Short article: Successful faecal coliform sensitivity-based oral ertapenem therapy for chronic antibiotic-refractory pouchitis: a case series

Pouchitis is a common complication of restorative proctocolectomy for ulcerative colitis, and a proportion of patients develop a refractory course. The treatment of chronic antibiotic-refractory pouchitis (CARP) is challenging, and treatment failure is often a cause of pouch excision. We report on a series of three patients with CARP who were treated with oral ertapenem following faecal coliform sensitivity testing. There was an improvement in the pouchitis disease activity index in all three patients [pretreatment pouch disease activity index, median 13 (range: 10-14); post-treatment pouch disease activity index, median 1 (range: 1-3)]. Identification of faecal coliform sensitivity and treatment with oral ertapenem might be helpful in patients with CARP.

Endophthalmitis after penetrating keratoplasty

PURPOSE

To determine the incidence of endophthalmitis after penetrating keratoplasty (PK) and patient and donor risk factors.

DESIGN

Retrospective cohort study using national transplant registry data.

PARTICIPANTS

All corneal transplant recipients (n = 11 320) registered on the United Kingdom Transplant Registry undergoing their first PK between April 1999 and December 2006.

METHODS

Patients who developed endophthalmitis were identified on the transplant registry. In addition, cases where the fellow cornea from the same donor had been transplanted were included. Clinical information regarding donor and recipient characteristics, surgical details, and postoperative outcomes were collected and analyzed. In cases where endophthalmitis was reported, the diagnosis was verified by a follow-up supplementary questionnaire to the surgeon. Logistic regression was used to investigate differences in the factors associated with the development of endophthalmitis.

MAIN OUTCOME MEASURES

Incidence of endophthalmitis and graft survival.

RESULTS

The overall incidence of endophthalmitis occurring after primary PK in the UK was 0.67%. The incidence of endophthalmitis occurring within 6 weeks of surgery was 0.16%. Graft survival after endophthalmitis was 27% (95% confidence interval, 16-38) at 5 years, with a mean best-corrected visual acuity of 1.13 (logarithm of the minimum angle of resolution) for surviving grafts. Factors associated with endophthalmitis were donor cause of death (infection), high-risk cases, and indication for corneal transplantation.

CONCLUSION

Endophthalmitis remains a serious issue, with those affected having reduced graft survival and poor visual outcomes. Management of the identified recipient and donor risk factors are important to reduce endophthalmitis risk. In particular, the increased incidence of endophthalmitis when the donor dies of infection requires further explanation and review of current donor eye retrieval and eye bank practices. The delayed presentation of endophthalmitis cases also raises questions regarding possible sequestration of microbes within the corneal tissue and the effect of antimicrobials in storage media.

Genotypic analysis of UK keratitis-associated Pseudomonas aeruginosa suggests adaptation to environmental water as a key component in the development of eye infections

To examine temporal dynamics of corneal infection (keratitis)-associated Pseudomonas aeruginosa, we compared the genetic characteristics of isolates collected during two different time periods (2003-2004 and 2009-2010) using an ArrayTube genotyping system. The distribution of keratitis-associated isolates from the two studies (n = 123) among a database of P. aeruginosa strains of non-ocular origin (n = 322) indicated that 71% of UK keratitis-associated P. aeruginosa isolates clustered together, and there was no evidence for major variations in the distribution of clone types between the two collections. Our analysis indicates the presence of a 'core keratitis cluster', associated with corneal infections, that is related to the P. aeruginosa eccB clonal complex, which is associated with adaptation to survival in environmental water. This suggests that adaptation to environmental water is a key factor in the ability of P. aeruginosa to cause eye infections.

An unexpected diagnosis of methicillin-resistant Staphylococcus aureus septic arthritis

Hand infections can result in serious tissue damage and gross functional impairment. This is particularly true in the case of septic arthritis, the most destructive of all joint disease. We report the first case of methicillin-resistant Staphylococcus aureus septic arthritis of the distal interphalangeal joint to have occurred in a patient devoid of all risk factors traditionally associated with a hospital-associated infection (HA-MRSA). The afflicted patient's only exposure to the pathogen was during her role as a community carer for an asymptomatic carrier. Delayed treatment allowed the infection to rapidly destroy surrounding soft tissue and necessitate in the need for arthrodesis. It is, therefore imperative that clinicians maintain a low index of suspicion for methicillin-resistant Staphylococcus aureus as the causative pathogen in similar cases. Consequently, consideration of empirical antibiotic therapy for this patient subgroup is discussed.

