Spontaneous extrusion of renal calculi presenting as a retroperitoneal abscess

Spontaneous extrusion of a kidney stone is an extremely rare event with few reported cases. We present the unusual case of a 62-year-old female who presented with worsening of fever and flank pain over a 5 day period. Imaging revealed retroperitoneal and abdominal wall abscesses that upon evaluation of prior imaging were attributed to spontaneously extruded kidney stones. Prior reports suggest surgical exploration and extraction is the preferred treatment option for extruded renal calculi. Based on the experience presented here, conservative management may be an attractive first-line treatment option for patients with extruded renal stones and associated retroperitoneal abscesses.

Complications of chronic suppurative otitis media: a left otogenic brain abscess and a right mastoid fistula

Otogenic brain abscess and postauricular fistula are complications of chronic suppurative otitis media. We describe a rare case of bilateral chronic suppurative otitis media that caused a left temporal lobe abscess and a right mastoid fistula.

Psoas abscess ten years after ipsilateral nephrectomy for pyonephrosis

Pyogenic abscess of the psoas muscle is a rare disease. The Authors report a recently observed case which developed 10 years after ipsilateral nephrectomy for pyonephrosis, reviewing the pertinent literature. The culture of the pus extracted only reproduced Proteus mirabilis. The relation between psoas abscess and nephrectomy is unclear. To make diagnosis is important to consider this condition in differential diagnosis in presence of fever and flank tenderness in a nephrectomized patient.

Spontaneous bacterial peritonitis causing Serratia marcescens and Proteus mirabilis ventriculoperitoneal shunt infection. Case report

The authors report their experience treating a polymicrobial ventriculoperitoneal (VP) shunt infection in a developmentally delayed 21-year-old woman. Cerebrospinal fluid (CSF) cultures grew Serratia marcescens and Proteus mirabilis. On admission and throughout her hospitalization, results of physical examination of her abdomen were normal, and radiographic studies showed no evidence of bowel perforation or pseudocyst formation. Contrast-enhanced computed tomography of the abdomen revealed a small fluid collection. After a course of intravenous gentamicin and imipenem with cilastatin in conjunction with intrathecal gentamicin, the infection was resolved and the VP shunt was reimplanted. Although VP shunt infections are not uncommon, S. marcescens as a causative agent is exceedingly rare and potentially devastating. Only two previous cases of S. marcescens shunt infection have been reported in the literature. Authors reporting on S. marcescens infections in the central nervous system (CNS) have observed significant morbidity and death. Although more common, the presence of P. mirabilis in the CSF is still rare and highly suggestive of bowel perforation, which was absent in this patient. Spontaneous bacterial peritonitis was the likely source from which these bacteria gained entrance into the VP shunt system, eventually causing ventriculitis in this patient. The authors conclude that in light of the high morbidity associated with S. marcescens infection of the CNS, intrathecal administration of gentamicin should be strongly considered as part of first-line therapy for S. marcescens infections in VP shunts.

Intracranial complications following mastoidectomy

Mastoidectomy is a common surgical procedure in otology. However, postoperative complications of various degrees of severity may occur. We present 4 children who underwent mastoidectomy for middle ear and mastoid disease and developed postoperative intracranial complications. One child was operated on for brain abscess 1 week after the initial mastoidectomy. Another child appeared with seizures 5 days after the initial mastoidectomy and a subdural empyema was drained during revision surgery. Large bone defects with exposed middle cranial fossa dura were found at revision surgery in both cases and Proteus vulgaris and methicillin-resistant Staphylococcus aureus were isolated from the mastoid and abscess cavities in these children. A small epidural collection was diagnosed in the third patient 2 days after initial mastoid surgery and was managed with intravenous antibiotics only. The other child was found to have sigmoid sinus thrombosis the day after mastoidectomy that was performed for nonresponsive acute mastoiditis. This child received both intravenous antibiotics and anticoagulants. Timely revision surgery, combinations of third- or fourth-generation cephalosporins with vancomycin or metronidazole and the addition of anticoagulants in cases of sinus thrombosis can lead to full recovery.

