Periprosthetic joint infection remains one of the most serious complications after total hip arthroplasty ^[1]. Although contemporary diagnostic frameworks, including International Consensus Meeting criteria and Infectious Diseases Society of America guidance, have improved evaluation and treatment, clinical decision-making remains difficult when infection is chronic, resistant, polymicrobial, or recurrent ^[2,3]. Staphylococci remain the predominant organisms in total hip arthroplasty infection, but Gram-negative bacilli account for a clinically important subset and may be associated with antimicrobial resistance patterns that limit standard therapy ^[4]. Pseudomonas aeruginosa is difficult to eradicate and has variable outcomes across debridement, antibiotics, implant retention, and component-exchange strategies ^[5,6]. Serratia marcescens is much less common, with most available literature limited to isolated cases or small reviews ^[7,8]. Fungal periprosthetic joint infection is also uncommon. Candida species represent a small subset, and Candida glabrata is particularly challenging because of reduced azole susceptibility. Current guidance generally supports prosthesis removal, staged revision when appropriate, and prolonged antifungal therapy ^[9,10]. Methicillin-resistant Staphylococcus aureus is another difficult pathogen in arthroplasty infection and is associated with increased risk of treatment failure ^[11,12,13]. We report a rare case of sequential, culture-confirmed infections with P. aeruginosa, C. glabrata, methicillin-resistant S. aureus, and S. marcescens after a single total hip arthroplasty.

A 62-year-old woman with hypertension, chronic anaemia, and a prior methicillin-resistant S. aureus infection underwent robotic-assisted left total hip arthroplasty without immediate complications. Ethnic background was not available in the deidentified record. She did not have diabetes mellitus, and her serology status was negative. Two months postoperatively, she developed worsening hip pain, swelling, and localised warmth. Blood cultures and joint aspiration grew P. aeruginosa. Through the original incision, all components were removed, extensive debridement was performed, multiple deep tissue samples were obtained before antibiotic administration, and an antibiotic-loaded cement spacer was placed. She received 3 weeks of intravenous (IV) antipseudomonal beta-lactam therapy followed by 12 weeks of oral ciprofloxacin based on susceptibility testing. The P. aeruginosa isolate was susceptible to all tested agents on the provided panel, including cefepime, ceftazidime, ciprofloxacin, meropenem, piperacillin-tazobactam, and aminoglycosides (Table 1).

Table 1: Culture and susceptibility results by infection episode. This table summarizes the available culture reports, Gram stain findings, antimicrobial susceptibility interpretations, and visible minimum inhibitory concentration values. For Candida glabrata, the available report confirmed growth but did not include an antifungal susceptibility panel.

After an approximately 2-week antibiotic-free interval, repeat aspiration was performed. At 4 months, persistent concern for infection led to spacer exchange rather than reimplantation. Approximately 3 months later, she again developed hip pain and swelling. Aspiration and intraoperative cultures grew C. glabrata. Repeat debridement and spacer exchange were performed after cultures were obtained. She completed 6 weeks of echinocandin therapy followed by high-dose fluconazole. Reimplantation was again deferred because of ongoing concern for infection. The available C. glabrata report confirmed rare growth, but it did not include an antifungal susceptibility panel (Table 1). Because no formal antifungal susceptibility panel was included in the available C. glabrata report, antifungal treatment was selected under infectious disease guidance, using echinocandin therapy followed by high-dose fluconazole step-down; complete antifungal minimum inhibitory concentration (MIC) data were not available in the deidentified record. One month later, recurrent symptoms prompted repeat evaluation, and cultures yielded methicillin-resistant S. aureus. She underwent repeat debridement with spacer exchange, with multiple deep cultures obtained before antibiotics. She completed 6 weeks of IV vancomycin using area-under-the-curve-guided dosing. Rifampin was considered after wound stabilisation. The interstage plan again included protected weight-bearing, multidisciplinary follow-up, an antibiotic-free interval, and repeat aspiration. The methicillin-resistant S. aureus susceptibility report showed resistance to oxacillin, erythromycin, cefazolin, amoxicillin-clavulanate, and ampicillin-sulbactam, intermediate susceptibility to ciprofloxacin, and susceptibility to vancomycin, daptomycin, linezolid, rifampin, trimethoprim-sulfamethoxazole, clindamycin, gentamicin, levofloxacin, moxifloxacin, quinupristin-dalfopristin, and tetracycline (Table 1). Approximately 4 months later, she experienced a fourth recurrence, and cultures grew S. marcescens. Management again included debridement through the existing incision, spacer exchange, and culture-directed antimicrobial therapy. She received 6 weeks of IV cefepime, followed by an antimicrobial-free interval and repeat aspiration. The S. marcescens isolate was reported as a multidrug-resistant organism and a carbapenem-resistant Enterobacterales. It was resistant to multiple agents, including ertapenem and meropenem, but remained susceptible to cefepime, ceftazidime, ceftazidime-avibactam, ciprofloxacin, piperacillin-tazobactam, aminoglycosides, levofloxacin, and trimethoprim-sulfamethoxazole (Table 1). After approximately 4 months of negative cultures, a well-healed wound, and normalised inflammatory markers, definitive reimplantation was performed. At 9 months after reimplantation, there was no evidence of recurrent infection, and the patient was regaining function with physical therapy. The susceptibility results are summarised in Table 1, and the sequential management decisions are summarised in Table 2 and Fig. 1.