Staphylococcus aureus with reduced glycopeptide susceptibility in Liverpool, UK

OBJECTIVES

To investigate if colonization with heterogeneous glycopeptide-intermediate Staphylococcus aureus (hGISA) is associated with hGISA bacteraemia.

METHODS

Isolates of methicillin-resistant S. aureus (MRSA) from blood cultures and from swabs to detect MRSA colonization were screened for reduced susceptibility to glycopeptides by an agar incorporation method. Isolates detected by this screen were tested for glycopeptide resistance by MacroEtest, standard MIC Etest methods and population analysis profile-AUC (PAP-AUC) analysis. S. aureus isolates with and without reduced glycopeptide susceptibility were characterized by PFGE and spa typing.

RESULTS

MRSA isolates with reduced susceptibility to glycopeptides, as identified by the MacroEtest method, were detected in the colonization screens of 86 of 2550 MRSA-positive patients. The isolates were confirmed by Etest MIC and PAP-AUC analysis as hGISA. A total of 82/86 of the hGISA colonizing isolates were EMRSA-16 by PFGE; the remainder were EMRSA-15. Bacteraemia with hGISA was identified in five patients during the study period; two isolates were EMRSA-16 and three were EMRSA-15. hGISA colonization could not be linked to hGISA bacteraemia and hGISA bacteraemia could not be linked to hGISA colonization. Four of the five hGISA bacteraemias developed following teicoplanin therapy for a central venous catheter-associated MRSA bacteraemia.

CONCLUSIONS

Laboratory strategies to reduce morbidity associated with hGISA should focus on testing for hGISA in bacteraemic (rather than colonizing) MRSA isolates in patients with recurrent S. aureus bacteraemia following glycopeptide exposure.

Emergence of high-level azithromycin resistance in Neisseria gonorrhoeae in England and Wales

OBJECTIVES

This study aimed to investigate the origin of high-level azithromycin resistance that emerged in isolates of Neisseria gonorrhoeae in England and Wales in 2007, and to establish methods for identifying high-level azithromycin resistance.

METHODS

The Gonococcal Resistance to Antimicrobials Surveillance Programme (GRASP) data from 2001-07 were examined for emerging trends in azithromycin susceptibility. Further to the identification of six high-level azithromycin-resistant isolates in GRASP 2007, an additional 102 isolates were selected on the basis of azithromycin susceptibility and geographic origin from the GRASP 2006 and 2007 collections. Susceptibility testing by Etest and disc diffusion was performed on all 108 isolates and 75 of these were typed by N. gonorrhoeae multiantigen sequence typing.

RESULTS

A slight drift towards higher MICs of azithromycin was observed in the gonococcal population since 2001. Of greater concern was the first example of a shift to high-level resistance observed in six isolates in 2007. All six isolates were sequence type 649, which was not observed in any of the lower-level azithromycin-resistant isolates from 2007 or in any isolates tested from the same geographical locations. Contact tracing data for one patient suggested a link with Scotland. Disc diffusion testing of all 108 isolates showed that azithromycin, but not erythromycin, discs can differentiate between low-level and high-level resistance.

CONCLUSIONS

High-level azithromycin resistance has emerged in England and Wales. Contact tracing and typing data suggest this may have originated from Scotland. Surveillance of azithromycin resistance will be key in controlling its further dissemination.

In vivo development of heterogeneous glycopeptide-intermediate Staphylococcus aureus (hGISA), GISA and daptomycin resistance in a patient with meticillin-resistant S. aureus endocarditis

We report a patient who developed a meticillin-resistant Staphylococcus aureus (MRSA) central venous catheter infection complicated by infective endocarditis. The patient was initially treated with glycopeptides, which led to the development of heterogeneous glycopeptide resistance, the detection of which required the use of a macro Etest screening test. Subsequently, the causative strain, confirmed by PFGE as a UK epidemic MRSA-15, was treated with daptomycin, and again resistance developed in vivo. The development in vivo of resistance to both these agents suggests that the resistance mechanisms may be associated. We suggest that the clinician managing MRSA infection should anticipate daptomycin resistance when reduced glycopeptide susceptibility is detected.

