The Prevalence and Automated Identification of Microorganisms Isolated from Clinical Samples in Kalar City

Polymicrobial Peritonitis in Peritoneal Dialysis Patients in Australia: Predictors, Treatment, and Outcomes

To determine the causative agents of infections and their antimicrobial susceptibility at a tertiary care hospital in Moshi, Tanzania, to guide optimal treatment. A total of 590 specimens (stool (56), sputum (122), blood (126) and wound swabs (286)) were collected from 575 patients admitted in the medical and surgical departments. The bacterial species were determined by conventional methods, and disc diffusion was used to determine the antimicrobial susceptibility pattern of the bacterial isolates. A total of 249 (42.2%) specimens were culture-positive yielding a total of 377 isolates. A wide range of bacteria was isolated, the most predominant being Gram-negative bacteria: Proteus spp. (n = 48, 12.7%), Escherichia coli (n = 44, 11.7%), Pseudomonas spp. (n = 40, 10.6%) and Klebsiella spp (n = 38, 10.1%). Wound infections were characterised by multiple isolates (n = 293, 77.7%), with the most frequent being Proteus spp. (n = 44, 15%), Pseudomonas (n = 37, 12.6%), Staphylococcus (n = 29, 9.9%) and Klebsiella spp. (n = 28, 9.6%). All Staphylococcus aureus tested were resistant to penicillin (n = 22, 100%) and susceptible to vancomycin. Significant resistance to cephalosporins such as cefazolin (n = 62, 72.9%), ceftriaxone (n = 44, 51.8%) and ceftazidime (n = 40, 37.4%) was observed in Gram-negative bacteria, as well as resistance to cefoxitin (n = 6, 27.3%) in S. aureus. The study has revealed a wide range of causative agents, with an alarming rate of resistance to the commonly used antimicrobial agents. Furthermore, the bacterial spectrum differs from those often observed in high-income countries. This highlights the imperative of regular generation of data on aetiological agents and their antimicrobial susceptibility patterns especially in infectious disease endemic settings. The key steps would be to ensure the diagnostic capacity at a sufficient number of sites and implement structures to routinely exchange, compare, analyse and report data. Sentinel sites (hospitals) across the country (and region) should report on a representative subset of bacterial species and their susceptibility to drugs at least annually. A central organising body should collate the data and report to relevant national and international stakeholders.

Incidence of antimicrobial resistance among Gram-positive organisms has been increasing steadily to most of the currently available anti bacterials, making it extremely difficult to treat infections. Purpose of this study was to assess the epidemiology of infections caused by multi-drug resistant (MDR) Gram positive isolates in India and to survey response of antimicrobial agents to these strains. This study involved 408 Gram positive isolates including S. aureus (211), Methicillin-resistant Staphylococcus aureus (MRSA) (130), Staphylococcus epidermidis (15), Streptococcus pneumoniae (12), Streptococcus pyogenes (13), Streptococcus bovis (7), Streptococcus agalactiae (9) and Enterococcus faecalis (11) which were collected from different parts of India. Susceptibility study was performed by broth microdilution method as recommended by Clinical and laboratory standard institutes (CLSI). Our study revealed that Vancoplus is the most effective with > 90 % susceptibility to most of the pathogens like S. aureus, MRSA and S. epidermidis with MICs 0.0625-2 µg/ml followed by linezolid with ≤ 85 % susceptibility to the said pathogens with MICs 1-4 µg/ml. The susceptibility of other drugs varied between 19 to 84 %. Among streptococcus, the susceptibility of Vancoplus varied between 91 to 100% with MICs 0.3125 to 1 µg/ml whereas linezolid showed 66 to 84 % susceptibility with MICs 0.5-4 µg/ml. The susceptibility of other drugs ranged between 23 to 71 %. About 90.9 % E. faecalis isolates were susceptible to Vancoplus at 0.0625-4 µg/ml compared to 81.8% to Linezolid, around 72% to vancomycin, daptomycin and teicoplanin and only 27.3% to clindamycin In conclusion, Vancoplus demonstrated potent in vitro activity against Gram-positive staphylococcal, streptococcal and enterococcal isolates. The results of this surveillance study can serve as a benchmark for monitoring the in vitro activity of this new agent.