Lesson of the week: perils of pessaries

Vaginal pessaries are widely considered to be a safe alternative to surgery in older women. We report a case of near fatal septicaemia in a 75-year-old woman associated with a shelf pessary, the presence of which was identified during an exploratory laparotomy. This case highlights the importance of the gynaecological history and examination when assessing older women with septicaemia of unknown source.

Proteus mirabilis genes that contribute to pathogenesis of urinary tract infection: identification of 25 signature-tagged mutants attenuated at least 100-fold

Proteus mirabilis, a common cause of urinary tract infections (UTI) in individuals with functional or structural abnormalities or with long-term catheterization, forms bladder and kidney stones as a consequence of urease-mediated urea hydrolysis. Known virulence factors, besides urease, are hemolysin, fimbriae, metalloproteases, and flagella. In this study we utilized the CBA mouse model of ascending UTI to evaluate the colonization of mutants of P. mirabilis HI4320 that were generated by signature-tagged mutagenesis. By performing primary screening of 2088 P. mirabilis transposon mutants, we identified 502 mutants that ranged from slightly attenuated to unrecoverable. Secondary screening of these mutants revealed that 114 transposon mutants were reproducibly attenuated. Cochallenge of 84 of these single mutants with the parent strain in the mouse model resulted in identification of 37 consistently out-competed P. mirabilis transposon mutants, 25 of which were out-competed >100-fold for colonization of the bladder and/or kidneys by the parent strain. We determined the sequence flanking the site of transposon insertion in 29 attenuated mutants and identified genes affecting motility, iron acquisition, transcriptional regulation, phosphate transport, urease activity, cell surface structure, and key metabolic pathways as requirements for P. mirabilis infection of the urinary tract. Two mutations localized to a approximately 42-kb plasmid present in the parent strain, suggesting that the plasmid is important for colonization. Isolation of disrupted genes encoding proteins with homologies to known bacterial virulence factors, especially the urease accessory protein UreF and the disulfide formation protein DsbA, showed that the CBA mouse model and mutant pools are a reliable source of attenuated mutants with mutations in virulence genes.

Psoas abscess twenty-one years after ipsilateral nephrectomy

We report an unusual case of psoas abscess, which developed twenty-one years after ipsilateral nephrectomy and was caused by infrequent pathogen, Proteus mirabilis. It was diagnosed by computed tomography and was drained percutaneously with a nephrostomy tube guided by ultrasonography.

Staghorn calculus in renal allograft presenting as acute renal failure

BACKGROUND

Urolithiasis is a rare complication in renal transplant recipients. We report a case of a staghorn calculus occurring in renal allograft, presenting as anuric renal failure with Gram-negative sepsis.

METHODS AND RESULTS

A 48-year-old Caucasian female, with end-stage renal disease due to autosomal dominant polycystic kidney disease, underwent cadaveric renal transplantation in 1986. Sixteen years after transplant, she presented with Gram-negative sepsis with Proteus mirabilis and acute anuric renal failure in the allograft. After undergoing an emergency nephrostomy and treatment of sepsis, a staghorn calculus was subsequently removed by percutaneous nephrolithotomy. Based on the stone analysis and history of urinary tract infections with urease splitting bacteria, the calculus was thought to be infection-induced.

CONCLUSION

Although a rare complication, urolithiasis in an allograft can be associated with significant morbidity. Immediate recognition is critical to restore renal allograft function and to treat associated serious infection in an immunocompromised patient.

Polymer surface properties and their effect on the adhesion of Proteus mirabilis

A problem encountered in patients undergoing long-term catheterization of the urinary tract is that of encrustation and blockage of the catheter by crystalline bacterial biofilms. This is principally caused by the action of the urease-producing pathogen Proteus mirabilis. A major aim of this work is to develop materials resistant to encrustation. Here, the effects of polymer surface properties on the adhesion of P. mirabilis are examined. Spin-coated polymer films were characterized through contact angle measurements to give the Lifschitz-van der Waals, electron acceptor and electron donor terms of the surface free energy, gamma(s)LW, gamma(s)+ and gamma(s)- respectively. A parallel-plate flow cell was used to assess adhesion to these polymer films of P. mirabilis suspended in an aqueous phosphate buffer, pH 7.4, ionic strength 0.26 mol/kg. P. mirabilis was found to adhere significantly less (p < 0.02) to films of agarose, poly(2-hydroxyethylmethacrylate) and cross-linked poly(vinyl alcohol) than to more hydrophobic materials. These polymer films were found to be strongly electron donating, i.e. possessing large gamma(s)-. Films examined using scanning electron microscopy mostly showed no evidence of roughness down to a scale of 1-10 microm. The better performance is thought to be due to a repulsive interaction with the bacterial surface caused by acid/base-type interactions.