Genotypic and phenotypic characteristics of Pseudomonas aeruginosa isolates associated with ulcerative keratitis

A collection of 63 isolates of Pseudomonas aeruginosa associated with ulcerative keratitis, collected from six centres in England, were typed using serotyping and random amplified polymorphic DNA-PCR, and screened for several variable virulence-related genotypes and phenotypes. Sixty-one percent of the isolates were of either serotype O1 or serotype O11, but there was no evidence for a common clone. The majority of isolates (59%) were PCR-positive for exoU rather than for exoS (38%), and carried a-type fliC genes (76%) rather than b-type (24%). Isolates were PCR-positive for pyoverdine-receptor types at a prevalence of 38% for type I, 46 % for type II and 8 % for type III. All but one of the isolates exhibited twitching activity. There was a correlation between the presence of exoS and twitching activity (P = 0.04), suggesting that a combination of exoS genotype and good twitching activity may have a role to play in ExoU-independent corneal virulence.

Molecular epidemiology of endemic ciprofloxacin-resistant Neisseria gonorrhoeae in Liverpool

Ciprofloxacin-resistant Neisseria gonorrhoeae had been rarely detected on Merseyside and when found was associated with beta-lactamase producing strains, imported from abroad. However, in August 2000, two cases of infection with ciprofloxacin-resistant beta-lactamase-negative strains occurred in sexually unrelated patients with no history of foreign travel. Over the next 18 months a total of 120 patients presented with ciprofloxacin-resistant gonococci, from which 99 patient strains were available for study. Gonococcal DNA was subjected to molecular fingerprinting by polymerase chain reaction amplification followed by Taq1 digestion of their opa genes. Twelve differing opa-types were found, but 79 patients were infected with a single genotype, opa-type 1. The sexual histories of the majority of this group indicated acquisition in Merseyside. This endemic strain was further characterized by having the same amino acid substitutions on gyrA and parC genes. An endemic clone of ciprofloxacin-resistant N. gonorrhoeae has been established on Merseyside necessitating the introduction of ceftriaxone as first-line treatment. Despite the presence of 11 other clones in the city, opa type-1 strains have not yet been displaced, raising the possibility that this strain is endowed with added virulence/endemicity traits or that a number of source patients have not yet been found.

Risk factors for invasive fungal infection in neonates

Invasive fungal infection is an uncommon, but increasing cause of morbidity and mortality in neonates. There are few controlled studies defining risk factors for the development of fungal infection in a contemporary neonatal population. This retrospective case-control study was undertaken to investigate antenatal, demographic and postnatal variables that may be potentially important in the development of fungal infection. Two gestation-matched controls were identified for each index case. Information about perinatal and demographic variables, as well as important neonatal outcomes, was obtained from case notes. Microbiological data collected included the presence of fungal colonization, and organisms responsible for invasive fungal infection. Over a 5-y period, 24 infants with invasive fungal infection and 48 controls were identified. Candida albicans was the organism identified in 75% of cases of fungal septicaemia, and in all cases complicated by fungal meningitis. Preceding fungal colonization, pulmonary haemorrhage and intrauterine growth restriction were factors significantly and independently associated with invasive fungal infection. Fifty-four percent of infants with invasive fungal infection died, and 82% of survivors developed chronic lung disease.

CONCLUSION

Some new and potentially important risk factors for the development of invasive fungal infection in a contemporary population of infants admitted to a neonatal intensive care were identified.

Time to positivity of neonatal blood cultures

AIM

To determine how long it takes neonatal blood cultures to become positive.

METHODS

Data were collected retrospectively on 451 positive blood cultures from babies on a tertiary neonatal unit between January 1997 and December 1998. During the study period, the laboratory used the BacT/Alert microbial detection system.

