Polymicrobial Acute Suppurative Parotitis in a 33-Day-Old Infant: A Case Report and Review of the Literature.

BACKGROUND: Acute suppurative parotitis (ASP) of neonates is a rare condition characterized by irritability, erythema, and tenderness of the affected gland. METHODS/RESULTS: Only few cases have been reported in Engilsh literature, mostly in male neonates, in a unilateral fashion. In our case, a polymicrobial etiology (Klebsiella pneumoniae, Staphylococcus aureus, Acinetobacter ursingii, and Acinetobacter junii) was found. Based on the review of the microbiological findings of cases of ASP in English literature for the years 1970 to 2020, S. aureus is the most commonly isolated microorganism (47% of the total 65 patients). Our patient was born with a C-section procedure and was not breast-fed, making dysbiosis along with the usage of the feeding bottle, possible risk factors for the development of ASP. CONCLUSIONS: ASP may be due to polymicrobial etiology. Initial presentation in neonates may not include typical signs and symptoms, like fever. Aseptic technique of oral procedures is of utmost importance also in immune-competent neonates.

Pediatric deep neck infections: Clinical description and analysis of therapeutic management.

OBJECTIVES: The aim of our study was to describe clinical presentations, bacteriological results, and therapeutic management in a pediatric population presenting with acute pharyngeal suppuration. A further aim was to identify clinical, bacteriological, and radiological predictors of success associated with exclusive medical treatment. METHOD: A retrospective study was carried out including patients under 18 years of age hospitalized between January 1, 2015 and December 31, 2017 in our center for acute pharyngeal suppuration. We identified three groups of patients: group A, treated with exclusive intravenous antibiotics; group B, surgically treated after 48 h of appropriate antibiotic therapy, due to persistent fever and/or clinical worsening and/or persistence of a collection on follow-up imaging; group C, surgically treated as first-line therapy in association with intravenous antibiotics. A total of 83 patients were included: 36 in group A, 12 in group B, and 35 in group C. These three groups were compared for several variables: age of the patients, polynuclear neutrophil counts, diameter of the collections (the largest diameter found on imaging), duration of antibiotic therapy, delay before return to apyrexia, and hospitalization duration. RESULTS: A neck mass and torticollis were present, respectively, in 48.8 and 47.6% of cases. No breathing difficulties were reported. Streptococcus pyogenes was the most frequently identified microorganism. The average diameter of the collections from patients treated surgically as first-line therapy (group C) was significantly larger than that of the patients treated with antibiotics (group A) (27.89 mm vs. 18.73 mm, respectively, p = 0.0006). All the patients who required surgery despite 48 h of appropriate antibiotic therapy (group B) had collections with diameters greater than or equal to 15 mm. There was no significant difference between the groups concerning hospitalization duration. CONCLUSION: Exclusive medical treatment is associated with a high cure rate, mainly for collections with small diameter. We recommend special attention to patients treated with first-line exclusive intravenous antibiotic therapy and with a collection diameter greater than or equal to 15 mm.

Prevalence of Panton Valentine Leucocidin gene containing Staphylococcus aureus in pus samples from Paediatric patients.

Staphylococcus (Staph) aureus containing Panton Valentine Leucocidin (PVL) gene are spreading in the whole world. This gene encodes PVL toxin that has lytic effect on WBCs contributing to the low immunity of the body. It also causes pus formation in various places of the body. This study was conducted to understand the effect of PVL positive Staph aureus in causing purulent infections in children between the age of one day to 15 years. Pus samples from various sites of the body from children between the age of one day to 15 years were taken. The number of pus samples containing Staph aureus was 45. These were collected over a period of one year, from October 2, 2017 to September 30, 2018, at the Shaikh Zayed Hospital, Lahore. A total of 27 (60%) PVL samples were positive Staph aureus. Prevalence of PVL gene was noted to be high in MSSA 9(64%), wound swabs 18(75%), in isolates from orthopaedic department 6(75%), indoor 21(63%), and in males 18(66%). Our study showed that most of the Staph aureus samples that were obtained from pus samples from children had PVL gene in their genome. This percentage is very high. To control its spread, we need to treat not only the patients but also their close contacts. The main objective to conduct this study was to assess the prevalence of PVL positive Staph aureus strain in our local setup. Paediatric age group was selected because it is the most vulnerable group and pus samples were chosen because this strain causes recurrent purulent infections.