Venous sinus thrombosis after Proteus vulgaris meningitis and concomitant Clostridium abscess formation

A 19-y-old woman presented with Proteus vulgaris meningitis as a complication of chronic otitis media. Despite treatment with ceftazidime and amikacin no clinical improvement was observed. Cranial MRI revealed right-sided mastoiditis/otitis media and venous sinus thrombosis. After mastoidectomy, repeat cranial MRI demonstrated abscess formation in the venous sinuses. The abscess was drained. Clostridium spp. was isolated from the abscess culture.

[Psoas abscess. Etiology and treatment]

Psoas abscess is in general a syndrome with low incidence. In the following, two cases are presented which describe the etiology, diagnosis, and treatment of primary and secondary retroperitoneal manifestations. The article mainly focuses on the different respective surgical procedures. Because of its rareness, an overview of further cases discussed in the literature is provided.

Protean infectious types and frequent association with neurosurgical procedures in adult Serratia marcescens CNS infections: report of two cases and review of the literature

Serratia marcescens is a rare pathogen of adult central nervous system (CNS) infection. We report on the clinical features and therapeutic outcomes of two adult patients with such infections. The clinical characteristics of 13 other reported adult cases are also included for analysis. The 15 cases were nine males and six females, aged 19-83 years, in whom, underlying post-neurosurgical states and ear operation were noted in 93% (14/15). Fever and conscious disturbance were the most common clinical manifestations of these 15 cases, followed by hydrocephalus, seizures, and wound infections. The manifestation types were protean, including meningitis and focal suppurations such as brain abscess, cranial and spinal epidural abscess, cranial subdural abscess, and infected lumbar pseudomeningocele. One case of S. marcescens CNS infection was diagnosed postmortem; the other 14 were diagnosed by the positive culture from CSF or pus. Antibiotic therapy with or without neurosurgical intervention was the management strategy in 14/15 cases. The therapeutic results showed a high mortality rate.

Using VAC to treat a vascular bypass site infection

Vacuum-assisted closure is becoming an increasingly popular adjunctive therapy. The following evidence suggests it can be used to treat an infected groin incision over a patent vascular bypass.

Pattern of gram negative rods bacteraemia in diabetic patients in Ibadan, Nigeria

In a study of 100 patients in Ibadan between July and December 1995 to evaluate bacteraemia due to gram-negative bacilli, 64% were culture positive, 44 (68.8%) of these yielded gram-negative rods. The isolates were Klebsiella species (43.2%), Escherichia coli (27.3%), Pseudomonas aeruginosa (13.6%), Proteus species (11.4%) and Bacteroides melaninogenious (4.15%) by standard bacteriological methods. Antimicrobial sensitivity results suggested ofloxacin or ceftriaxone with metronidazole as empirical antibiotic therapy.

Bacteriology of diabetic foot

OBJECTIVES

To study the relative frequency of bacterial isolates cultured from diabetic foot infections and assess their comparative in vitro susceptibility to the commonly used antibacterial agents.

METHODS

This is a retrospective study with a review of the bacteriology results of specimens taken from 111 consecutive patients with diabetic foot infections at King Abdulaziz University Hospital, Jeddah, Kingdom of Saudi Arabia, during the period January 1997 to June 1999. The specimens were cultured using optimal aerobic and anaerobic microbiologic techniques. Antimicrobial susceptibility testing to different agents, was carried out using the disc diffusion method.

RESULTS

Staphylococcus aureus was the commonest isolate being recovered from 28% of cases, including methicillin resistant staphylococcus aureus in 9 of 30 (30%) patient wounds. The other organisms isolated were Pseudomonas aeruginosa (22%) and Proteus mirabilis (18%), anaerobic gram-negative organisms (11%) mainly Bacteroides fragilis. The antimicrobial susceptibility testing, showed that vancomycin was the most effective against gram-positive and and imipenem was the most effective against gram-negative organisms.

