Serratia Chorioamnionitis and Culture Proven Sepsis in a Preterm Neonate: A Case Report and Review of the Literature.

BACKGROUND: Serratia marcescens is a well-known cause of nosocomial infectious outbreaks in the neonatal intensive care unit, with a high mortality rate in the vulnerable preterm population. However, it is not typically associated with neonatal sepsis secondary to intrapartum vertical transmission. We present the case of a preterm male born at 25 weeks and 4 days of gestation in Okinawa, Japan with culture-proven S. marcescens chorioamnionitis and sepsis, as well as a review of the previously published literature. METHODS: We conducted a literature search utilizing MeSH indexing with the headings [chorioamnionitis], [Serratia], and [infant, newborn] limited to "humans" with a publication date range between 1950 and 2020. RESULTS: All reported cases of preterm S. marcescens chorioamnionitis occurred in coastal locations. The majority of cases resulted in spontaneous abortion, and we found no published reports of confirmed S. marcescens chorioamnionitis in conjunction with viable preterm delivery and positive neonatal cultures. In the case presented herein, S. marcescens chorioamnionitis with associated neonatal sepsis was confirmed by positive placental and blood cultures. Bacterial clearance was achieved following an antibiotic course consisting of 5 days of gentamicin and 14 days of meropenem therapy. CONCLUSIONS: S. marcescens is an uncommon cause of chorioamnionitis that can have devastating neonatal consequences, especially in the at-risk preterm population.

The Serratia marcescens Siderophore Serratiochelin Is Necessary for Full Virulence during Bloodstream Infection.

Serratia marcescens is a bacterium frequently found in the environment, but over the last several decades it has evolved into a concerning clinical pathogen, causing fatal bacteremia. To establish such infections, pathogens require specific nutrients; one very limited but essential nutrient is iron. We sought to characterize the iron acquisition systems in S. marcescens isolate UMH9, which was recovered from a clinical bloodstream infection. Using RNA sequencing (RNA-seq), we identified two predicted siderophore gene clusters (cbs and sch) that were regulated by iron. Mutants were constructed to delete each iron acquisition locus individually and in conjunction, generating both single and double mutants for the putative siderophore systems. Mutants lacking the sch gene cluster lost their iron-chelating ability as quantified by the chrome azurol S (CAS) assay, whereas the cbs mutant retained wild-type activity. Mass spectrometry-based analysis identified the chelating siderophore to be serratiochelin, a siderophore previously identified in Serratia plymuthica Serratiochelin-producing mutants also displayed a decreased growth rate under iron-limited conditions created by dipyridyl added to LB medium. Additionally, mutants lacking serratiochelin were significantly outcompeted during cochallenge with wild-type UMH9 in the kidneys and spleen after inoculation via the tail vein in a bacteremia mouse model. This result was further confirmed by an independent challenge, suggesting that serratiochelin is required for full S. marcescens pathogenesis in the bloodstream. Nine other clinical isolates have at least 90% protein identity to the UMH9 serratiochelin system; therefore, our results are broadly applicable to emerging clinical isolates of S. marcescens causing bacteremia.

Protective effect of neglected plant Diplocyclos palmatus on quorum sensing mediated infection of Serratia marcescens and UV-A induced photoaging in model Caenorhabditis elegans.