Multidrug resistance pattern of Acinetobacter species isolated from clinical specimens referred to the Ethiopian Public Health Institute: 2014 to 2018 trend anaylsis.

BACKGROUND: Acinetobacter species have been a leading cause of nosocomial infections, causing significant morbidity and mortality over the entire world including Ethiopia. The most important features of A. baumannii are its ability to persist in the hospital environment and rapidly develop resistance to a wide variety of antibiotics. This study aimed to determine trend of antimicrobial resistance in Acinetobacter species over a five years period. METHOD: A retrospective data regarding occurrence and antimicrobial resistance of Acinetobacter species recovered from clinical specimens referred to the national reference laboratory was extracted from microbiology laboratory data source covering a time range from 2014 to 2018. Socio-demographic characteristics and laboratory record data was analyzed using SPSS 20. RESULTS: A total of 102 strains of Acinetobacter species were analyzed from various clinical specimens. Majority of them were from pus (33.3%) followed by blood (23.5%), urine (15.6%) and body fluid (11.7%). Significant ascending trends of antimicrobial resistance was shown for meropenem (12.5% to 60.7%), ceftazidime (82.1% to 100%), ciprofloxacin (59.4% to 74.4%), ceftriaxone (87.1% to 98.6%), cefepime (80.0% to 93.3%) and pipracillin- tazobactam (67.8% to 96.3%). However, there was descending trend of antimicrobial resistance for tobramycin (56.5% to 42.8%), amikacin (42.1% to 31.4%) and trimethoprim-sulfamethoxazole (79.0 to 68.2%). The overall rate of carbapenem non-susceptible and multidrug resistance rates in Acinetobacter species were 56.7% and 71.6%.respectively. CONCLUSION: A five year antimicrobial resistance trend analysis of Acinetobacter species showed increasing MDR and resistance to high potent antimicrobial agents posing therapeutic challenge in our Hospitals and health care settings. Continuous surveillance and appropriate infection prevention and control strategies need to be strengthened to circumvent the spread of multidrug resistant pathogens in health care facilities.

Real-time PCR versus MALDI-TOF MS and culture-based techniques for diagnosis of bloodstream and pyogenic infections in humans and animals.

AIMS: This study was applied to evaluate the usefulness of a high-throughput sample preparation protocol prior to the application of quantitative real-time PCR (qPCR) for the early diagnosis of bloodstream and pyogenic infections in humans and animals compared to matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and classical culture. METHODS AND RESULTS: Saponin-mediated selective host cell lysis combined with DNase-1 was applied for processing of whole blood and pus clinical samples collected from suspected cases of septicaemia and pyogenic infections in humans and animals. The pre-PCR processing strategy enabled the recovery of microbial cells with no changes in their colony forming units immediately after the addition of saponin. DNase-1 was efficient for removing the DNAs from the host cells as well as dead cells with damaged cell membranes. The metagenomic qPCR and MALDI-TOF MS could identify the bacterial community of sepsis at species level with a concordance of 97·37% unlike the conventional culture. According to qPCR results, Staphylococcus aureus (24·24%) was predominated in animal pyogenic infections, whereas Klebsiella pneumonia (31·81%) was commonly detected in neonatal sepsis. CONCLUSIONS: Saponin combined with DNase-1 allowed the efficient recovery of microbial DNA from blood and pus samples in sepsis using qPCR assay. SIGNIFICANCE AND IMPACT OF THE STUDY: Metagenomic qPCR could identify a broad range of bacteria directly from blood and pus with more sensitivity, higher discriminatory power and shorter turnaround time than those using MALDI-TOF MS and conventional culture. This might allow a timely administration of a prompt treatment.

Antimicrobial therapy and assessing therapeutic response in culture-negative pyogenic vertebral osteomyelitis: a retrospective comparative study with culture-positive pyogenic vertebral osteomyelitis.