To review the incidence, distribution, current trends, and resistance patterns of bacterial keratitis isolates in Toronto over the past 16 years. Microbiology records of suspected bacterial keratitis that underwent a diagnostic corneal scraping and cultures from January 1, 2000, through December 31, 2015, were retrospectively reviewed. The distribution of the main isolated pathogens and in vitro laboratory minimum inhibitory concentration testing results were used to identify resistance patterns. A total of 2330 corneal scrapings were taken over 16 years. A pathogen was recovered in 1335 samples (57.3%), with bacterial keratitis accounting for 1189 of the positive cultures (86.0% of all isolates). The total number of gram-positive and gram-negative isolates was 963 and 324, respectively. Coagulase-negative Staphylococcus and Pseudomonas aeruginosa were the most common gram-positive and gram-negative bacteria isolates, respectively. A decreasing trend in the number of isolates in gram-positive bacteria (P = 0.01), specifically among Staphylococcus aureus (P < 0.0001) and Streptococcus species (P = 0.005), was identified. When analyzing the susceptibilities of gram-positive and gram-negative isolates, an increasing trend in antibiotic resistance was observed in erythromycin (P = 0.018), ceftazidime (P = 0.046), and piperacillin/tazobactam (P = 0.005). The susceptibility of tested gram-positive microorganisms to vancomycin was 99.6%. There has been a decreasing trend in the number of isolates in gram-positive microorganisms over the past 16 years. An increasing trend in resistance for various antibiotics against gram-negative and gram-positive isolates was identified. High susceptibility to vancomycin reinforced the empirical use of fortified tobramycin and vancomycin in the initial management of severe bacterial keratitis.

Objective To analyze the clinical features of neonatal purulent meningitis (NPM) caused by Gram-positive and Gram-negative bacteria. Method From January 2008 to December, 2015, the clinical data of NPM with positive cerebrospinal-fluid (CSF) culture admitted to Children′s Hospital of Fudan University were reviewed retrospectively. Patients were assigned into Gram-positive group and Gram-negative group according to CSF culture, and general information, clinical presentation, laboratory examination and outcome were compared between the two groups. Wilcoxon Rank-Sum test was used to compare means. Proportions were compared using χ2 test. Result A total of 82 NPM patients with positive CSF culture were enrolled in the study, and 44 (53.7%) were male. The average gestational age was 38.5 (35.6, 39.6) weeks and the mean birth weight was 3 100 (2 600, 3 380) grams. 16 (19.5%) cases were early-onset meningitis and 66(80.5%) were late-onset. In 82 cases, 43 (52.4%) showed Gram-positive bacteria and 39(47.6%) Gram-negative in CSF culture. The five most common pathogens were escherichia coli(22 cases, 26.8%), group B streptococcus (GBS) (10 cases, 12.2%), enterococcus faecium (8 cases, 9.8%), coagulase-negative staphylococcus(8 cases, 9.8%) and klebsiella pneumoniae(5 cases, 6.1%). In early-onset patients, the main causative pathogens isolated from CSF were GBS (3 cases, 18.8%) and enterococcus (3 cases, 18.8%) . Escherichia coli (20 cases, 30.3%) and coagulase-negative staphylococcus(8 cases, 12.1%) were the most common pathogens in late-onset patients. Gram-positive group and Gram-negative group had similar clinical presentation(P>0.05). The ratio of patients with blood C-reactive protein>8 mg/L in Gram-negative group was higher than that in Gram-positive group(P<0.05). Those with Gram-negative bacterial meningitis had a higher incidence of hydrocephalus than Gram-positive (P<0.05). Conclusion The main pathogens of NPM are escherichia coli and GBS. Neonates with Gram-positive bacteria meningitis have similar clinical presentation with those with Gram-negative meningitis, but have different laboratory examination and complication characteristics. Key words: Meningitis, bacterial; Gram-positive bacteria; Gram-negative bacteria; Clinical features