CONCLUSION

Staphylococcus aureus, Pseudomonas aeruginosa, Proteus mirabilis and Bacteroides fragilis were the most common causes of diabetic foot infections. These wounds require use of combined antimicrobial therapy for initial patient management prior to susceptibility results.

Iron status of Libyan infants with urinary tract infection

Serum iron, serum total iron binding capacity and tranferrin saturation levels were measured in 45 infants, of whom 19 had urinary tract infections confirmed by positive suprapubic aspiration. The control group comprised 26 healthy infants with negative results. Mean serum iron and transferrin saturation values were significantly lower in infants with urinary tract infection compared with the control group (P < 0.01 and P < 0.001 respectively), especially if the cultured organism was Escherichia coli (P < 0.01, P < 0.02). Total iron binding capacity was within the normal range. We conclude that iron deficiency is not a major factor in the etiopathogenesis of urinary tract infection in Libyan infants.

Ability of Proteus mirabilis to swarm over urethral catheters

The aim of this study was to investigate the ability of Proteus mirabilis to swarm over various types of urinary catheters. The test strain was found to swarm over catheters for distances of up to 10 cm within 24 h. Migration was significantly more rapid over hydrogel-coated latex catheters than over all-silicone or silicone-coated latex catheters. Scanning electron micrographs revealed discrete rafts of typically elongated swarmer cells on catheter surfaces. Migration of swarmers along catheters into the bladder could thus initiate Proteus mirabilis catheter-associated infections.

Psoas abscess following extracorporeal shock wave lithotripsy

Different studies have reported renal effects like swelling of parenchyma, subcapsular and intracapsular haematoma and perinephric fluid collections. These effects were usually transient and by 2-3 months returned to normal. We report an early complication of extracorporeal shock wave lithotripsy (ESWL). A patient with solitary renal calculus who had ESWL developed psoas spasm and became unwell with elevation of white cell count and erythrocyte sedimentation rate. Psoas abscess extending from renal hilum to the groin was diagnosed and drained surgically.

Thermal necrosis after tibial reaming for intramedullary nail fixation. A report of three cases

We present three young men who sustained closed diaphyseal fracture of the tibia and later developed severe osteocutaneous necrosis induced by heat during intramedullary reaming. They all had a narrow medullary cavity and in all a tourniquet had been used. Each developed a pretibial cutaneous blister soon after operation. In the following month severe osteomyelitis ensued, requiring segmental resection and osteocutaneous reconstruction.

Endophthalmitis in patients with retained lens fragments after phacoemulsification

PURPOSE

To review the treatment and outcomes of patients presenting with concurrent endophthalmitis and retained lens fragments after phacoemulsification.

METHODS

A retrospective chart review was conducted on patients presenting with culture-proven endophthalmitis and retained lens fragments after phacoemulsification between 1990 and 1994.

RESULTS

Five patients were identified with culture-proven endophthalmitis and retained lens fragments after phacoemulsification. In all patients, coagulase-negative staphylococci were cultured from the vitreous fluid. One patient also had positive cultures for Proteus mirabilis and Escherichia coli. The interval between cataract surgery and treatment ranged from 5 days to 6 months. Echography was beneficial in showing retained lens fragments in five of five patients when media opacities obscured the view of the fundus. Four patients had vitrectomy and removal of retained lens fragments during their initial treatment. The fifth patient was treated with intravitreal antibiotics alone and continued to have marked inflammation, eventually requiring vitrectomy for removal of the retained lens fragments. A final visual acuity of 20/400 or better was achieved in four of the five patients.

CONCLUSIONS

Patients may present with endophthalmitis in the setting of retained lens fragments after phacoemulsification. In such cases, the preferred initial management may be pars plana vitrectomy, removal of retained lens fragments, and injection of intraocular antibiotics. In eyes with endophthalmitis and opaque media, echography is a useful screening modality.

[Retroperitoneal abscess following extracorporeal shock-wave lithotripsy]

An additional case of perinephric abscess post-ESWL is described. The clinical and radiological features and the therapeutic approach are discussed. The literature is briefly reviewed.