BACKGROUND: There are still controversies regarding the treatment and outcomes in culture-negative pyogenic vertebral osteomyelitis (PVO). The purpose of this study is to investigate the antimicrobial therapy, assessment of therapeutic response, and outcome of culture-negative PVO compared to culture-positive PVO. METHODS: A retrospective study was performed with non-surgical lumbar PVO patients. The patients were divided into two groups based on the causative bacterial identification (CN group with culture-negative PVO and CP group with culture-positive PVO). The clinical features, use of antibiotics, laboratory data, and outcomes were compared between the two groups. RESULTS: Seventy-three patients with 41 (56.2%) of the CN group and 32 (43.8%) of the CP group were enrolled. The CN group showed a shorter duration of parenteral antibiotics (45.88 ± 16.14 vs. 57.31 ± 24.39, p = 0.019) but a tendency of prolonged duration of total (parenteral + oral) antibiotics (101.17 ± 52.84 vs. 84.19 ± 50.29 days, p = 0.168). When parenteral antibiotics were discontinued or switched to oral antibiotics, the mean erythrocyte segmentation rate (ESR, normal range: < 25 mm/h), C-reactive protein (CRP, normal range: < 0.5 mg/dL) level, and visual analog scale (VAS) score of back pain were 42.86 ± 24.05 mm/h, 0.91 ± 1.18 mg/dL, and 4.05 ± 1.07, respectively, with no significant differences between the two groups. The recurrence rates of CN and CP groups were 7.3% (3/41) and 6.3% (2/32), respectively (p = 1.000). The presence of epidural abscess was the most significant factor for the identification of causative bacteria (p = 0.002), and there was no significant relationship between the use of empirical antibiotics before tissue culture and the causative bacterial identification (p = 0.194). CONCLUSIONS: The CN group required a shorter duration of parenteral antibiotics than the CP group. Discontinuation of parenteral antibiotics or changing the administration route can be considered based on the values of ESR, CRP, and VAS score of back pain. The presence of epidural abscess was the most significant factor for the identification of causative bacteria.

Is there a change in trend towards pyogenous spondylodiscitis compared to tubercular spondylodiscitis in India-A study of percutaneous biopsy evaluation in spondylodiscitis.

BACKGROUND: In Indian subcontinent where tuberculosis is endemic, the spinal infection was thought to be due to mycobacterium tuberculosis in most of the cases. Hence there is a practice of treating these patients with empirical antitubercular treatment. However, recent guidelines advice biopsy and tissue diagnosis before starting antibiotics. OBJECTIVE OF STUDY: Our retrospective study analyses the role of biopsy in establishing the microbiological diagnosis and thus identifying the incidence of pyogenic and tubercular spondylodiscitis presented to a tertiary care centre. MATERIALS AND METHODS: All patients who were diagnosed as spondylodiscitis by clinical and radiological criteria and who underwent biopsy were included in the study and data was retrieved from medical records and PACS. Criteria for tubercular spondylodiscitis included presence of mycobacterium tuberculosis either in smear/gene Xpert, or histopathological evidence of tuberculosis. Organism isolation other than MTB or absence of tubercular granuloma and response to antibiotics were considered as non-tubercular aetiology. RESULTS: Our study achieved 84% (n-63) accuracy for first biopsy and 34 patients (53.96%) were diagnosed as pyogenic spondylodiscitis. Organisms were isolated in 11 cases (32%) of pyogenic spondylodiscitis and tubercular bacilli in 17 cases (65%) of tubercular spondylodiscitis. Aspiration of pus yielded better isolation of organisms (P < 0.001) in pyogenic spondylodiscitis. 11% of cases showed drug resistant tuberculosis. CONCLUSION: We conclude that there is an increasing trend of pyogenous spondylodiscitis compared to tubercular spondylodiscitis in patients presenting to tertiary care centre, hence biopsy is essential to start antimicrobials.

Streptococcus anginosus purulent pericarditis with cardiac tamponade after coronary artery bypass surgery.

Purulent pericarditis caused by Streptococcus anginosus is extremely rare. A 66-year-old man underwent elective coronary artery bypass surgery. This was complicated by sternal wound dehiscence with drainage. Subsequently, he developed fever, progressive dyspnoea and presyncope. Echocardiography showed a large pericardial effusion with evidence of tamponade. He underwent emergent pericardiocentesis. The pericardial fluid culture grew S. anginosus He was treated with 4 weeks of intravenous ceftriaxone with complete clinical recovery. The source of infection was most likely the sternal wound which was overlooked during debridement and rewiring surgery.

Prevalence of nontuberculous mycobacteria in a tertiary hospital in Beijing, China, January 2013 to December 2018.

