistic pathogens involved in various infections. Intrinsic resistance to multiple antibiotics (including colistin) combined with the emergence of carbapenemase producers reduces the number of active antimicrobials. The aim of this study was to characterise genetic features related to the spread of carbapenem-resistant Morganella spp.

METHODS

This comparative genomic study included extensively drug-resistant Morganella spp isolates collected between Jan 1, 2013, and March 1, 2021, by the French National Reference Center (NRC; n=68) and European antimicrobial resistance reference centres in seven European countries (n=104), as well as one isolate from Canada, two reference strains from the Pasteur Institute collection (Paris, France), and two colistin-susceptible isolates from Bicêtre Hospital (Kremlin-Bicêtre, France). The isolates were characterised by whole-genome sequencing, antimicrobial susceptibility testing, and biochemical tests. Complete genomes from GenBank (n=103) were also included for genomic analysis, including phylogeny and determination of core genomes and resistomes. Genetic distance between different species or subspecies was performed using average nucleotide identity (ANI). Intrinsic resistance mechanisms to polymyxins were investigated by combining genetic analysis with mass spectrometry on lipid A.

FINDINGS

Distance analysis by ANI of 275 isolates identified three groups: Morganella psychrotolerans, Morganella morganii subspecies sibonii, and M morganii subspecies morganii, and a core genome maximum likelihood phylogenetic tree showed that the M morganii isolates can be separated into four subpopulations. On the basis of these findings and of phenotypic divergences between isolates, we propose a modified taxonomy for the Morganella genus including four species, Morganella psychrotolerans, Morganella sibonii, Morganella morganii, and a new species represented by a unique environmental isolate. We propose that M morganii include two subspecies: M morganii subspecies morganii (the most prevalent) and M morganii subspecies intermedius. This modified taxonomy was supported by a difference in intrinsic resistance to tetracycline and conservation of metabolic pathways such as trehalose assimilation, both only present in M sibonii. Carbapenemase producers were mostly identified among five high-risk clones of M morganii subspecies morganii. The most prevalent carbapenemase corresponded to NDM-1, followed by KPC-2, and OXA-48. A cefepime-zidebactam combination was the most potent antimicrobial against the 172 extensively drug-resistant Morganella spp isolates in our collection from different European countries, which includes metallo-β-lactamase producers. Lipid A analysis showed that the intrinsic resistance to colistin was associated with the presence of L-ARA4N on lipid A.

INTERPRETATION

This global characterisation of, to our knowledge, the widest collection of extensively drug-resistant Morganella spp highlights the need to clarify the taxonomy and decipher intrinsic resistance mechanisms, and paves the way for further genomic comparisons.

FUNDING

None.

Isolation and Identification of Morganella morganii from Rhesus Monkey (Macaca mulatta) in China

A bacterium was isolated and identified from the secretion of a rhesus monkey with endometritis. The morphological results showed that the strain exhibited round, convex, gray-white colonies with smooth surfaces and diameters ranging from 1 to 2 mm when cultured on Columbia blood agar at 37 °C for 24 h; on salmonella-shigella agar (S.S.) at 37 °C for 24 h, the colonies appeared round, flat, and translucent. Gram staining showed negative results with blunt ends and non-spore-forming characteristics. Molecular biology results showed that the 16S rRNA sequence of the strain revealed over 96.9% similarity with published sequences of M. morganii from different sources in the NCBI GenBank database. Morphological and molecular biology analysis confirmed that the strain (RM2023) isolated from cervical secretions of rhesus monkey was M. morganii. Drug sensitivity testing demonstrated that the isolated strain (RM2023) was sensitive to ceftriaxone, amikacin, gentamicin, cefazolin, cefuroxime, ceftazidime, levofloxacin, cotrimoxazole, norfloxacin, and tetracycline; moderately sensitive to ampicillin; and resistant to penicillin, vancomycin, ciprofloxacin, and clindamycin. The research findings provide valuable insights for disease prevention in rhesus monkeys and contribute to molecular epidemiological studies.

Hypervirulent Klebsiella pneumoniae Mediated Hepatic Infarction Septic Shock After Rectal Cancer Surgery: A Case Report

The liver receives blood from both the hepatic artery and portal vein. Hepatic infarction is rare in clinical practice as both the hepatic artery and portal vein can supply blood to the liver. Here, we reported a case of a 75-year-old man who underwent radical laparoscopic surgery for rectal cancer and subsequently developed hepatic infarction. The patient experienced severe infection, as well as circulatory and respiratory failure on the third day after surgery. The patient presented with high fever, chest tightness, shortness of breath, decreased blood oxygen saturation and blood pressure. The leukocyte count decreased from 8.10 × 10^9/L to 1.75 × 10^9/L. Procalcitonin (PCT) levels increased from 1.02 ng/mL to 67.14 ng/mL, and eventually reaching levels over 200 ng/mL. Enhanced abdominal computed tomography (CT) confirmed the presence of hepatic infarction, but no thrombosis was observed in the hepatic artery or portal vein. Metagenomic next-generation sequencing (mNGS) identified hypervirulent Klebsiella pneumoniae (hvKp) in the patient's blood and ascites, one day earlier than the detection results using traditional culture methods. The patient was diagnosed with hepatic infarction combined with septic shock caused by hvKp. This case emphasizes that in the high-risk group of thrombosis, infection can trigger exacerbated hepatic infarction events, particularly in cases after surgical procedures. For severely ill patients with infectious diseases who are admitted to the ICU with worsening symptoms, it is important to collect appropriate samples and send them for pathogen detection using mNGS in a timely manner. This may aid in early intervention and improve clinical outcomes.

Venom-microbiomics of eight species of Neotropical spiders from the Theraphosidae family

AIM

Tarantulas are one of the largest predatory arthropods in tropical regions. Tarantulas though not lethal to humans, their venomous bite kills small animals and insect upon which they prey. To understand the abiotic and biotic components involved in Neotropical tarantula bites, we conducted a venom-microbiomics study in eight species from Costa Rica.

METHODS AND RESULTS

We determined that the toxin profiles of tarantula venom are highly diverse using shotgun proteomics; the most frequently encountered toxins were ω-Ap2 toxin, neprilysin-1, and several teraphotoxins. Through culture-independent and culture-dependent methods, we determined the microbiota present in the venom and excreta to evaluate the presence of pathogens that could contribute to primary infections in animals, including humans. The presence of opportunistic pathogens with hemolytic activity was observed, with a prominence of Stenotrophomonas in the venoms. Other bacteria found in venoms and excreta with hemolytic activity included members of the genera Serratia, Bacillus, Acinetobacter, Microbacterium, and Morganella.

CONCLUSIONS

Our data shed light on the venom- and gut-microbiome associated with Neotropical tarantulas. This information may be useful for treating bites from these arthropods in both humans and farm animals, while also providing insight into the toxins and biodiversity of this little-explored microenvironment.

A novel method for enrichment of Morganella morganii in fecal samples using designed culture medium

Morganella morganii is a gram negative, facultative anaerobic rod-shaped bacterium, commonly found in environment and in the intestine of human, mammals, and reptiles as a part of their gut microbiome. M. morganii can cause Gram-negative folliculitis, black nail infection, acute retiform purpura, fetal demise, and subdural empyema. The increasing frequency of M. morganii infections generate the need for efficient methods to enrich the presence of M. morganii in clinical samples to make its detection easier. Culturomics aims to grow and maximize the number of culturable bacteria. Different methods are followed to maximize the growth of minority population of bacteria by disrupting the growth of bacteria which are present in higher concentration. This article presents a method for selective enriching the M. morganii in human fecal samples. This method includes prior incubation of fecal microbiota in an anaerobic environment, adding supplement like fecal water to give dormant bacteria a break to become active to grow to threshold concentration, and an enrichment stage which provides the additional opportunity of growing to M. morganii on the selective medium. This method also provides an ingenuous way for augmenting the growth of fecal M. morganii species.