RESULTS

Complete information was available on 416 blood cultures. Twelve became positive after 72 hours, none of which were considered to be clinically significant. Of the 404 remaining cultures, 86% were positive at 36 hours, 96% at 48 hours, and 98.5% by 60 hours. If definite bacterial pathogens are considered alone, the time to positivity was 90% by 36 hours, 93% by 48 hours, and 98% by 60 hours. If definite and possible bacterial pathogens are considered (coagulase negative staphylococci taken as possible bacterial pathogens), the time to positivity was 89% at 36 hours and 97% at 48 hours. The negative predictive value, for isolation of any organism before 72 hours, of a negative blood culture was 97% at 36 hours and 99% at 48 hours. The negative predictive value for the isolation of definite bacterial pathogens only was 99.7% at 36 hours and 99.8% at 48 hours.

CONCLUSIONS

A period of 36 hours is enough to rule out sepsis in the asymptomatic neonate, and a three day incubation period is sufficient to detect all clinically important infections using the BacT/Alert microbial detection system.

Magnetic interactions in the high-spin iron(III) oxooctaethylchlorinato derivative [Fe(oxoOEC)(Cl)] and its pi-cation radical [Fe(oxoOEC.)(Cl)]SbCl6

The preparation and characterization of the beta-oxochlorin derivative [3,3,7,8,12,13,17,18-octaethyl-(3H)-porphin-2-onato(2-)]iron(III) chloride, [Fe(oxoOEC)(Cl)], and its pi-cation radical derivative [Fe(oxoOEC.)(Cl)]SbCl6 is described. Both compounds have been characterized by single-crystal X-ray structure determinations, IR, UV/vis/near-IR, and Mössbauer spectroscopies, and temperature-dependent magnetic susceptibility measurements. The macrocycles of [Fe(oxoOEC)(Cl)] and [Fe(oxoOEC.)(Cl)]SbCl6 are both saddled, and [Fe(oxoOEC.)(Cl)]-SbCl6 is slightly ruffled as well. [Fe(oxoOEC)(Cl)] shows a laterally shifted dimeric unit in the solid state, with a mean plane separation of 3.39 A and a lateral shift of 7.39 A. Crystal data for [Fe(oxoOEC)(Cl)]: triclinic, space group P1, Z = 2, a = 9.174(2) A, b = 13.522(3) A, c = 14.838(3) A, alpha = 95.79(3) degrees, beta = 101.46(2) degrees, gamma = 104.84(3) degrees. Upon oxidation, the inter-ring geometric parameters increase; the mean plane separation and the lateral shift of the dimeric unit of [Fe(oxoOEC.)(Cl)]SbCl6 are 4.82 and 8.79 A, respectively. Crystal data for [Fe(oxoOEC.)(Cl)]SbCl6: monoclinic, space group Cc, Z = 4, a = 19.8419(13) A, b = 10.027(2) A, c = 22.417(4) A, beta = 96.13(2) degrees. A broad near-IR absorption band appears at 1415 nm for the pi-cation radical, [Fe(oxoOEC.)(Cl)]SbCl6. Zero-field Mössbauer measurements at 4.2 K for both [Fe(oxoOEC)(Cl)] and [Fe(oxoOEC.)(Cl)]SbCl6 confirmed that the oxidation state of the iron atom did not change upon chemical oxidation. Solid-state magnetic susceptibility measurements for [Fe(oxoOEC.)(Cl)]SbCl6 resulted in a large temperature dependence of the magnetic moment that can best be fit with a model that includes a zero-field splitting parameter of D = 6 cm-1, antiferromagnetic intermolecular iron-iron coupling (2JFe-Fe = -0.14 cm-1), antiferromagnetic intramolecular iron-radical coupling (2JFe-r = -76 cm-1), and antiferromagnetic radical-radical coupling (2Jr-r = -13 cm-1).