BACKGROUND: To investigate the species distribution of non-tuberculous mycobacteria (NTM) among tuberculosis (TB) specimens collected from January 2013 to December 2018 at Peking Union Medical Hospital (Beijing), China. NTM species identification was carried out by DNA microarray chip. RESULTS: Mycobacterial species were detected in 1514 specimens from 1508 patients, among which NTM accounted for 37.3% (565/1514), increasing from a proportion of 15.6% in 2013 to 46.1% in 2018 (P < 0.001). Among the 565 NTM positive specimens, the majority (55.2%) were from female patients. Furthermore, patients aged 45-65 years accounted for 49.6% of the total patients tested. Among 223 NTM positive specimens characterized further, the majority (86.2%) were from respiratory tract, whilst 3.6 and 3.1% were from lymph nodes and pus, respectively. Mycobacterium intracellulare (31.8%) and Mycobacterium chelonae / Mycobacterium abscessus (21.5%) were the most frequently detected species, followed by M. avium (13.5%), M. gordonae (11.7%), M. kansasii (7.6%), and others. CONCLUSION: The proportion of NTM among mycobacterial species detected in a tertiary hospital in Beijing, China, increased rapidly from year 2013 to 2018. Middle-aged patients are more likely to be infected with NTM, especially females. Mycobacterium intracellulare and Mycobacterium chelonae/ Mycobacterium abscessus were the most frequently detected NTM pathogens. Accurate and timely identification of NTM is important for diagnosis and treatment.

The prevalence and molecular mechanisms of mupirocin resistance in Staphylococcus aureus isolates from a Hospital in Cape Town, South Africa.

BACKGROUND: Antimicrobial resistance is an increasingly serious problem in public health globally. Monitoring resistance levels within healthcare and community settings is critical to combat its ongoing increase. This study aimed to describe the rates and molecular mechanisms of mupirocin resistance in clinical Staphylococcus aureus isolates from Tygerberg Hospital, and to describe its association with strain types. METHODS: We retrospectively selected 212 S. aureus isolates which were identified from blood samples and pus swabs during the years 2009-2011 and 2015-2017. The isolates were identified using conventional microbiological methods and genotyping was done using spa typing. Cefoxitin (30 µg) disc diffusion and the two disc strategy (5 µg and 200 µg) were used to determine susceptibility to methicillin and mupirocin, respectively. Isolates with high-level resistance were screened for the plasmid mediated genes mupA and mupB by PCR, and sequencing of the ileS gene was done for all isolates exhibiting low-level resistance to describe the mutations associated with this phenotype. Chi-square test was used to assess the associations between mupirocin resistance and S. aureus genotypes. RESULTS: Of 212 S. aureus isolates, 12% (n = 25) were resistant to mupirocin, and 44% (n = 93) were methicillin resistant. Strain typing identified 73 spa types with spa t045 being the most predominant constituting 11% of the isolates. High-level mupirocin resistance was observed in 2% (n = 5), and low-level resistance in 9% (n = 20) of the isolates. The prevalence of high-level mupirocin resistance amongst MRSA and MSSA was 4 and 1% respectively, while the prevalence of low-level mupirocin resistance was significantly higher in MRSA (18%) compared to MSSA (3%), (p = 0.032). mupA was the only resistance determinant for high-level resistance, and the IleS mutation V588F was identified in 95% of the isolates which showed low-level resistance. A significant association was observed between spa type t032 and high-level mupirocin resistance, and types t037 and t012 and low-level resistance (p <  0.0001). CONCLUSION: The study reported higher rates of low-level mupirocin resistance compared to high-level resistance, and in our setting, mupirocin resistance was driven by certain genotypes. Our study advocates for the continuous screening for mupirocin resistance in S. aureus in clinical settings to better guide treatment and prescribing practices.

An insight into analysis and elimination of plasmids encoding metallo-ß-lactamases in Pseudomonas aeruginosa.

OBJECTIVES: The aim of this study was to characterise metallo-ß-lactamase (MBL)-harbouring plasmids, their change in copy number in respect to different antibiotic pressure, and the efficiency of different curing agents in eliminating these resistance plasmids from nosocomial Pseudomonas aeruginosa isolates. METHODS: Plasmids were extracted from four isolates harbouring blaNDM-1 or blaVIM-2 under four different concentrations of imipenem, meropenem, ertapenem, aztreonam and cefotaxime. Quantitative real-time PCR was performed to analyse the change in plasmid copy number under these different conditions. The effect of different physical and chemical curing agents in elimination of plasmids carrying blaNDM-1 and blaVIM-2 was examined, with meropenem resistance used as a selectable marker. RESULTS: Conjugatively transferable MBL genes (blaNDM-1 and blaVIM-2) carried on plasmids were found to be highly stable. Sodium dodecyl sulfate (SDS) was the most effective agent in eliminating these resistance plasmids. The change in copy number of the blaNDM-1-encoding plasmid was found to be similar to the blaVIM-2-encoding plasmid, with a single exception under cefotaxime pressure. CONCLUSION: The spread of multidrug resistance plasmids has been noted as a key factor associated with increasing carbapenem resistance. Successful curing of resistance plasmids can reverse the bacterial phenotype back to susceptible. This study revealed that different antibiotic pressure induces a change in copy number of MBL-encoding plasmids. SDS can be successfully used as an eliminating agent for these resistance determinants, although therapeutic application of this agent is not possible due to its high toxicity and mutagenic nature.