Clonal relationship, virulence genes, and antimicrobial resistance of Morganella morganii isolated from community-acquired infections and hospitalized patients: a neglected opportunistic pathogen

Morganella morganii is a bacterium belonging to the normal intestinal microbiota and the environment; however, in immunocompromised individuals, this bacterium can become an opportunistic pathogen, causing a series of diseases, both in hospitals and in the community, being urinary tract infections more prevalent. Therefore, the objective of this study was to evaluate the prevalence, virulence profile, and resistance to antimicrobials and the clonal relationship of isolates of urinary tract infections (UTI) caused by M. morganii, both in the hospital environment and in the community of the municipality of Londrina-PR, in southern Brazil, in order to better understand the mechanisms for the establishment of the disease caused by this bacterium. Our study showed that M. morganii presents a variety of virulence factors in the studied isolates. Hospital strains showed a higher prevalence for the virulence genes zapA, iutA, and fimH, while community strains showed a higher prevalence for the ireA and iutA genes. Hospital isolates showed greater resistance compared to community isolates, as well as a higher prevalence of multidrug-resistant (MDR) and extended-spectrum beta lactamase (ESBL)-producing isolates. Several M. morganii isolates from both sources showed high genetic similarity. The most prevalent plasmid incompatibility groups detected were FIB and I1, regardless of the isolation source. Thus, M. morganii isolates can accumulate virulence factors and antimicrobial resistance, making them a neglected opportunistic pathogen.

Draft genome sequences of four Morganella morganii strains isolated from Colombian colorectal cancer patient stool specimens

We report the draft genome sequences of four Morganella morganii strains isolated from the stools of four patients diagnosed with colorectal cancer (CRC) in Medellín, Colombia. These genomes represent an important addition to the limited number of genomes of M. morganii strains originating from CRC patients currently available.

Pectoralis Major Pyomyositis in a Patient With Diabetes: A Case Report and Literature Review

Pyogenic myositis is a bacterial infection of skeletal muscle that is usually caused by Staphylococcus aureus and is common in tropical regions. Recently, this infection has also been reported in immunocompromised patients in temperate regions. The lower extremities and trunk are most affected, while involvement of the chest wall is rare. We report a case of pectoralis major pyomyositis caused by Morganella morganii in an 82-year-old Japanese man with type 2 diabetes mellitus who had undergone stenting for myocardial infarction. Four months prior to visiting our hospital, the patient became aware of pain in the right chest area, which gradually became swollen. One month before the visit, the pain and swelling had become more severe. At the visit, there was swelling in the right anterior thoracic region with a diameter of 10 cm and pain in the same region. On physical examination, his blood pressure was 133/64 mmHg, heart rate was 83 beats/min, and body temperature was 36.9℃. Initially, a sarcoma or other neoplastic lesion was suspected and a needle biopsy was performed. Pus was drained from the puncture site to collect wound culture. Needle biopsy of the lesion did not reveal any fungi or acid-fast bacteria, and a T-SPOT.TB test was negative. Computed tomography and magnetic resonance imaging suggested abscess formation under the pectoralis major muscle. A wound culture test detected Morganella morganii, and pectoralis major pyomyositis was diagnosed. Debridement was performed under general anesthesia. The necrotic pectoralis major muscle was excised, the abscess cavity was opened, and wound irrigation was performed. The postoperative course was good and the patient was discharged on the 16th postoperative day. There has been no recurrence in eight months postoperatively. Pectoralis major pyomyositis may not be relieved by antibiotics alone and may extend to deeper organs to form intrapleural abscesses. Therefore, prompt drainage should be performed to prevent serious complications in a case in which abscess formation is observed.

Development of pharmacophore models for AcrB protein and the identification of potential adjuvant candidates for overcoming efflux-mediated colistin resistance

Growing multi-drug resistance (MDR) among ESKAPE pathogens is a huge challenge. Increased resistance to last-resort antibiotics, like colistin, has further aggravated this. Efflux is identified as a major route of colistin resistance. So, finding an FDA-approved efflux inhibitor for potential application as an adjuvant to colistin was the primary objective of this study. E. coli-AcrB pump inhibitors and substrates were used to develop and validate the pharmacophoric model. Drugs confirming this pharmacophore were subjected to molecular docking to identify hits for the AcrB binding pocket. The efflux inhibition potential of the top hit was validated through the in vitro evaluation of the minimum inhibitory concentration (MIC) in combination with colistin. The checkerboard assay was done to demonstrate synergism, which was further corroborated by the Time-kill assay. Ten common pharmacophore hypotheses were successfully generated using substrate/inhibitors. Following enrichment analysis, AHHNR.100 was identified as the top-ranked hypothesis, and 207 unique compounds were found to conform to this hypothesis. The multi-step docking of these compounds against the AcrB protein revealed argatroban as the top non-antibiotic hit. This significantly inhibited the efflux activity of colistin-resistant clinical isolates K. pneumoniae (n = 1) and M. morganii (n = 2). Further, their combination with colistin enhanced the susceptibility of these isolates, and the effect was found to be synergistic. Accordingly, the time-kill assay of this combination showed 8-log and 2-log reductions against K. pneumoniae and M. morganii, respectively. In conclusion, this study found argatroban as a bacterial efflux inhibitor that can be potentially used to overcome efflux-mediated resistance.

In Vivo Wound Healing in Drosophila melanogaster and Mouse Models: Synergistic Effect of Bovine Serum Albumin and Graphene Quantum Dots

Bovine serum albumin (BSA)-based biomaterials have garnered significant attention for their remarkable potential in wound healing, primarily due to their effective biological actions in addressing the skin inflammation phase and mitigating hypoalbuminemia. Motivated by these attributes, a nanocomposite hydrogel is developed by blending BSA with poly(vinyl alcohol) (PVA), complemented by the incorporation of graphene quantum dot (GQD). The FTIR study establishes a hydrogen-bonding interaction between the -NH2 groups of BSA and the -OH group of PVA. Microscopic investigations establish that the dispersion of GQDs with an average size of 22.5 nm results in smoothening of the surface of the nanocomposite. The nanocomposite hydrogel reveals excellent swelling attributes of about 920% in a period of 6 h due to its optimum cross-linking condition. Furthermore, the hydrogel exhibits a water vapor transmission rate of 8.45 mg cm-2 h-1, akin to the transmission rate of wounded skin. The PVA/BSA@GQD nanocomposite's antibacterial efficacy is evaluated against Morganella morganii bacteria, showing 99% killing, while its cytotoxicity assay against HeLa cells exhibited a minimum cell viability of 76% at a 20 μM concentration, which is ideal for a wound dressing material. In vivo wound healing investigations are conducted on Drosophila, showcasing a 100% wound surface closure within 4 h. This outcome is further substantiated through in vivo studies involving mice, where complete re-epithelialization is achieved within a span of 13 days. The combined results establish the PVA/BSA@GQD nanocomposite as a potential wound dressing material.

Features of Hemolysin Biosynthesis by Morganella morganii

We studied the influence of medium composition and aeration on the hemolytic activity of uropathogenic Morganella morganii strain MM 190. The maximum level of hemolysis was observed in LB (59%), DMEM supplemented with fetal bovine serum (62%), and urine (53%) under aeration conditions during the exponential growth phase. The presence of 2% urea in the medium suppressed hemolysin synthesis. Moreover, addition of bacterial culture fluid containing hemolysin to a monolayer of T-24 bladder carcinoma and OKP-GS kidney carcinoma cells led to 25 and 42% cell death, respectively. We found that the maximum expression of the hemolysin gene hlyA was observed in 2-h culture in LB medium, which correlated with the hemolytic activity of the bacteria in this medium and indicated the predominance of the short hlyCA transcript in the cells.