Objective To investigate the distribution and drug resistance of microbial pathogens in midstream specimen of urine of patients with urinary tract infection, provide reference and basis for clinical medication. Methods A total of 1 348 urine specimens were in this study. These specimens were collected from more than 500 basic level hospitals in June 2015 to May 2016. These hospitals distributed in 13 cities of Jiangsu province. The urine specimens were cultured on blood agar and MacConkey Agar respectively. VITEK COMPACT automatic microbial analysis system and API identification strip for bacterial identification were utilized. Strain identification were carried out when the isolated gram negative bacteria was more 105 cfu/ml and gram positive bacteria was more than 104 cfu/ml. Drug sensitivity test results were determined by CLSI(2015). Results Microbial pathogens were isolated from 450 specimens accounted 33.38% of the all (450/1 348). Three hundred fifty-eight strains of gram negative bacteria was isolated, account for 79.56% of all strains (358/450). Seventy-six strains of gram positive bacteria were isolated. Sixteen strains of fungi were also isolated, only account for 3.56% of all (16/450). Drug sensitivity test showed that the resistance rates of E. coli to ampicillin, piperacillin, cefazolin, cefuroxime were 84.16%, 80.37%, 87.12% and 93.98% respectively; the resistance rates of Enterococcus to tetracycline, rifampin, quinupristin-dalfopristin, minocycline were 81.40%, 86.67%, 100% and 83.33% respectively. Conclusions E.coli and Enterococcus faecalis are the the main pathogens of urinary tract infections. Drug resisitance to penicillin, cephalosporins, tetracyclines and rifamycin is greater. These results provide instructional significance to rational use of antimicrobial agents Key words: Urinary tract infection; Urine culture; Pathogens; Durg resistance

Introduction. Vaginal colonization of Group B Streptococcus (GBS) is associated with preterm births and neonatal sepsis. Thus routine screening of GBS in prenatal care is recommended.Hypothesis. Chromogenic media (carrot broth) aids in specific and rapid detection of GBS.Aim. To investigate the efficiency of Strep B Carrot Broth for detection of GBS in high vaginal swabs from pregnant women.Methods. In this study 201 vaginal swab samples were collected from pregnant women. Swabs were inoculated in chromogenic media (Strep B Carrot Broth). The positive and negative cultures were inoculated on blood agar and crome agar plates. The colonies were subjected to 16S rRNA sequencing and gene-specific PCR for confirmation. The Christie Atkins Munch Peterson (CAMP) and bile esculin agar (BEA) tests were used for biochemical confirmation. PCR was performed on genomic DNA isolated from uncultured vaginal swabs.Results. It was found that 20/201 (9.9 %) vaginal swab samples were positive in the Strep B Carrot Broth and 17/20 (85 %) and 19/20 (95 %) of these samples yielded colonies on blood agar and crome agar, respectively. Of the 181 carrot broth-negative samples, 1 (0.5 %) and 38 (20.9 %) yielded colonies on blood agar and crome agar plates, respectively. However, 16 s rRNA sequencing revealed that none of the 20 carrot broth-positive cultures were GBS and had sequence similarities to Enterococcus faecalis. This was also confirmed by using gene-specific PCR and BEA positivity. Furthermore, E. faecalis was detected by PCR in DNA isolated from 57 uncultured vaginal swabs samples, GBS could only be detected by PCR in four samples.Conclusion. Carrot broth-based culture can lead to false-positive detection due to the presence of E. faecalis. Thus GBS-positive results in carrot broth must be confirmed by the other molecular and biochemical tests before making a final diagnosis.