Plants are considered to be a leading source for possible human therapeutic agents. This holistic study has investigated the anti-quorum sensing (anti-QS), anti-infection, antioxidant and anti-photoaging properties of neglected plant Diplocyclos palmatus. The results showed that D. palmatus methanolic leaf extract (DPME) effectively inhibited the quorum sensing (QS) regulated virulence factor production as well as biofilm formation in Serratia marcescens. The transcriptomic analysis revealed that DPME significantly downed the expression of QS-regulated genes such as fimA, fimC, flhC, bsmB, pigP and shlA in S. marcescens, which supports the outcome of in vitro bioassays. Further, the docking study revealed that the presence of active compounds, namely tocopherols and phytol, DPME exhibited its anti-QS activity against S. marcescens. In addition, DPME treatment extended the lifespan of S. marcescens infected C. elegans by the action of dropping the internal accumulation. Further, qPCR analysis clearly revealed that DPME treatment significantly up-regulated the expression of the lifespan-related gene (daf-16) and immune-related genes (clec-60, clec-87, lys-7 and bec-1) in S. marcescens infected C.elegans. On the other hand, DPME extensively reduced the UV-A induced ROS stress, thereby, extended the lifespan in UV-A photoaged C. elegans. Further, the qPCR analysis also confirmed the up-regulation of daf-16, clec-60, clec-87 and col-19 genes which advocated the improvement of the lifespan, healthspan and collagen production in UV-A photoaged C. elegans. Further bioassays evidenced that that the lifespan extension of photoaged C. elegans was accomplished by the actions of antioxidants such as tocopherols and phytol in DPME.

Blowing epithelial cell bubbles with GumB: ShlA-family pore-forming toxins induce blebbing and rapid cellular death in corneal epithelial cells.

Medical devices, such as contact lenses, bring bacteria in direct contact with human cells. Consequences of these host-pathogen interactions include the alteration of mammalian cell surface architecture and induction of cellular death that renders tissues more susceptible to infection. Gram-negative bacteria known to induce cellular blebbing by mammalian cells, Pseudomonas and Vibrio species, do so through a type III secretion system-dependent mechanism. This study demonstrates that a subset of bacteria from the Enterobacteriaceae bacterial family induce cellular death and membrane blebs in a variety of cell types via a type V secretion-system dependent mechanism. Here, we report that ShlA-family cytolysins from Proteus mirabilis and Serratia marcescens were required to induce membrane blebbling and cell death. Blebbing and cellular death were blocked by an antioxidant and RIP-1 and MLKL inhibitors, implicating necroptosis in the observed phenotypes. Additional genetic studies determined that an IgaA family stress-response protein, GumB, was necessary to induce blebs. Data supported a model where GumB and shlBA are in a regulatory circuit through the Rcs stress response phosphorelay system required for bleb formation and pathogenesis in an invertebrate model of infection and proliferation in a phagocytic cell line. This study introduces GumB as a regulator of S. marcescens host-pathogen interactions and demonstrates a common type V secretion system-dependent mechanism by which bacteria elicit surface morphological changes on mammalian cells. This type V secretion-system mechanism likely contributes bacterial damage to the corneal epithelial layer, and enables access to deeper parts of the tissue that are more susceptible to infection.

Supposed endogenous endophthalmitis caused by Serratia marcescens in a cat.

An 8-year-old male neutered domestic shorthair cat was presented for evaluation of acute respiratory distress. Respiratory auscultation revealed a diffuse and symmetric increase in bronchovesicular sounds. Thoracic radiographs showed a diffuse unstructured interstitial pulmonary pattern with multifocal alveolar foci. Despite an aggressive treatment with supportive care, including oxygenotherapy and systemic antibiotics, progressive respiratory distress increased. Three days after the presentation, acute anterior uveitis was noticed on left eye. Ophthalmic examination and ocular ultrasonography revealed unilateral panuveitis with ocular hypertension. The right eye examination was unremarkable. Cytological examination of aqueous humor revealed a suppurative inflammation. Serratia marcescens was identified from aqueous humor culture. Primary pulmonary infection was suspected but was not confirmed as owners declined bronchoalveolar lavage. Active uveitis resolved and cat's pulmonary status improved after appropriate systemic antibacterial therapy. Vision loss was permanent due to secondary mature cataract. To the best of authors' knowledge, this is the first report of endogenous bacterial endophthalmitis secondary to S. marcescens infection in a cat.