Table 2: Sequential infection episodes after left total hip arthroplasty. This table summarizes the timing, culture-confirmed organism, diagnostic method, treatment, and outcome during staged management. Definitive reimplantation was performed once cultures remained negative, the wound had healed, inflammatory markers had normalized, and aspiration after an antibiotic-free interval was reassuring. No patient-specific clinical or intraoperative photographs were available; operative records described use of a temporary antibiotic-loaded cement hip spacer.

Figure 1: Timeline of sequential infections. Clinical timeline of four culture-confirmed periprosthetic joint infections after left total hip arthroplasty. Dots mark culture confirmation, shaded bars show organism-directed therapy, and the star marks final reimplantation. Reimplantation was deferred at the 4-month review because of persistent concern for infection.

A PubMed-focused literature review was performed using combinations of the following keywords: total hip arthroplasty, periprosthetic joint infection, staged revision, P. aeruginosa, C. glabrata, methicillin-resistant S. aureus, S. marcescens, spacer exchange, and reimplantation. The available literature describes these pathogens individually in prosthetic joint infection, but the sequential emergence of four distinct pathogens in the same hip arthroplasty is rarely represented. This makes the case educational because each recurrence required a fresh diagnostic and therapeutic approach rather than simply extending the prior treatment plan. Given the complexity of this case, the available culture and susceptibility information is summarised in Table 1. The bacterial reports allow reporting of sensitive, resistant, and intermediate interpretations with MIC dilutions where visible in the available reports. The only remaining missing susceptibility detail is the antifungal susceptibility panel for C. glabrata, which was not included in the provided report. The Gram-negative episodes contributed substantially to management complexity. In chronic P. aeruginosa prosthetic joint infection, revision with component exchange has been associated with higher success than debridement, antibiotics, and implant retention in many settings, and prolonged targeted therapy remains important ^[5,6,14]. Oral fluoroquinolone therapy is generally most appropriate when susceptibility is confirmed. S. marcescens prosthetic joint infection is uncommon, but reported cases emphasise the importance of adequate debridement and organism-directed antimicrobial therapy ^[7,8]. The identification of C. glabrata required a major change in strategy. Because this organism may have reduced azole susceptibility, guidelines favour prosthesis removal and prolonged antifungal therapy, often beginning with an echinocandin and transitioning to fluconazole only when susceptibility and clinical response support that approach ^[9,10,15]. In this patient, repeat deep cultures were prioritised before treatment changes, and reimplantation was deferred until clinical, serologic, and microbiologic parameters were reassuring. When methicillin-resistant S. aureus was isolated, vancomycin was administered with area-under-the-curve-guided dosing to balance efficacy and nephrotoxicity risk ^[16]. Rifampin was considered because of its activity against staphylococcal biofilm, but its role must be individualised, particularly because available evidence is mixed and may depend on the surgical strategy used ^[12,13,17]. The central lesson from this case is that recurrent infection during staged arthroplasty management should not be assumed to represent persistence of the original organism. Repeat cultures changed management at each episode. Similarly, reimplantation was not performed according to a fixed timeline; it was delayed until the wound was quiet, inflammatory markers had normalised, and aspiration after an antimicrobial-free interval was negative. This approach is consistent with guidance emphasising clinical judgement and microbiologic confirmation before reimplantation ^[3,18,19]. This case report is limited by its single-patient design and short-term follow-up after final reimplantation. The sequential emergence of distinct organisms may reflect host factors, prior antimicrobial exposure, healthcare-related exposure, or other variables that cannot be fully separated in a case report. Nonetheless, the case provides a practical example of culture-driven decision-making in a rare and complex periprosthetic hip infection. Additional limitations include the absence of patient-specific clinical or intraoperative photographs and the lack of an antifungal susceptibility panel for the C. glabrata isolate in the provided report. The bacterial susceptibility reports were available and are summarised in Table 1, but interpretation remains limited by the single-patient design and the retrospective nature of the case report.

Sequential periprosthetic hip infections can disrupt standard staged-revision pathways when new pathogens emerge between procedures. This case highlights the importance of repeated culture acquisition, organism-directed antimicrobial therapy, thorough debridement with spacer exchange when indicated, and individualised reimplantation timing. For orthopaedic surgeons and infection specialists, the case reinforces that each recurrence should be treated as a new diagnostic event until culture data prove otherwise.

In recurrent or staged hip periprosthetic joint infection, a new positive culture should not be assumed to represent persistence of the original organism. Re-culturing, targeted therapy, and individualised reimplantation timing are essential when sequential pathogens emerge.