Objectives: The purpose of this study was to isolate and speciate Candida from various clinical samples and compare the colony characteristics of isolated Candida species on CHROMagar with the corn meal agar (CMA). Methods: In our prospective study conducted for the duration of 6 months from February 2023 to July 2023, 81 Candida isolates were obtained from various clinical specimens such as high vaginal swab, blood, pus, skin scrapings, sputum, bronchoalveolar lavage (BAL), and endotracheal secretions which were subjected to KOH mount and then subcultured on Sabouraud’s dextrose agar (SDA) with chloramphenicol and incubated aerobically at 37°C for 24–48 h. From the growth on SDA, further inoculation was done on CHROMagar and CMA, followed by additional identification and susceptibility through Vitek-2, and three were compared in terms of their sensitivity and specificity for isolation of various Candida species. Results: Maximum Candida isolates were obtained from blood (18), followed by high vaginal swabs (17), pus (12), and nail clippings (10), whereas a single isolate was recovered from a patient with otorrhea. The most common risk factor was found to be prolonged antibiotic therapy. NAC was isolated at a higher rate 42 (52%) than Candida albicans 39 (48%). Among non-albicans Candida (NAC), Candida tropicalis was the most common species isolated 21 (50%), followed by Candida parapsilosis 11 (26%), Candida glabrata 5 (12%), Candida krusei 2 (4.7%), and C. tropicalis, which was predominant species isolated in blood 13/18 (73%) followed by pus 9/12 (75%). C. albicans predominated in HVS 13/17 (76%), sputum sample 4/6 (67%), BAL 6/9 (66%), and ET secretions 2/3 (67%). Candida ciferrii was the only species isolated from ear discharge. Conclusion: CHROMagar showed more sensitivity in detection of C. albicans (100%) in comparison to CMA and Vitek-2 (97.4%) and decreased specificity (97.6%) as compared to CMA and Vitek-2 (100%) whereas for speciation of NAC particularly C. parapsilosis and C. glabrata CMA alone and also in combination with Vitek-2 exhibited much better sensitivity and specificity as compared to CHROMagar. NAC showed higher level of resistance to the azoles group of drugs and were overall less sensitive to other antifungal as compared to C. albicans. Hence, the amalgamation of cost-effective CMA with CHROMagar is an utmost need of an hour to give accurate yeast identification within the same time span.

To study the clinical characteristics, pathogenic bacteria, and antibiotics resistance of neonatal purulent meningitis in order to provide the guide for early diagnosis and appropriate treatment. A retrospective review was performed and a total of 112 cases of neonatal purulent meningitis (male 64, female 58) were identified in the neonatal intensive care unit of Yuying Children's Hospital of Wenzhou Medical University seen from January 1, 2004 to December 31, 2013. The clinical information including pathogenic bacterial distribution, drug sensitivity, head imageology and therapeutic outcome were analyzed. Numeration data were shown in ratio and chi square test was applied for group comparison. Among 112 cases, 46 were admitted from 2004 to 2008 and 66 from 2009 to 2013, 23 patients were preterm and 89 were term, 20 were early onset (occurring within 3 days of life) and 92 were late onset meningitis (occurring after 3 days of life). In 62 (55.4%) cases the pathogens were Gram-positive bacteria and in 50 (44.6%) were Gram-negative bacteria. The five most frequently isolated pathogens were Escherichia coli (32 cases, 28.6%), coagulase-negative staphylococcus (CNS, 20 cases, 17.9%), Streptococcus (18 cases, 16.1%, Streptococcus agalactiae 15 cases), Enterococci (13 cases, 11.6%), Staphylococcus aureus (9 cases, 8.0%). Comparison of pathogenic bacterial distribution between 2004-2008 and 2009-2013 showed that Gram-positive bacteria accounted for more than 50% in both period. Escherichia coli was the most common bacterium, followed by Streptococcus in last five years which was higher than the first five years (22.7% (15/66) vs. 6.5% (3/46), χ(2) = 5.278, P < 0.05). Klebsiella pneumoniae was more common isolate in preterm infants than in term infants (13.0% (3/23) vs. 1.1% (1/89), χ(2) = 7.540, P < 0.05). Streptococcus (most were Streptococcus agalactiae) was the most common bacteria in early onset meningitis and higher than those in late onset meningitis (35.0% (7/20) vs. 12.0% (11/92), χ(2) = 4.872, P < 0.05). Drug sensitivity tests showed that all the Gram-positive bacterial isolates were sensitive to linezolid. Staphylococci were resistant to penicillin, and most of them were resistant to erythromycin, oxacillin and cefazolin; 77.8%of CNS isolates were methicillin-resistant staphylococcus. No Streptococcus and Enterococcus faecalis was resistant to penicillin. None of enterococci was resistant to vancomycin. Among the Gram-negative bacterial isolates, more than 40% of Escherichia coli were resistant to commonly used cephalosporins such as cefuroxime, cefotaxime and ceftazidime, and all of them were sensitive to amikacin, cefoperazone sulbactam and imipenem. Isolates of Klebsiella pneumoniae were all resistant to ampicillin, cefuroxime, cefotaxime and ceftazidime, but none of them was resistant to piperacillin tazobactam and imipenem. Of the 112 patients, 69 were cured, 23 improved, 9 uncured and 11 died. There were 47 cases (42.0%) with poor prognosis, they had abnormal head imageology, severe complications and some cases died, 13 of 18 (72.2%) patients with meningitis caused by Streptococcus died. Escherichia coli, CNS and Streptococcus are the predominant pathogens responsible for neonatal purulent meningitis over the past ten years. There were increasing numbers of cases with Streptococcus meningitis which are more common in early onset meningitis with adverse outcome, therefore careful attention should be paid in clinic. Linezolid should be used as a new choice in intractable neonatal purulent meningitis cases caused by gram positive bacteria.