Infección por Serratia marcescens: una inusual causa de lesiones cutáneas / Serratia marcescens infection: an unusual cause of skin lesions

Serratia marcescens corresponde a un bacilo gram negativo, miembro de la familia Enterobacteriaceae. Este microorganismo tiene una alta capacidad de supervivencia en condiciones hostiles y ha sido implicado en infecciones del tracto respiratorio, vía urinaria, meningitis, endocarditis y sistema musculoesquelético. No obstante, es considerado una causa rara de infecciones cutáneas. Esta última tiene distintas presentaciones clínicas, la más frecuente es fascitis necrotizante seguida de celulitis. Los nódulos, las pápulas después de inyecciones de rellenos, las erupciones papulares diseminadas, las placas eritematosas, las pústulas y las úlceras son parte del amplio espectro de formas clínicas descritas en la literatura. Presentamos el caso de una paciente de 50 años, con historia de compromiso del estado general, lesiones cutáneas polimorfas y fiebre. Se confirmó una infección cutánea por Serratia marcescens mediante cultivos. Se destaca el polimorfismo y la coexistencia de distintas manifestaciones en una misma paciente, incluyendo celulitis, nódulo, ulceras y necrosis cutánea y la importancia del estudio microbiológico para el adecuado tratamiento antibiótico.

Serratia marcescens corresponds to gram negative bacillus, a member of the Enterobacteriaceae family. This microorganism has a high survival capacity in hostile conditions and has been implicated in respiratory tract, urinary tract, meningitis, endocarditis and musculoskeletal system infections. However, it is considered a infrequent cause of cutaneous infections. Has different clinical presentations, the most frequent is necrotizing fasciitis followed by cellulite. Nodules, papules after filler injections, disseminated papular eruption, erythematous plaques, pustules and ulcers are part of the broad spectrum of clinical forms described in the literature. We present the case of a 50 year old patient with a history of compromised general condition, polymorphic cutaneous lesions and fever. Serratia marcescens cutaneous infection was confirmed by cultures. The polymorphism and the coexistence of different manifestations in the same patient, including cellulitis, nodule, ulcers and skin necrosis, and the importance of the microbiological study for the adequate antibiotic treatment are highlighted.

Sepsis after uterine artery embolization-assisted termination of pregnancy with complete placenta previa: A case report.

Uterine artery embolization (UAE)-assisted induction of labor is an alternative method of managing pregnant women with complete placenta previa (CPP). Sepsis secondary to UAE, although rare, is a serious complication. We herein present a case of severe sepsis following UAE-assisted termination of a pregnancy at 27 gestational weeks in a woman with CPP. The woman developed a high-grade fever and elevated inflammatory indices following UAE. She did not recover until the infected tissue was removed by emergency cesarean section. This case suggests that the increasing use of UAE for termination of pregnancy in women with CPP requires awareness regarding the possibility of serious sepsis associated with this procedure.

A rare case of community acquired serratia lung abscess in a patient with cardiac bronchus.

The incidence of lung abscess caused by Serratia marcescens is extremely low and is only reported in the immunocompromised population. We present a previously healthy woman with Serratia lung abscess in close proximity with an accessory cardiac bronchus. The patient was treated with appropriate antibiotics which led to complete resolution of the lesion. Our case highlights that individuals without medical co-morbidities may develop atypical lung infections like Serratia when associated with anatomic anomalies.

Serratia marcescens Bullous Cellulitis in a Splenectomized Patient: A Case Report and Review of the Literature.

Serratia marcescens is a Gram-negative bacillus belonging to the Enterobacteriaceae family. Cutaneous infection with Serratia is rare, and usually occurs in immunocompromised individuals. Primary cutaneous infections are uncommon, but they are typically severe and are associated with significant morbidity and mortality. The pathogenetic factors leading to S. marcescens infection are not fully understood, but contributing virulence factors include proteases, secreted exotoxins, and the formation of biofilm. We report a case of cellulitis occurring in a splenectomized patient, which led to multiple wound debridements and a transmetatarsal amputation. This dramatic case led us to review the published literature on soft tissue infections caused by S. marcescens.

Necrotizing cellulitis with multiple abscesses on the leg caused by Serratia marcescens.