Antimicrobial Resistance in Papua New Guinea: A Narrative Scoping Review

Antimicrobial-resistant bacterial infections are a known threat to the public health of low-income countries and are undercharacterized in Papua New Guinea. A scoping literature review of scientific peer-reviewed publications on antimicrobial resistance in Papua New Guinea was conducted, and their results were summarized. Many of the available data on resistant bacteria in Papua New Guinea have come from Port Moresby and Goroka and have been focused on Staphylococcus aureus, as well as important pediatric pathogens such as Streptococcus pneumoniae and Haemophilus influenzae. Progressive resistance to the commonly used antibiotics penicillin and chloramphenicol among most clinically important bacterial pathogens has prompted healthcare workers to adopt expensive broad-spectrum antibiotics. There is already evidence of resistance to newly adopted antibiotics among several Gram-negative organisms. Drivers of antimicrobial resistance in Papua New Guinea include a high burden of infectious diseases, inappropriate antibiotic prescription practices, poor regulation of antibiotics, incomplete adherence, substandard drug quality, and overcrowding of healthcare facilities. There is a lack of information on antimicrobial resistance among priority pathogens and from several important regions of Papua New Guinea.

Morganella morganii and Enterococcus faecalis endophthalmitis following intravitreal injection

BACKGROUND

Endophthalmitis following intravitreal injection is a potentially devastating complication of anti-VEGF injections. Post-injection endophthalmitis due to Enterococcus faecalis is rare, and no previous case of Morganella morganii endophthalmitis after intravitreal injection has been reported.

CASE PRESENTATION

We present the first reported case of Morganella morganii and Enterococcus faecalis endophthalmitis after intravitreal injection in an immunocompetent patient in the absence of recent ocular surgery. Our patient presented with hand movement visual acuity one day after anti-VEGF injection and demonstrated no clinical improvement despite repeated intravitreal ceftazidime and vancomycin injections. A decision was made to proceed with early vitrectomy given failure of intravitreal antibiotics. Visual acuity improved to 6/90 at 12 weeks after vitrectomy without any evidence of disease recurrence.

CONCLUSIONS

Post-injection endophthalmitis due to concurrent Morganella morganii and Enterococcus faecalis infections can have visually devastating consequences despite repeated empirical and targeted intravitreal antibiotics. Lack of clinical improvement following intravitreal antibiotics should warrant consideration of early vitrectomy. Our experience is a pertinent reminder of the ever-growing threat of uncommon and multi-resistant bacteria that must be considered when treating infections such as post-injection endophthalmitis.

Occurrence of mcr genes and alterations in mgrB gene in intrinsic colistin- resistant Enterobacterales isolated from chicken meat samples

BACKGROUND

Tolerance of gram negative pathogens toward last resort colistin is mediated by mcr genes and alterations in chromosomal mgrB via modification of lipopolysaccharide through the PmrAB and PhoPQ component system. Proteus sp., Morganella sp., Neisseria sp., Burkholderia sp. and Providencia sp. are intrinsic resistant to colistin drug. Recent reports have shown that colistin intrinsic resistant organisms harbor and act as reservoirs for mcr genes.

AIM

To evaluate the presence of mcr-1 to mcr-5 genes and alterations in mgrB gene in intrinsic colistin-resistant gram negative bacteria isolated from chicken meat samples in Coimbatore district, Tamil Nadu, India.

METHODS

One hundred chicken meat samples were collected during 2019-20. Samples were enriched and plated on MacConkey agar supplemented with colistin (2 μg/ml). The bacterial isolates were then identified using biochemical tests. DNA were extracted from isolates using the thermal lysis method. mcr-1 to mcr-5 and mgrB genes was detected using conventional PCR and agarose gel electrophoresis methods.

RESULT AND CONCLUSION

The presence of mcr-1 to mcr-5 genes was found to be 23 % (23/100). mcr-1 and mcr-5 genes were not detected in sample isolates. 17/23 samples positive for mcr genes were also found to be carrying alterations in mgrB gene. Phenotypic characterization of these isolates revealed that these bacteria were belonging to colistin intrinsic resistant gram negative bacteria such as Proteus sp., Providencia sp., and Morganella sp. Intrinsic resistant bacteria could act as a potential reservoir and disseminate mcr genes to the colistin sensitive non-intrinsic pathogens of clinical importance in the environment.

Antimicrobial Susceptibility Trends of Proteeae Isolates From a Tertiary-Care Hospital in Western Saudi Arabia

BACKGROUND

The tribe Proteeae comprises Proteus, Providencia, and Morganella species. TheseGram-negative rods are of concern in that they are involved in diverse human infections, particularly in hospital settings. In the last two decades, there has been a sharp increase in infections by multidrug-resistant (MDR) Proteeae. Therefore, the objectives of this study were to: (i) assess the prevalence of infections caused by tribe Proteeae, (ii)determine the antimicrobial susceptibility profile of the test isolates, and (iii) identify the underlying risk factors for acquisition of infection by MDR strains.

METHODS

During the period from January 2019 to December 2020, we conducted a retrospective review of the electronic medical and laboratory records of adult patients who received care at our institution. In addition, we analyzed the risk factors associated with acquisition of infections by members of the tribe Proteeae using univariate and multivariate regression models.

RESULTS

Overall 403 adult patients (average age 59.69 ± 20.33 years) were enrolled into this study (196 males; 48.6%, and 207 females; 51.4%). Proteus mirabilis was the leading pathogen (70.7%; n=285), followed by Morganella morganii (20.1%; n=81), and Providencia species (9.2%; n=37). Most of the isolates were recovered from urine (59.3%; n=239), followed by wound swabs (23.1%; n=93), with the least from blood samples (1.7%; n=7). Out of 403 Proteeae isolates, 27.3% (n=110) were found to be extended-spectrum β-lactamase (ESBL)-producers, whereas 18.4% (n=74) were MDR. Patient's age, concomitant diabetes mellitus (DM), and long hospital stays were independently associated with infection by MDR strains.

CONCLUSION

Infections by MDR Proteeae are leading causes for morbidity in our tertiary-care facility. Strict adherence to infection control precautions, as well as effective implementation of antimicrobial stewardship programs, are crucial to overcome these superbugs.

Comparisons of the Oral Microbiota from Seven Species of Wild Venomous Snakes in Taiwan Using the High-Throughput Amplicon Sequencing of the Full-Length 16S rRNA Gene

A venomous snake's oral cavity may harbor pathogenic microorganisms that cause secondary infection at the wound site after being bitten. We collected oral samples from 37 individuals belonging to seven species of wild venomous snakes in Taiwan, including Naja atra (Na), Bungarus multicinctus (Bm), Protobothrops mucrosquamatus (Pm), Trimeresurus stejnegeri (Ts), Daboia siamensis (Ds), Deinagkistrodon acutus (Da), and alpine Trimeresurus gracilis (Tg). Bacterial species were identified using full-length 16S rRNA amplicon sequencing analysis, and this is the first study using this technique to investigate the oral microbiota of multiple Taiwanese snake species. Up to 1064 bacterial species were identified from the snake's oral cavities, with 24 pathogenic and 24 non-pathogenic species among the most abundant ones. The most abundant oral bacterial species detected in our study were different from those found in previous studies, which varied by snake species, collection sites, sampling tissues, culture dependence, and analysis methods. Multivariate analysis revealed that the oral bacterial species compositions in Na, Bm, and Pm each were significantly different from the other species, whereas those among Ts, Ds, Da, and Tg showed fewer differences. Herein, we reveal the microbial diversity in multiple species of wild snakes and provide potential therapeutic implications regarding empiric antibiotic selection for wildlife medicine and snakebite management.

Deciphering the functional diversity of the gut microbiota of the black soldier fly (Hermetia illucens): recent advances and future challenges

Bioconversion using insects is a promising strategy to convert organic waste (catering leftovers, harvest waste, food processing byproducts, etc.) into biomass that can be used for multiple applications, turned into high added-value products, and address environmental, societal and economic concerns. Due to its ability to feed on a tremendous variety of organic wastes, the black soldier fly (Hermetia illucens) has recently emerged as a promising insect for bioconversion of organic wastes on an industrial scale. A growing number of studies have highlighted the pivotal role of the gut microbiota in the performance and health of this insect species. This review aims to provide a critical overview of current knowledge regarding the functional diversity of the gut microbiota of H. illucens, highlighting its importance for bioconversion, food safety and the development of new biotechnological tools. After providing an overview of the different strategies that have been used to outline the microbial communities of H. illucens, we discuss the diversity of these gut microbes and the beneficial services they can provide to their insect host. Emphasis is placed on technical strategies and aspects of host biology that require special attention in the near future of research. We also argue that the singular digestive capabilities and complex gut microbiota of H. illucens make this insect species a valuable model for addressing fundamental questions regarding the interactions that insects have evolved with microorganisms. By proposing new avenues of research, this review aims to stimulate research on the microbiota of a promising insect to address the challenges of bioconversion, but also fundamental questions regarding bacterial symbiosis in insects.