Uselessness of microbiological samples in acute appendicitis with frank pus: to collect or not to collect?

INTRODUCTION: Current use of antimicrobial therapy is prophylactic, empirical and broad spectrum. But, the age-old practice of obtaining cultures still remain. The aim of this study was to evaluate bacterial etiology and adequacy of antibiotic prophylaxis in patients diagnosed with acute appendicitis to help determine the utility of intraoperative cultures in guiding clinical decision-making. MATERIALS AND METHODS: A retrospective analysis of a prospectively constructed database of all patients who underwent appendectomy from September 2013 to November 2016 was performed. RESULTS: 456 patients underwent surgery for acute appendicitis in our academic hospital. 101 patients (22.1%) had intraoperative swabs taken, and the cultures were positive in 57.4% of patients. These 101 patients comprise our study group. The most commonly recovered species were E. coli, Streptococcus spp., Bacteroides fragilis, Enterococcus faecium, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Proteus. In the comparison between positive and negative swab, there were no differences in terms of surgical site infection, deep infection, and in terms of Clavien-Dindo classification. An appropriate empiric therapy was set in 88.5% and inappropriate in 11.5%. No differences in terms of surgical site infection or in length of stay (p = 0.657) were found, with a median of 7 days in both groups. CONCLUSION: The etiological agents causing peritonitis due to acute appendicitis are predictable and empiric-targeted antibiotic therapy is effective in a high percentage of patients. The postoperative patient outcome may be dependent on the severity of the appendicitis more than on the results of the swab at the time of surgery. In this study, intraoperative culture was not associated with the choice of antibiotics, incidence of SSI, DPI or the length of stay.

Performance of Xpert MTB/RIF for detection of Mycobacterium tuberculosis and rifampicin resistance in pus aspirates.

INTRODUCTION: WHO endorsed Xpert MTB/RIF assay has proven to be rapid with results obtained within 2h. The evidence base regarding the use of Xpert MTB/RIF in pulmonary TB is strong. Relatively few performance data have been published to date on detection of Mycobacterium tuberculosis in aspirated pus specimens from abscesses. OBJECTIVES: The aim of the study was to determine the sensitivity and specificity of Xpert MTB/RIF assay for the detection of M. tuberculosis and rifampicin resistance in aspirated pus specimens using culture on Lowenstein Jensen (LJ) medium and economic variant of proportion method (PM) for drug susceptibility testing (DST) as the reference standard. RESULTS: Xpert MTB/RIF assay in comparison to conventional reference method showed sensitivity and specificity of 76.19% and 68.75% for detection of M. tuberculosis and 71.4% and 100% for detection of rifampicin resistance respectively. CONCLUSION: The simplicity, sensitivity, speed and automation makes this assay a very promising diagnostic test for detection of M. tuberculosis and rifampicin resistance in aspirated pus specimens.

Case for diagnosis. Suppurative nodule or something deeper?

The authors report the case of a 62-year-old man with a history of total left hip arthroplasty nine years previously presenting with a large infiltrated plaque on the posterior area of the left thigh with three months of evolution without systemic symptoms or elevated inflammatory markers. Computed tomography of the left lower limb revealed a 12-centimeter linear extension of the lesion to the posterior part of the left proximal femur. Prosthesis joint infection, although rare, is a surgical complication to be taken into account, even if the surgery was performed many years before.

Synergistic effect of silver nanoparticles and polymyxin B against biofilm produced by Pseudomonas aeruginosa isolates of pus samples in vitro.