Serratia marcescens is an unusual cause of severe skin infection initially described in immunocompromised patients. We report a case of necrotizing cellulitis of the leg caused by S marcescens in a 68-year-old woman with diabetes mellitus and a history of chronic lymphoedema of the leg. We reviewed the literature and found 49 cases of severe skin infections from S marcescens that included 20 cases of necrotizing fasciitis (NF) as well as 29 cases of severe skin infections without NF (non-NF cases). Patients were immunocompromised in 59% to 70% of cases. The mortality rate was high in NF cases (60%) versus non-NF cases (3%). Surgery was required in 95% of NF cases and in 24% of non-NF cases. The other clinical manifestations of S marcescens skin infection reported in the literature included disseminated papular eruptions in patients infected with human immunodeficiency virus with folliculitis on the trunk. Serratia marcescens is naturally resistant to amoxicillin alone and amoxicillin associated with clavulanic acid. Broad-spectrum antibiotics are indicated to treat S marcescens skin infections, and surgery should be promptly considered in cases of severe skin infections if appropriate antibiotic therapy does not lead to rapid improvement.

Pathogenicity of pan-drug-resistant Serratia marcescens harbouring blaNDM-1.

OBJECTIVES: To characterize a pan-drug-resistant Serratia marcescens clinical isolate carrying the New Delhi metallo-ß-lactamase (NDM)-1. METHODS: The presence of ß-lactamase genes was examined by PCR and sequencing. Antibiotic susceptibility was determined by antibiotic gradient test. Transformation assays, transconjugation assays, PFGE and PCR-based replicon typing were used for plasmid analysis. Horizontal gene transfer was evaluated by liquid mating using Escherichia coli J53 as a recipient. Pathogenicity of NDM-1 expressing S. marcescens was analysed using the Galleria mellonella infection model. RESULTS: S. marcescens isolate SM1890 was non-susceptible to all tested antibiotics, with minocycline retaining intermediate activity. blaNDM-1 was located on a 140 kb IncA/C-type plasmid which was transferable to E. coli and Klebsiella pneumoniae by conjugation. The LD50 of the NDM-positive, SM1890 isolate was higher than that of other, NDM-1 negative, S. marcescens strains. CONCLUSIONS: The presence of a blaNDM-1-harbouring IncA/C plasmid resulted in marked resistance to ß-lactam antibiotics, but had no significant effect on virulence of isogenic strains. Because of the intrinsic resistance of S. marcescens to colistin and reduced susceptibility to tigecycline, treatment options for infections by NDM-1-positive isolates are extremely limited in this species.

Interactions between the tropical sea anemone Aiptasia pallida and Serratia marcescens, an opportunistic pathogen of corals.

Coral reefs are under increasing stress caused by global and local environmental changes, which are thought to increase the susceptibility of corals to opportunistic pathogens. In the absence of an easily culturable model animal, the understanding of the mechanisms of disease progression in corals remains fairly limited. In the present study, we tested the susceptibility of the tropical sea anemone Aiptasia pallida to an opportunistic coral pathogen (Serratia marcescens). A. pallida was susceptible to S. marcescens PDL100 and responded to this opportunistic coral pathogen with darkening of the tissues and retraction of tentacles, followed by complete disintegration of polyp tissues. Histological observations revealed loss of zooxanthellae and structural changes in eosinophilic granular cells in response to pathogen infection. A screen of S. marcescens mutants identified a motility and tetrathionate reductase mutants as defective in virulence in the A. pallida infection model. In co-infections with the wild-type strain, the tetrathionate reductase mutant was less fit within the surface mucopolysaccharide layer of the host coral Acropora palmata.

Serratia marcescens: an unusual pathogen associated with snakebite cellulitis.

This study reports a case of Serratia marcescens cellulitis following a snakebite in a 50-year-old woman. The bite was on the dorsum of the right hand with symptoms of envenomation. She developed swelling and cellulitis with tissue necrosis. Wound debridement was performed.  Pus and tissue biopsy cultures yielded Serratia marcescens sensitive to fluoroquinolones, aminoglycosides, third-generation cephalosporins and carbapenems. The patient responded to anti-snake venom (ASV) therapy, ciprofloxacin, local wound management and recovered uneventfully.