Isoniazid Mono-Resistant Tuberculosis Presenting as Empyema Thoracis With Citrobacter koseri and Morganella morganii Infections: The World's First Reported Case of Its Type

Drug resistance is very common in developing countries. Isolated cases of concomitant infection with Mycobacterium tuberculosis, Citrobacter koseri, and Morganella morganii are rare. Furthermore, there is no report available in the literature of concurrent infection of Citrobacter koseri and Morganella morganii in an isoniazid mono-resistant tuberculosis patient. In this case, we present a concomitant infection with drug-resistant strains of Mycobacterium tuberculosis, Citrobacter koseri, and Morganella morganii in a 40-year-old Indian male who presented with fever, dry cough, and chest pain. He was initiated on an isoniazid mono regimen and a broad-spectrum antibiotic, following the national guidelines.

Sequencing and Characterization of M. morganii Strain UM869: A Comprehensive Comparative Genomic Analysis of Virulence, Antibiotic Resistance, and Functional Pathways

Morganella morganii is a Gram-negative opportunistic Enterobacteriaceae pathogen inherently resistant to colistin. This species causes various clinical and community-acquired infections. This study investigated the virulence factors, resistance mechanisms, functional pathways, and comparative genomic analysis of M. morganii strain UM869 with 79 publicly available genomes. The multidrug resistance strain UM869 harbored 65 genes associated with 30 virulence factors, including efflux pump, hemolysin, urease, adherence, toxin, and endotoxin. Additionally, this strain contained 11 genes related to target alteration, antibiotic inactivation, and efflux resistance mechanisms. Further, the comparative genomic study revealed a high genetic relatedness (98.37%) among the genomes, possibly due to the dissemination of genes between adjoining countries. The core proteome of 79 genomes contains the 2692 core, including 2447 single-copy orthologues. Among them, six were associated with resistance to major antibiotic classes manifested through antibiotic target alteration (PBP3, gyrB) and antibiotic efflux (kpnH, rsmA, qacG; rsmA; CRP). Similarly, 47 core orthologues were annotated to 27 virulence factors. Moreover, mostly core orthologues were mapped to transporters (n = 576), two-component systems (n = 148), transcription factors (n = 117), ribosomes (n = 114), and quorum sensing (n = 77). The presence of diversity in serotypes (type 2, 3, 6, 8, and 11) and variation in gene content adds to the pathogenicity, making them more difficult to treat. This study highlights the genetic similarity among the genomes of M. morganii and their restricted emergence, mostly in Asian countries, in addition to their growing pathogenicity and resistance. However, steps must be taken to undertake large-scale molecular surveillance and to direct suitable therapeutic interventions.

Microbiological safety and quality of ceviche, poke, and sushi dishes sold at retail outlets in Orange County, CA

Raw, ready-to-eat (RTE) seafood products, such as ceviche, poke, and sushi, have experienced growing demand globally; however, these products have the potential to be contaminated with foodborne pathogens. The objective of this study was to determine the prevalence of Escherichiacoli/coliforms, Salmonella, and Listeria in ceviche, poke, and sushi dishes sold at the retail level in Orange County, CA, USA. Additional organisms detected during testing were also considered in the results. A total of 105 raw, RTE samples of ceviche, poke, and sushi were collected from restaurants and grocery stores in Orange County, CA. Samples were tested for Salmonella and Listeria utilizing methods from the Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM). E. coli and total coliforms were enumerated utilizing 3 M Petrifilm plates. Overall, two samples (1.9%) were positive for generic E. coli, with a range of 5-35 CFU/g. Coliforms were detected in 85 samples (81%), with a range of 5-1710 CFU/g. The average coliform levels in ceviche samples (259 CFU/g) were significantly higher than the levels in sushi samples (95 CFU/g), according to a Kruskal-Wallis H test followed by the Dunn test (p < 0.05). The coliform levels in poke samples (196 CFU/g) were not significantly different from those in ceviche or sushi. All levels of E. coli and coliforms were considered acceptable or satisfactory/borderline according to standards for RTE seafood. None of the samples tested positive for Salmonella or Listeria monocytogenes; however, other microorganisms were detected in 17 samples, including Listeria spp., Proteus mirabilis, Providencia rettgeri, and Morganella morganii. The results of this study are novel in that they present data on the microbiological safety and quality of ceviche, poke, and sushi dishes sold at retail in the United States, as well as provide a comparison across the three categories of raw, RTE seafood.

Altered gut microbiota in temporal lobe epilepsy with anxiety disorders

Introduction

Patients with epilepsy are particularly vulnerable to the negative effects of anxiety disorders. In particular, temporal lobe epilepsy with anxiety disorders (TLEA) has attracted more attention in epilepsy research. The link between intestinal dysbiosis and TLEA has not been established yet. To gain deeper insight into the link between gut microbiota dysbiosis and factors affecting TLEA, the composition of the gut microbiome, including bacteria and fungi, has been examined.

Methods

The gut microbiota from 51 temporal lobe epilepsy patients has been subjected to sequencing targeting 16S rDNA (Illumina MiSeq) and from 45 temporal lobe epilepsy patients targeting the ITS-1 region (through pyrosequencing). A differential analysis has been conducted on the gut microbiota from the phylum to the genus level.

Results

TLEA patients' gut bacteria and fungal microbiota exhibited distinct characteristics and diversity as evidenced by high-throughput sequencing (HTS). TLEA patients showed higher abundances of Escherichia-Shigella (genus), Enterobacterales (order), Enterobacteriaceae (family), Proteobacteria (phylum), Gammaproteobacteria (class), and lower abundances of Clostridia (class), Firmicutes, Lachnospiraceae (family), Lachnospirales (order), and Ruminococcus (genus). Among fungi, Saccharomycetales fam. incertae sedis (family), Saccharomycetales (order), Saccharomycetes (class), and Ascomycota (phylum) were significantly more abundant in TLEA patients than in patients with temporal lobe epilepsy but without anxiety. Adoption and perception of seizure control significantly affected TLEA bacterial community structure, while yearly hospitalization frequency affected fungal community structures in TLEA patients.

Conclusion

Here, our study validated the gut microbiota dysbiosis of TLEA. Moreover, the pioneering study of bacterial and fungal microbiota profiles will help in understanding the course of TLEA and drive us toward preventing TLEA gut microbiota dysbiosis.

Glabridin inhibited the spread of polymyxin-resistant Enterobacterium carrying ICEMmoMP63

Introduction

The role of integrative and conjugative elements (ICEs) in antibiotic resistance in Morganella morganii is unknown. This study aimed to determine whether an ICE identified in the M. morganii genome contributed to the polymyxin resistance.

Methods

Whole-genome sequencing was performed followed by bioinformatics analyses to identify ICEs and antibiotic resistance genes. Conjugation assays were performed to analyze the transferability of a discovered ICE. A drug transporter encoded on the ICE was heterogeneously expressed in Escherichia coli, minimum inhibitory concentrations of antibiotics were determined, and a traditional Chinese medicine library was screened for potential efflux pump inhibitors.

Results

An antibiotic resistance-conferring ICE, named ICEMmoMP63, was identified. ICEMmoMP63 was verified to be horizontally transferred among Enterobacteriaceae bacteria. G3577_03020 in ICEMmoMP63 was found to mediate multiple antibiotic resistances, especially polymyxin resistance. However, natural compound glabridin was demonstrated to inhibit polymyxin resistance.

Discussion

Our findings support the need for monitoring dissemination of ICEMmoMP63 in Enterobacteriaceae bacteria. Combined glabridin and polymyxin may have therapeutic potential for treating infections from multi-drug resistant bacteria carrying ICEMmoMP63.