Serratia marcescens pseudobacteraemia in neonates associated with a contaminated blood glucose/lactate analyzer confirmed by molecular typing

Three episodes of Serratia marcescens pseudobacteraemia occurred on a neonatal intensive care unit. Following the first two cases, one full term and one pre-term infant, the source was identified as a glucose/lactate analyzer. Blood culture and environmental isolates of the organisms involved were indistinguishable when subjected to pulsed-field gel electrophoresis of Spe 1 digests and PCR ribotyping. Failure to recognize pseudobacteraemia in neonates results in inappropriate therapy for the individual and increased antibiotic pressures on the unit. Attention to the possibility of cross infection when using automated analyzers is required to minimize the risks of true or pseudoinfection to patients.

An assessment of triclosan susceptibility in methicillin-resistant and methicillin-sensitive Staphylococcus aureus

Triclosan is widely used to reduce skin colonization with staphylococci and is incorporated into methicillin-resistant Staphylococcus aureus (MRSA) eradication regimes. Using an agar dilution method, the minimum inhibitory concentration (MIC) to triclosan was determined for 186 isolates of MRSA and methicillin sensitive Staphylococcus aureus (MSSA). Fourteen isolates (7.5%) were detected with a MIC > or = 1.0 part per million (ppm). There was no significant difference between the incidence of triclosan resistance in strains of MSSA and MRSA. None of 16 strains of MRSA which exhibited low-level mupirocin resistance had MIC's > or = 1.0 ppm. Increased MIC's of staphylococci to triclosan may contribute to treatment failure when used to eradicate staphylococcal carriage. We suggest that routine susceptibility testing of staphylococci against triclosan might now be indicated.

Evaluation of CHROMagar orientation medium for the identification of surveillance cultures: a novel method

Microbiological surveillance helps prevent the spread of potentially pathogenic organisms on high-risk units. This study describes a simple method for identifying aerobic Gram-negative bacilli isolated from a neonatal intensive care unit screening programme. The identification scheme combines CHROMagar with three commonly used laboratory tests and multipoint technology. The procedure produced identical results when compared with an established identification method (Mast ID) over a three-week period. Financial evaluation suggests that significant cost savings could be achieved with the new scheme.

Blood culture volume and detection of coagulase negative staphylococcal septicaemia in neonates

A prospective, blind study was carried out to determine: the amount of blood submitted for culture from neonates; whether small blood volumes resulted in false negative results; and whether there was a temporal relation between volume of blood cultured and time to positivity. Seventy three bottles were evaluated. They contained a median of 0.63 ml of blood. Twenty nine bottles (39.7%) contained less than 0.5 ml of blood; 21 bottles (28.8%) were positive. There were three false negative cultures, only one of which contained a blood volume below 0.5 ml. The median time to positivity was 22.4 hours. There was no correlation between blood volume cultured and time to positivity. Neonatal cultures frequently contain less than 0.5 ml of blood. False negative cultures are rare. Neonatal blood culture bottles need to be validated for blood volumes below 0.5 ml.

Post-exposure prophylaxis after needlestick injuries would require change in management

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Microbial characteristics and severity of coagulase-negative staphylococcal septicaemia in premature neonates

A pilot study was undertaken to assess the predictive value of characteristics possessed by coagulase-negative staphylococci in determining clinically important infection in premature neonates. No significant association was demonstrated between organism properties and clinical indices of infection. The routine use of simple measures of microbial characteristics in the assessment of neonatal septicaemia is not warranted.

Spontaneously resolving Ureaplasma urealyticum meningitis

We report this case of a preterm infant with intraventricular haemorrhage who had Ureaplasma urealyticum isolated from the CSF together with a CSF pleocytosis both of which spontaneously cleared.

In-vitro activity of ten antimicrobial agents against penicillin-resistant Streptococcus pneumoniae

The minimum inhibitory concentrations (MICs) of ten antibiotics were determined by the agar dilution method for 40 strains of penicillin-resistant Streptococcus pneumoniae, all of which were clinical isolates from this laboratory. The antibiotics tested were clarithromycin, erythromycin, teicoplanin, vancomycin, ceftriaxone, cefodizime, azithromycin, ramoplanin, ciprofloxacin and MDL 62873. Of these agents, clarithromycin, vancomycin, teicoplanin, ceftriaxone, ramoplanin and MDL 62873 were the most active. The role of these antibiotics as alternatives to penicillin for the treatment of infections caused by penicillin-resistant S. pneumoniae is discussed.