Proteus mirabilis fimbriae: construction of an isogenic pmfA mutant and analysis of virulence in a CBA mouse model of ascending urinary tract infection

Proteus mirabilis, a cause of urinary tract infection and acute pyelonephritis, produces a number of different fimbriae. An isogenic fimbrial mutant of P. mirabilis HI4320 was constructed by marker exchange with delta pmfA::aphA to determine the role of the P. mirabilis fimbriae (PMF) in hemagglutination and in virulence in the CBA mouse model of ascending urinary tract infection. The pmfA mutant, which did not express the 19,500-Da major subunit of PMF, colonized the bladders of transurethrally challenged CBA mice (n = 20 in each group) in numbers 83-fold lower than those of the wild-type strain (mutant, log10 4.87 CFU/g; wild-type strain, log10 6.79 CFU/g; P = 0.023). However, the mutant colonized the kidneys in numbers similar to those of the wild-type strain. Hemagglutination patterns of the mutant ruled out the involvement of PMF in both mannose-resistant, Proteus-like and mannose-resistant, Klebsiella-like hemagglutination. Similarly, PMF does not appear to be involved in adherence to uroepithelial cells (UEC), since the mutant was as adherent as the wild-type strain (mutant, 14.1 +/- 11.7 mean bacteria per UEC, 60% of UEC with > or = 10 bacteria; wild-type strain, 18.1 +/- 16.2 mean bacteria per UEC, 68% of UEC with > or = 10 bacteria; not significantly different). These data suggest a role for PMF in colonization of the bladder but not in colonization of kidney tissue. PMF appear not to be responsible for mannose-resistant, Proteus-like or mannose-resistant, Klebsiella-like hemagglutination.

Postoperative endophthalmitis resulting from prosthesis contamination in a monocular patient

Monocular patients who wear an ocular prosthesis may harbor pathogenic conjunctival flora both in the socket and in the contralateral eye. They may therefore be at increased risk of developing endophthalmitis after intraocular procedures. We studied a monocular, prosthesis-wearing, 86-year-old man who underwent cataract extraction, subtotal transpupillary vitrectomy, and intraocular lens insertion. Fulminant endophthalmitis ensued postoperatively, and despite complete vitrectomy and administration of intraocular antibiotics, the eye lost light perception. Intravitreal as well as conjunctival cultures bilaterally grew Proteus mirabilis. The patient disclosed that he cleaned the prosthesis frequently because of discharge. We considered an association between this bacterial colonization and the risk of developing postoperative endophthalmitis and suggest prophylactic measures for treatment of monocular patients undergoing intraocular procedures.

[The pathogenetic aspects of the hyaluronidase activity of Proteus mirabilis]

The hyaluronidase activity of 83 P. mirabilis strains has been studied. The strains isolated from patients with chronic urologic infection possess the highest hyaluronidase activity, while the activity of strains isolated in cases of enteric disturbances and from purulent wound exudate has proved to be considerably lower, the difference between the latter being statistically insignificant. The hyaluronidase activity of P. mirabilis may be increased when the culture is grown in the presence of blood serum, and in strains isolated from internal organs an increase in hyaluronidase activity and the production of slime-like substance by bacterial cells can be observed. After the parenteral infection of animals with paired strains differing in their hyaluronidase activity differences in the course of infection were noted.

Late presentation of infection as a complication of Dwyer anterior spinal instrumentation

Delayed presentation of infection is a rare complication of anterior instrumentation and fusion for scoliosis. Three cases that followed the Dwyer procedure are reported. Pain was absent in these patients, but mild constitutional symptoms were present. An elevated erythrocyte sedimentation rate (ESR) is an important indicator of this complication. Two patients developed groin abscesses and sinuses as the hallmark of deep infection. Infection resolved after removal of instrumentation and local debridement.

Risk of bacteraemia during extracorporeal shock wave lithotripsy

Extracorporeal shock wave lithotripsy (ESWL) is widely used to treat urinary calculi. With increasing numbers of ESWL, more patients prone to infectious complications will be treated. However, little is known about the infectious risks of ESWL. To provide a basis for the rational use of antimicrobial prophylaxis, we studied the incidence of bacteraemia during ESWL. A total of 23 patients with urinary calculi were treated. Blood cultures (4-7 per patient) were taken before, during and immediately after ESWL, adding up to a total of 154 cultures. In 22 of these patients no bacteraemia was detected. In 1 patient small numbers of 2 different micro-organisms were found in 2 blood samples only. This finding, and the circumstances of blood collection, suggested contamination rather than bacteraemia. It was concluded that the risk of bacteraemia during ESWL is very low.