Antimicrobial Resistance in Romania: Updates on Gram-Negative ESCAPE Pathogens in the Clinical, Veterinary, and Aquatic Sectors

Multidrug-resistant Gram-negative bacteria such as Acinetobacter baumannii, Pseudomonas aeruginosa, and members of the Enterobacterales order are a challenging multi-sectorial and global threat, being listed by the WHO in the priority list of pathogens requiring the urgent discovery and development of therapeutic strategies. We present here an overview of the antibiotic resistance profiles and epidemiology of Gram-negative pathogens listed in the ESCAPE group circulating in Romania. The review starts with a discussion of the mechanisms and clinical significance of Gram-negative bacteria, the most frequent genetic determinants of resistance, and then summarizes and discusses the epidemiological studies reported for A. baumannii, P. aeruginosa, and Enterobacterales-resistant strains circulating in Romania, both in hospital and veterinary settings and mirrored in the aquatic environment. The Romanian landscape of Gram-negative pathogens included in the ESCAPE list reveals that all significant, clinically relevant, globally spread antibiotic resistance genes and carrying platforms are well established in different geographical areas of Romania and have already been disseminated beyond clinical settings.

Shotgun Proteomics Analysis, Functional Networks, and Peptide Biomarkers for Seafood-Originating Biogenic-Amine-Producing Bacteria

Biogenic amine-producing bacteria are responsible for the production of basic nitrogenous compounds (histamine, cadaverine, tyramine, and putrescine) following the spoilage of food due to microorganisms. In this study, we adopted a shotgun proteomics strategy to characterize 15 foodborne strains of biogenic-amine-producing bacteria. A total of 10,673 peptide spectrum matches belonging to 4081 peptides and corresponding to 1811 proteins were identified. Relevant functional pathways were determined, and strains were differentiated into hierarchical clusters. An expected protein-protein interaction network was created (260 nodes/1973 interactions). Most of the determined proteins were associated with networks/pathways of energy, putrescine metabolism, and host-virus interaction. Additionally, 556 peptides were identified as virulence factors. Moreover, 77 species-specific peptide biomarkers corresponding to 64 different proteins were proposed to identify 10 bacterial species. This represents a major proteomic dataset of biogenic-amine-producing strains. These results may also be suitable for new treatments for food intoxication and for tracking microbial sources in foodstuffs.

Evidence for wastewaters as environments where mobile antibiotic resistance genes emerge

The emergence and spread of mobile antibiotic resistance genes (ARGs) in pathogens have become a serious threat to global health. Still little is known about where ARGs gain mobility in the first place. Here, we aimed to collect evidence indicating where such initial mobilization events of clinically relevant ARGs may have occurred. We found that the majority of previously identified origin species did not carry the mobilizing elements that likely enabled intracellular mobility of the ARGs, suggesting a necessary interplay between different bacteria. Analyses of a broad range of metagenomes revealed that wastewaters and wastewater-impacted environments had by far the highest abundance of both origin species and corresponding mobilizing elements. Most origin species were only occasionally detected in other environments. Co-occurrence of origin species and corresponding mobilizing elements were rare in human microbiota. Our results identify wastewaters and wastewater-impacted environments as plausible arenas for the initial mobilization of resistance genes.

Systemic antibiotics increase microbiota pathogenicity and oral bone loss

Periodontitis is the most widespread oral disease and is closely related to the oral microbiota. The oral microbiota is adversely affected by some pharmacologic treatments. Systemic antibiotics are widely used for infectious diseases but can lead to gut dysbiosis, causing negative effects on the human body. Whether systemic antibiotic-induced gut dysbiosis can affect the oral microbiota or even periodontitis has not yet been addressed. In this research, mice were exposed to drinking water containing a cocktail of four antibiotics to explore how systemic antibiotics affect microbiota pathogenicity and oral bone loss. The results demonstrated, for the first time, that gut dysbiosis caused by long-term use of antibiotics can disturb the oral microbiota and aggravate periodontitis. Moreover, the expression of cytokines related to Th17 was increased while transcription factors and cytokines related to Treg were decreased in the periodontal tissue. Fecal microbiota transplantation with normal mice feces restored the gut microbiota and barrier, decreased the pathogenicity of the oral microbiota, reversed the Th17/Treg imbalance in periodontal tissue, and alleviated alveolar bone loss. This study highlights the potential adverse effects of long-term systemic antibiotics-induced gut dysbiosis on the oral microbiota and periodontitis. A Th17/Treg imbalance might be related to this relationship. Importantly, these results reveal that the periodontal condition of patients should be assessed regularly when using systemic antibiotics in clinical practice.

A Rare Case of Fulminant Acute Postoperative Morganella morganii Endophthalmitis

PURPOSE

The authors present a case of a 60-year-old Indian female presented with sudden loss of vision in the right eye three days after an uneventful cataract surgery which revealed a rare organism and which was treated successfully.

METHODS

She was diagnosed with acute postoperative endophthalmitis with fulminant disease and on further work up, culture showed Morganella morganii (gram negative bacilli).

RESULTS

She was successfully treated with intravitreal imipenem, dexamethasone and vitrectomy. A review of literature was conducted to identify and discuss additional reports on similar cases. As per PubMed search with keywords "Morganella morganii endophthalmitis" this is the best achieved visual outcome to date in a case of acute post-operative Morganella morganii endophthalmitis.

CONCLUSION

Intravitreal imipenem can be considered to treat Morganella morganii endophthalmitis. Aggressive treatment in these patients can help in improving visual outcome.

Pathometagenomics reveals susceptibility to intestinal infection by Morganella to be mediated by the blood group-related B4galnt2 gene in wild mice

Infectious disease is widely considered to be a major driver of evolution. A preponderance of signatures of balancing selection at blood group-related genes is thought to be driven by inherent trade-offs in susceptibility to disease. B4galnt2 is subject to long-term balancing selection in house mice, where two divergent allele classes direct alternative tissue-specific expression of a glycosyltransferase in the intestine versus blood vessels. The blood vessel allele class leads to prolonged bleeding times similar to von Willebrand disease in humans, yet has been maintained for millions of years. Based on in vivo functional studies in inbred lab strains, it is hypothesized that the cost of prolonged bleeding times may be offset by an evolutionary trade-off involving susceptibility to a yet unknown pathogen(s). To identify candidate pathogens for which resistance could be mediated by B4galnt2 genotype, we here employed a novel "pathometagenomic" approach in a wild mouse population, which combines bacterial 16S rRNA gene-based community profiling with histopathology of gut tissue. Through subsequent isolation, genome sequencing and controlled experiments in lab mice, we show that the presence of the blood vessel allele is associated with resistance to a newly identified subspecies of Morganella morganii, a clinically important opportunistic pathogen. Given the increasing importance of zoonotic events, the approach outlined here may find useful application in the detection of emerging diseases in wild animal populations.

Tibial Osteomyelitis Caused by Morganella morganii After External Fixation for Limb Length Discrepancy in a Pediatric Patient: A Case Report and Literature Review

Morganella morganii is a facultative, anaerobic rod Gram-negative enteric bacterium. Few cases are documented of musculoskeletal infection. We present a case of a 9-year-old boy with osteomyelitis 1 year after index external fixation for leg length discrepancy. Our patient initially presented with wound drainage at his distal medial tibia fixation site but had negative radiographs. Initial antibiotic treatment failed after 1-month follow-up, and cultures revealed M. morganii. He underwent incision and drainage with external fixator removal, and the antibiotic regimen changed after a susceptibility panel. Symptoms were alleviated after 30 days with the new antibiotic regimen, and the patient was put back on his original schedule for limb lengthening through external fixation. A new methicillin-sensitive Staphylococcus aureus occurred at the same site 2.5 years later but was easily treated, and the 3-year follow-up showed no other recurrences or complications.