Pseudomonas aeruginosa (P. aeruginosa) is an aerobic gram-negative, non-spore forming, rod-shaped bacterium. It accelerates the decline in lung function and ultimately leads to increased mortality and morbidity rate. Survival and virulence of P. aeruginosa is due to its biofilm formation ability. The main aim of this study was to test the synergistic effect of silver nanoparticles (AgNPs) in combination with Polymyxin B against biofilms of P. aeruginosa. A total of 500 pus aspirations were collected and bacterial pathogens were identified. Biofilm formation was attained using a glass tube method and microtiter plate assay. The minimum inhibitory concentration of Polymyxin B was determined using agar well diffusion method. Silver nanoparticles were synthesized by chemical reduction method followed by determination of their anti-pseudomonal ability separately and in combination with Polymyxin B using microtiter plate assay. Our results showed that 120 out of 500 samples were Pseudomonas positive. The ratio of multidrug-resistant (MDR) in our collected Pseudomonas samples was 83% (25/30). Generally, the minimum inhibitory concentration (MIC) of Polymyxin B was 16 µg/mL and that of AgNPs was null. However, AgNPs showed great synergistic effect in combination with Polymyxin B. Synergistically, the efficacy of Polymyxin B was enhanced four times as compared to unaided Polymyxin B.

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.

Is Gonococcal Paraurethral Duct Infection a Local Complication of Urethral Gonorrhea in Men?

Gonococcal paraurethral duct infection in males has previously been regarded as a local complication of urethral gonorrhea. To verify this, pathogens were investigated in urethral secretions from 81 male patients with gonococcal paraurethral duct infection. In patients with gonococcal infections of both the urethra and the paraurethral duct, the times of onset of the first symptoms associated with urethral gonorrheal and gonococcal paraurethral duct infection were compared. Among 81 male patients with gonococcal paraurethral duct infection, gonococci were detected in the urethras of 76 patients and no pathogens were detected in the urethras of the remaining 5 patients. The first symptom associated with urethral gonorrhea and gonococcal paraurethral duct infection occurred simultaneously in 10 cases. In 7 cases, the first symptom of gonococcal paraurethral duct infection occurred 2-4 days (2.29 ± 0.76 days) earlier than that of urethral gonorrhea and in 59 cases, the first symptom of urethral gonorrhea occurred 1-6 days (3.07 ± 1.19 days) earlier than that of gonococcal paraurethral duct infection. This study shows that gonococcal paraurethral duct infection in males can be caused by primary infection of Neisseria gonorrhoeae.

Case for diagnosis. Suppurative nodule or something deeper?

Abstract: The authors report the case of a 62-year-old man with a history of total left hip arthroplasty nine years previously presenting with a large infiltrated plaque on the posterior area of the left thigh with three months of evolution without systemic symptoms or elevated inflammatory markers. Computed tomography of the left lower limb revealed a 12-centimeter linear extension of the lesion to the posterior part of the left proximal femur. Prosthesis joint infection, although rare, is a surgical complication to be taken into account, even if the surgery was performed many years before.

Population divergence of Pseudomonas aeruginosa can lead to the coexistence with Escherichia coli in animal suppurative lesions.

Purulent disease is the main factor that prevents the population increase of forest musk deer in artificial breeding, and especially the intracorporal suppurative lesions in late-stage with complex bacterial communities normally bring more difficulties for veterinary treatment. Although it is well-recognized that Pseudomonas aeruginosa and Escherichia coli are the two main bacterial pathogens which can be frequently co-isolated from the lung pus of forest musk deer, few studies have explored the interspecific relationship and coexistent mechanism of the two species. In this study, we identified a P. aeruginosa strain MYL-2, which harbored a loss-of-function mutation in the central regulator (LasR) of quorum-sensing (QS) system, from the lung pus of a dying forest musk deer with co-infecting E. coli strain MYL-58. Interestingly, P. aeruginosa MYL-2 could coexist with E. coli MYL-58 compared to the dominant role of lasR-intact P. aeruginosa strain MYL-1 in the competitive experiments. The results of in vitro coevolution assay further revealed that the QS-mediated competitive advantage of P. aeruginosa MYL-1 would be decreased along with the enrichment of lasR mutants in the communities, and P. aeruginosa could finally coexist with E. coli by forming a relatively stable equilibrium. Therefore, these findings provide an evolutionary explanation for the coexistence of P. aeruginosa and E. coli in the suppurative lesions of forest musk deer, and may also contribute to further understanding the pathology of animal purulent disease and the development of novel veterinary therapy.