The effect of repeated instillations of antiseptics on catheter-associated urinary tract infections: a study in a physical model of the catheterized bladder

The activity of three antiseptic bladder washout solutions was examined in a physical model of the catheterized bladder. Tests were performed against cultures of four common urinary tract pathogens that had established themselves in the model and colonized the surfaces with biofilm. Double instillations of chlorhexidine (0.02% w/v) at 6-h intervals failed to eliminate Pseudomonas aeruginosa, Proteus mirabilis, and Providencia stuartii from the bladder model. Escherichia coli, however, was susceptible to a second instillation provided that it was performed within 12 h. Supplementing chlorhexidine with EDTA and TRIS potentiated its activity against E. coli. Mandelic acid (1.0% w/v) was the most effective of the agents, double instillations eliminating all but Pr. mirabilis infections.

[Xerophthalmia in liver cirrhosis. Correct diagnosis after 15 years]

The clinical features of xerophthalmia are described in a 60-year-old patient, who was known to have alcoholic cirrhosis. In this patient, vitamin A deficiency, which presumably had been overlooked for 15 years, was confirmed by determination of the serum vitamin A level. After substitutive vitamin A therapy, superficial punctate keratitis and conjunctival xerosis disappeared completely. Although xerophthalmia has only sporadically been described in developed countries, we point out that the possibility of a vitamin A deficiency should also be considered in cases of recurrent conjunctival and corneal lesions.

Bacterial colonization behaviour: a new virulence strategy in urinary infections?

The urinary bladder resists bacterial colonization and infection by a number of mechanisms, one of which involves the sloughing of colonized uroepithelial cells. Pathogens which thus become detached from bladder tissue are rapidly eliminated upon voiding of urine. During a recent study of bacterial colonization by the urinary pathogen, Proteus mirabilis, we noted that it colonized glass surfaces such that organisms became widely and evenly dispersed over the surface. In contrast, Pseudomonas fluorescens, a non-pathogen in the urinary tract, did not disperse over the surface but colonized and grew in such a manner as to form small clumps or microcolonies. Other investigators have also shown that Escherichia coli, a common urinary pathogen, initially colonizes bladders in a random, widely-dispersed fashion. We propose that successful bladder pathogens will predominantly adopt colonization behaviour that enables them to widely disperse over bladder tissue and, in so doing, avoid being cleared by the desquamation of uroepithelial cells. Colonization behaviour would therefore represent a previously uncharacterized virulence strategy.

Gentamycin beads in the treatment of localised vascular graft infection--long term results in 17 cases

Seventeen patients were treated by the implantation of gentamycin beads for localised Szilagyi type III prosthetic graft infection. Three patients had a pan prosthetic infection and half of the remaining patients were cured, but three of these died from other causes within 3 months. The mean observation time of the four survivors was 20 months (7-39 months). One of the seven patients, in whom the gentamycin beads failed, died of infection, giving a total mortality rate of 6% (1.5-29%). The remaining patients were cured after resection of the infected segment of the prosthesis at a mean follow-up of 22 months (8-37 months).

[The enterotoxigenic capacity of hemolysin-producing strains of Proteus isolated in acute intestinal infections in children]

The capacity of P. mirabilis and P. vulgaris strains isolated in acute enteric infections in children for producing enterohemolysin, a new type of hemolysin, has been shown. The relationship between the capacity of Proteus cultures for producing enterohemolysin and their capacity for inducing toxic secretory reaction on a ligated loop on the small intestine of rabbits in the absence of known thermostable and thermolabile antitoxin in bacteria.

Bacteremia and subcutaneous abscess caused by Proteus penneri in a neutropenic host

Proteus penneri bacteremia and concomitant subcutaneous infection developed in a neutropenic patient with acute lymphocytic leukemia. The skin infection occurred while the patient was being treated empirically with cefoperazone and metronidazole. This case demonstrates the invasive potential of this microorganism in the proper setting.