Microbial diversity and antimicrobial susceptibility in endotracheal tube biofilms recovered from mechanically ventilated COVID-19 patients

In patients with acute respiratory failure, mechanical ventilation through an endotracheal tube (ET) may be required to correct hypoxemia and hypercarbia. However, biofilm formation on these ETs is a risk factor for infections in intubated patients, as the ET can act as a reservoir of microorganisms that can cause infections in the lungs. As severely ill COVID-19 patients often need to be intubated, a better knowledge of the composition of ET biofilms in this population is important. In Spring 2020, during the first wave of the COVID-19 pandemic in Europe, 31 ETs were obtained from COVID-19 patients at Ghent University Hospital (Ghent, Belgium). Biofilms were collected from the ET and the biofilm composition was determined using culture-dependent (MALDI-TOF mass spectrometry and biochemical tests) and culture-independent (16S and ITS1 rRNA amplicon sequencing) approaches. In addition, antimicrobial resistance was assessed for isolates collected via the culture-dependent approach using disc diffusion for 11 antimicrobials commonly used to treat lower respiratory tract infections. The most common microorganisms identified by the culture-dependent approach were those typically found during lung infections and included both presumed commensal and potentially pathogenic microorganisms like Staphylococcus epidermidis, Enterococcus faecalis, Pseudomonas aeruginosa and Candida albicans. More unusual organisms, such as Paracoccus yeei, were also identified, but each only in a few patients. The culture-independent approach revealed a wide variety of microbes present in the ET biofilms and showed large variation in biofilm composition between patients. Some biofilms contained a diverse set of bacteria of which many are generally considered as non-pathogenic commensals, whereas others were dominated by a single or a few pathogens. Antimicrobial resistance was widespread in the isolates, e.g. 68% and 53% of all isolates tested were resistant against meropenem and gentamicin, respectively. Different isolates from the same species recovered from the same ET biofilm often showed differences in antibiotic susceptibility. Our data suggest that ET biofilms are a potential risk factor for secondary infections in intubated COVID-19 patients, as is the case in mechanically-ventilated non-COVID-19 patients.

Microbial Interdomain Interactions Delineate the Disruptive Intestinal Homeostasis in Clostridioides difficile Infection

Clostridioides difficile infection (CDI) creates an imbalance in the intestinal microbiota due to the interaction of the components making up this ecosystem, but little is known about the impact of this disease on other microbial members. This work has thus been aimed at evaluating the taxonomic composition, potential gene-associated functions, virulence factors, and antimicrobial resistance profiles of gut microbiomes. A total of 48 DNA samples obtained from patients with health care facility-acquired (HCFO) and community-onset (CO) diarrhea were distributed in the following four groups according to CDI status: HCFO/+ (n = 13), HCFO/- (n = 8), CO/+ (n = 13), and CO/- (n = 14). These samples were subjected to shotgun metagenomics sequencing. Although the CDI groups' microbiota had microbiome alterations, the greatest imbalance was observed in the in the HCFO+/- groups, with an increase in common pathogens and phage populations, as well as a decrease in beneficial microorganisms that leads to a negative impact on some intestinal homeostasis-related metabolic processes. A reduction in the relative abundance of butyrate metabolism-associated genes was also detected in the HCFO groups (P < 0.01), with an increase in some virulence factors and antibiotic-resistance markers. A set of 51 differentially abundant species in the groups with potential association to CDI enabled its characterization, leading to their spatial separation by onset. Strong correlations between phages and some archaeal and bacterial phyla were identified. This highlighted the need to study the microbiota's various components since their imbalance is multifactorial, with some pathogens contributing to a greater or lesser extent because of their interaction with the ecosystem they inhabit. IMPORTANCE Clostridioides difficile infection represents a serious public health problem in different countries due to its high morbi-mortality and the high costs it represents for health care systems. Studies have shown the impact of this infection on intestinal microbiome homeostasis, mainly on bacterial populations. Our research provides evidence of the impact of CDI at both the compositional (bacteria, archaea, and viruses), and functional levels, allowing us to understand that the alterations of the microbiota occur systemically and are caused by multiple perturbations generated by different members of the microbiota as well as by some pathogens that take advantage of the imbalance to proliferate. Likewise, the 51 differentially abundant species in the study groups with potential association to CDI found in this study could help us envisage future treatments against this and other inflammatory diseases, improving future therapeutic options for patients.

Colorimetric Detection of Urease-Producing Microbes Using an Ammonia-Responsive Flexible Film Sensor

Urease-producing (ureolytic) microbes have given rise to environmental and public health concerns because they are thought to contribute to emissions of ammonia and to be a virulence factor for infections. Therefore, it is highly important to have the ability to detect such microbes. In this study, a poly(dimethylsiloxane) (PDMS)-based colorimetric film sensor was employed for the detection of urease-producing microbes. The sensor was able to detect the enzyme activity of commercially available urease, as the color and absorbance spectrum of the sensor was observed to change upon being exposed to the reaction catalyzed by urease. The ratio of the absorbance of the sensor at 640 nm to that at 460 nm (A₆₄₀/A₄₆₀) was linearly proportional to the amount of urease present. The performance of the sensor was validated by the results of a sensitivity and selectivity analysis towards thirteen different bacterial strains. Based on the development of blue color of the sensor, the tested bacteria were classified as strongly positive, moderately positive, weakly positive, or negative urease producers. The response of the sensor to ureolytic bacteria was verified using the urease inhibitor phenyl phosphorodiamidate (PPDA). Additionally, the sensor achieved the selective detection of ureolytic bacteria even in the presence of non-ureolytic bacteria. In addition, a used sensor could be reverted to its original state by being subjected to simple aeration, and in this way the same sensor could be used at least five times for the detection of bacterial urease activity.

Morganella Morganii Infection in Hirudo Medicinalis (Iran): A Case Report

Simple Summary

Morganella morganii is a motile, non-spore-forming, rod-shaped facultative an-aerobic gram-negative bacterium found in the intestines of people, the oral cavity of animals, and the environment. Reptiles, guinea pigs, rabbits, jaguars, elephant seals, broiler chickens, piglets, and dolphins have all been documented to have M. morganii infection. Medicinal leeches are used in surgical and non-surgical manners. Treatment of long-term and chronic pain syndrome induced by degenerative diseases in a non-surgical method. For the first time in Iran, our investigation discovered M. morganii-infected Hirudo medicinalis. Infection with M. morganii caused a significant death and morbidity rate (70%) and severe clinical abnormalities.

Abstract

Medicinal leeches (Hirudo medicinalis) are used in surgical and non-surgical manners. Morganella morganii is an opportunistic and zoonotic pathogenic bacterium causing serious clinical complications. In this study, we isolated, discovered and characterized M. morganii-infected H. medicinalis. We detected and identified M. morganii in all inflamed and swollen Hirudo medicinalis samples. The 16S rRNA sequence of the isolates confirmed all strains of M. morganii. All strains were sensitive to Ceftriaxone, Ceftiofur, Danofloxacin, Ciprofloxacin, Enrofloxacin, Oxytetracycline, and Meropenem and were resistant to Erythromycin, Amoxicillin, Ampicillin, Cefazolin, Colistin, Penicillin G, and Lincomycin. This pathogenic bacterium is a zoonotic pathogen, and monitoring the prevalence rate of this bacteria is strongly necessary for leeches used in human medical treatment and care. Finally, all infected leeches were treated successfully in this case report study.

Phthalates released from microplastics inhibit microbial metabolic activity and induce different effects on intestinal luminal and mucosal microbiota

The intestine is not only the main accumulation organ of microplastics (MPs), but also the intestinal environment is very conductive to the release of additives in MPs. However, the kinetics of release process, influence factors, and the related effects on gut microbiota remain largely unknown. In this study, a mucosal-simulator of the human intestinal microbial ecosystem (M-SHIME) was used to investigate the influence of gut microbiota on the release of phthalates (PAEs) from MPs and the effects of MPs on the intestinal luminal microbiota and mucosal microbiota. We found that di-(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DBP), and dimethyl phthalate (DMP) were the dominant PAEs released in the gut. Gut microbiota accelerated the release of PAEs, with the time to reach the maximum release was shortened from 7 days to 2 days. Moreover, MPs induced differential effects on luminal microbiota and mucosal microbiota. Compared with mucosal microbiota, the luminal microbiota was more susceptible to the leaching of PAEs from MPs, as evidenced by more microbiota alterations. MPs also inhibited the metabolic activity of intestinal flora based on the reduced production of short chain fatty acids (SCFA). These effects were mainly contributed by the release of PAEs. Acidaminococcus and Morganella were simultaneously correlated to the release of PAEs and the inhibition of metabolic activity of intestinal microbiota and can be used as indicators for the intestinal exposure of MPs and additives.

Gut symbiotic bacteria are involved in nitrogen recycling in the tephritid fruit fly Bactrocera dorsalis

Background

Nitrogen is considered the most limiting nutrient element for herbivorous insects. To alleviate nitrogen limitation, insects have evolved various symbiotically mediated strategies that enable them to colonize nitrogen-poor habitats or exploit nitrogen-poor diets. In frugivorous tephritid larvae developing in fruit pulp under nitrogen stress, it remains largely unknown how nitrogen is obtained and larval development is completed.

Results

In this study, we used metagenomics and metatranscriptomics sequencing technologies as well as in vitro verification tests to uncover the mechanism underlying the nitrogen exploitation in the larvae of Bactrocera dorsalis. Our results showed that nitrogenous waste recycling (NWR) could be successfully driven by symbiotic bacteria, including Enterobacterales, Lactobacillales, Orbales, Pseudomonadales, Flavobacteriales, and Bacteroidales. In this process, urea hydrolysis in the larval gut was mainly mediated by Morganella morganii and Klebsiella oxytoca. In addition, core bacteria mediated essential amino acid (arginine excluded) biosynthesis by ammonium assimilation and transamination.

Conclusions

Symbiotic bacteria contribute to nitrogen transformation in the larvae of B. dorsalis in fruit pulp. Our findings suggest that the pattern of NWR is more likely to be applied by B. dorsalis, and M. morganii, K. oxytoca, and other urease-positive strains play vital roles in hydrolysing nitrogenous waste and providing metabolizable nitrogen for B. dorsalis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12915-022-01399-9.

Morganella Phage Mecenats66 Utilizes an Evolutionarily Distinct Subtype of Headful Genome Packaging with a Preferred Packaging Initiation Site

Both recognized species from the genus Morganella (M. morganii and M. psychrotolerans) are Gram-negative facultative anaerobic rod-shaped bacteria that have been documented as sometimes being implicated in human disease. Complete genomes of seven Morganella-infecting phages are publicly available today. Here, we report on the genomic characterization of an insect associated Morganella sp. phage, which we named Mecenats66, isolated from dead worker honeybees. Phage Mecenats66 was propagated, purified, and subjected to whole-genome sequencing with subsequent complete genome annotation. After the genome de novo assembly, it was noted that Mecenats66 might employ a headful packaging with a preferred packaging initiation site, although its terminase amino acid sequence did not fall within any of the currently recognized headful packaging subtype employing phage (that had their packaging strategy experimentally verified) with clusters on a terminase sequence phylogenetic tree. The in silico predicted packaging strategy was verified experimentally, validating the packaging initiation site and suggesting that Mecenats66 represents an evolutionarily distinct headful genome packaging with a preferred packaging initiation site strategy subtype. These findings can possibly be attributed to several of the phages already found within the public biological sequence repositories and could aid newly isolated phage packaging strategy predictions in the future.

The adverse effects of high-dose corticosteroid on infectious and non-infectious sequelae in renal transplant recipients with coronavirus disease-19 in India

INTRODUCTION

The corticosteroid dosing modulation in renal transplant recipients (RTRs) with coronavirus disease-19 (COVID-19) is not well defined. We aimed to analyze the outcomes and infectious and non-infectious sequelae in RTR with COVID-19 with reference to corticosteroid dosing and the first and second pandemic waves of COVID-19.

MATERIALS AND METHODS

This study included RTRs admitted during two pandemic waves between March 25, 2020, and July 31, 2021. Patients were categorized into mild, moderate, and severe COVID-19. The outcomes and predictors of survival at 4 weeks were analyzed. The survivors were also followed for 6 months and were studied for mortality, readmission rates, and infectious and non-infectious sequelae with reference to high-dose and standard-dose corticosteroids.

RESULTS

A total of 251 RTRs, 104 during the first wave and 147 during the second wave, were treated. Overall mortality was 15.1% (11.5% in the first wave vs. 17.5% in the second wave, p = .23). The use of high-dose steroids was also significantly high in non-survivors (85.8% vs. 11.3%, p = .001). On multivariate analysis, the severity of COVID-19, graft dysfunction, and high dose of corticosteroid therapy were associated with increased odds of mortality. Among survivors, 6-month mortality (17.3% vs. 0.5%, p = .001), readmission rate (91.3% vs. 23.7%, p = .001), fungal infection (30.4% vs. 2.2%, p < .001), and post-COVID lung sequelae (21.7% vs. 4.4%, p = .008) were significantly higher in the high-dose corticosteroid group than in the standard-dose group.

CONCLUSION

High-dose corticosteroid dosing in RTRs with COVID-19 was associated with increased infections, particularly fungal infections, and non-infectious sequelae with higher mortality on subsequent follow-up.

Antimicrobial Resistance in Bacteria Isolated from Exotic Pets: The Situation in the Iberian Peninsula

Simple Summary

Antimicrobial resistance in exotic pets has not been widely studied. The close contact of this type of animal with the human population increases the risk of untreatable bacterial infections, which represent a veterinary and human public health challenge. We analyze the database of microbiological diagnoses and the bacterial susceptibility to antimicrobials in exotic pets from the Iberian Peninsula. We found that the most prevalent bacteria in birds and mammals were Staphylococcus spp., while in reptiles, they were the Pseudomonas spp. In addition, Pseudomonas showed the highest levels of resistance among the three animal groups, and on the other hand, the multidrug resistance level was significant in Enterobacterales. Most of the bacteria we found have zoonotic importance. The prevalent bacteria are resistant to antimicrobials that have been described as critical for human use, implying that the threat of antimicrobial resistance extends not only to domestic and companion animals but also to humans due to the potential transmission of resistant genes. Once seen from the lens of the One-Health paradigm, these findings are concerning, as they highlight the risk of spreading antibiotic-resistant genes between different individuals and their environments. In order to prevent antibiotic resistance, we encourage the development of joint work between animal and human health specialists.

Abstract

Literature related to antimicrobial resistant (AMR) bacteria in exotic pets is minimal, being essential to report objective data on this topic, which represents a therapeutic challenge for veterinary medicine and public health. Between 2016 and 2020, laboratory records of 3156 exotic pet specimens’ microbiological diagnoses and antibiotic susceptibility testing (AST) results were examined. The samples were classified into three animal classes: birds (n = 412), mammalia (n = 2399), and reptilian (n = 345). The most prevalent bacteria in birds and mammals were Staphylococcus spp. (15% and 16%), while in reptiles they were Pseudomonas spp. (23%). Pseudomonas was the genus with the highest levels of AMR in all animal groups, followed by Enterococcus spp. By contrast, Gram-positive cocci and Pasteurella spp. were the most sensitive bacteria. Moreover, in reptiles, Stenotrophomonas spp., Morganella spp., and Acinetobacter spp. presented high levels of AMR. Multidrug-resistant (MDR) bacteria were isolates from reptiles (21%), birds (17%), and mammals (15%). The Enterobacterales had the highest MDR levels: S. marcescens (94.4%), C. freundii (50%), M. morganii (47.4%), K. pneumoniae (46.6%), E. cloacae (44%), and E. coli (38.3%). The prevalence of MDR P. aeruginosa strains was 8%, detecting one isolate with an XDR profile. Regarding antimicrobial use, many antibiotics described as critically important for human use had significant AMR prevalence in bacteria isolated from exotic pets. Under the One-Health approach, these results are alarming and of public health concern since potential transmission of AMR bacteria and genes can occur from exotic pets to their owners in both senses. For this reason, the collaboration between veterinarians and public health professionals is crucial.

A one health approach versus Acanthamoeba castellanii, a potential host for Morganella morganii

Acanthamoeba castellanii, known as the “Trojan horse of the microbial world,” is known to host a variety of microorganisms including viruses, yeasts, protists, and bacteria. Acanthamoeba can act as a vector and may aid in the transmission of various bacterial pathogens to potential hosts and are found in a variety of places, thus impacting the health of humans, animals, and the environment. These are interconnected in a system known as “one health.” With the global threat of antibiotic resistance, bacteria may avoid harsh conditions, antibiotics, and disinfectants by sheltering within Acanthamoeba. In this study, Acanthamoeba castellanii interaction with Morganella morganii, a Gram-negative bacterium was studied. Escherichia coli K1 interaction with Acanthamoeba was carried out as a control. Association, invasion, and survival assays were accomplished. Morganella morganii was found to associate, invade, and survive within Acanthamoeba castellanii. Additionally, Escherichia coli K1 was also found to associate, invade, and survive within the Acanthamoeba at a higher number in comparison to Morganella morganii. For the first time, we have shown that Morganella morganii interact, invade, and survive within Acanthamoeba castellanii, suggesting that Acanthamoeba may be a potential vector in the transmission of Morganella morganii to susceptible hosts. Taking a one health approach to tackle and develop disinfectants to target Acanthamoeba is warranted, as the amoebae may be hosting various microbes such as multiple drug-resistant bacteria and even viruses such as the novel coronavirus.

Oral administration of asparagine and 3-indolepropionic acid prolongs survival time of rats with traumatic colon injury

BACKGROUND

Traumatic colon injury (TCI) is a common disease during wartime. Prolongation of posttraumatic survival time is an effective approach to patient outcome improvement. However, there is a lack of basic research in this field. This study aimed to elucidate the mechanisms underlying TCI progression and to develop novel regimens to buy time for TCI patients on the battlefield.

METHODS

A total of 669 Sprague-Dawley rats were used in this study. Surgical colon incision was performed to generate the TCI rat model. The landscape of colon microbiota compositions was depicted using 16S rRNA sequencing and metabolites in the intestinal contents were detected by metabolomics profiling. The signaling transduction in the intestinal epithelium was investigated using antibody microarrays and Western blotting. The enzyme-linked immunosorbent assay was conducted to measure the levels of interleukin-6 and tumor necrosis factor-α in intestines and plasma for the detection of inflammatory responses. Diamine oxidase, D-lactate and endotoxin in plasma and protein expression of zonula occludens 1 and occludin were selected as the indicators of intestinal barrier permeability. To investigate alterations of microbiota symbiosis, the relative abundances of specific bacterial genera were detected using quantitative real-time PCR.

RESULTS

As a type of lethal injury, TCI induced acute disruption of intestinal homeostasis, characterized by inflammatory responses, intestinal barrier hyperpermeability and microbiota dysbiosis (P < 0.05). Significant alterations in bacterial metabolic patterns were detected with decreases in many metabolites. After a series of screenings, we found that oral administration of asparagine (Asn) and 3-indolepropionic acid (IPA) effectively prolonged posttraumatic survival time [Asn plus IPA vs. Vehicle: hazard ratio (HR) = 0.105, 95% CI 0.031-0.356, P = 0.0003] and restored intestinal homeostasis in TCI rats (P < 0.05). Mechanistically, this combinational strategy protected the rats against TCI through synergistic activation of Akt signaling in the intestinal epithelium (P < 0.05).

CONCLUSIONS

Abrupt dysregulation of intestinal homeostasis plays a critical role in the progression toward TCI-induced death. Oral administration of Asn plus IPA may serve as an effective regimen to restore intestinal functions and prolong the posttraumatic survival time.

Signs of Rumpwear in the Common Ringtail Possum, Pseudocheirus peregrinus

We report the physical characteristics of rumpwear in the Australian common ringtail possum, Pseudocheirus peregrinus. Rumpwear presents as varying grades of hair breakage and dermatitis on the lumbosacral region. This condition has been reported in Trichosurus spp. (brushtail possums) previously, but never in P. peregrinus. The etiology remains poorly understood.

Microbiota profiling on itchy scalp with undetermined origin

Scalp pruritus is a common skin problem that remains therapeutic challenge. The relationships between the dysbiosis of microbiota and skin diseases have caught attention recently. However, there are few reports about microbiota on itchy scalp. This study investigated scalp microbial characteristics of subjects with mild scalp pruritus of undetermined origin and preliminarily screened physiological factors and bacteria potentially related to pruritus. The pruritus severity of 17 qualified females was evaluated by Visual Analogue Scale (VAS). Microbiota collection was done at both itchy (n = 20) and non-itchy sites (n = 27) at occiput and crown of the same subject and Illumina sequencing was performed at the V3-V4 hypervariable regions of 16S rRNA. The corresponding sebum content, hydration, pH, trans-epidermal water loss, erythema index and porphyrin numbers were also measured by skin tester. We identified 3044 amplicon sequence variants from 821 genera. The itchy and non-itchy sites had different microbiota structures (p = 0.045, by multivariate analysis of variance), while there were large inter- and intra-individual variations. Both sites had Staphylococcus, Cutibacterium and Lawsonella as predominant genera, which were not significantly related to pruritus. The use of three genera Lactobacillus, Morganella and Pseudomonas, could well distinguish non-itchy from itchy groups, whereas different composition patterns existed inside each group. Our investigation indicated that though the bacterial community structure on itchy scalp was individual specific, there was difference between itchy and non-itchy sites. The study provides new insights into microbiota profiling on itchy scalp, which will help microbiota-targeted therapeutic experiment or products design for scalp pruritus.

Multidrug Resistance Genes Carried by a Novel Transposon Tn7376 and a Genomic Island Named MMGI-4 in a Pathogenic Morganella morganii Isolate

Antimicrobial resistance in Morganella morganii is increasing in recent years, which is mainly introduced via extra genetic and mobile elements. The aim of our study is to analyze the multidrug resistance (MDR) and characterize the mobile genetic elements (MGEs) in M. morganii isolates. Here, we report the characteristic of a pathogenic M. morganii isolate containing multidrug resistance genes that are mainly carried by a novel transposon Tn7376 and a genomic island. Sequence analysis suggested that the Tn7376 could be generated through homologous recombination between two different IS26-bounded translocatable units (TUs), namely, module A (IS26-Hp-IS26-mph(A)-mrx(A)-mphR-IS6100-chrA-sul1-qacEΔ1) and module B (ISCR1-sul1-qacEΔ1-cmlA1-aadA1-aadB-intI1-IS26), and the genomic island named MMGI-4 might derive from a partial structure of different original genomic islands that also carried IS26-mediated TUs. Notably, a 2,518-bp sequence linked to the module A and B contains a 570-bp dfrA24 gene. To the best of our knowledge, this is the first report of the novel Tn7376 possessing a complex class 1 integron that carried an infrequent gene dfrA24 in M. morganii.

IMPORTANCE Mobile genetic elements (MGEs), especially for IS26-bounded translocatable units, may act as a reservoir for a variety of antimicrobial resistance genes in clinically important pathogenic bacteria. We expounded this significant genetic characteristic by investigating a representative M. morganii isolate containing multidrug resistance genes, including the infrequent dfrA24. Our study suggested that these acquired resistance genes were mainly driven by IS26-flanked important MGEs, such as the novel Tn7376 and the MMGI-4. We demonstrated that IS26-related MGEs contributed to the emergence of the extra gene dfrA24 in M. morganii through some potential genetic events like recombination, transposition, and integration. Therefore, it is of importance to investigate persistently the prevalence these MEGs in the clinical pathogens to provide risk assessment of emergence and development of novel resistance genes.

Complete Genome Sequence of Morganella morganii CTX51T, Isolated from a Human Cecal Adenocarcinoma

We report the complete genome sequence of Morganella morganii CTX51T, a strain isolated from the resected tumor of a patient with cecal colorectal adenocarcinoma of the cecum. The genome comprises a circular chromosome of 4.19 Mbp, with an overall GC content of 50.4% and one circular plasmid of 8.48 kbp.