IntroductionEravacycline (ERV), a novel tetracycline derivative, exhibits broad-spectrum antibacterial activity, but data on the bacterial activity against Chinese bacterial isolates are very scarce. This study aims to evaluate the activity of eravacycline against the common Gram-positive and Gram-negative bacteria isolates in Guangdong, China.MethodsThe clinical isolates were collected from four centers between 1 November 2023 and 31 January 2024, and the susceptibility of eravacycline (MIC50, MIC90, and MIC) was determined using broth microdilution as a reference method and E-TEST strips to evaluate their consistency. A total of 594 strains were collected from the four centers, including Staphylococcus aureus (n = 126), Enterococcus faecalis (n = 58), Enterococcus faecium (n = 29), Klebsiella pneumoniae (n = 136), Escherichia coli (n = 187), and Acinetobacter baumannii (n = 58).Results and discussionThe MIC50 and MIC90 (mg/L) of eravacycline were 0.12 and 1 for S. aureus, 0.06 and 0.12 for E. faecalis, 0.06 and 0.5 for E. faecium, 0.25 and 0.5 for E. coli, 0.5 and 2 for K. pneumoniae, and 0.25 and 2 for A. baumannii. Based on the FDA and EUCAST breakpoints, the susceptibility of eravacycline against S. aureus was 46.03% vs. 83.33%, 56.90% vs. 94.93% against E. faecalis, and 62.07% vs. 79.31% in E. faecium. The susceptibility rates of E. coli and K. pneumoniae were 90.37% and 58.09, respectively. To evaluate the performance between the broth microdilution test (BMD) and ETEST methods, we compared essential agreement (EA), categorical agreement (CA), very major error (VME), and major error (ME). The results demonstrated that compared with BMD, eravacycline measured by ETEST had higher VME and ME referring to FDA breakpoints than EUCAST breakpoints in the Gram-positive isolates. Since there were no intermediate breakpoints for the eravacycline, the MIC values measured by the ETEST method might result in lower CA and higher VME and ME. This study provides MIC values of eravacycline against Gram-positive and Gram-negative pathogens in four hospitals in Guangdong Province, and eravacycline is an effective therapeutic candidate for common bacteria.

Surgical site infections (SSIs) are common nosocomial infections in surgical patients resulting in significant increases in postoperative morbidity and mortality. This study aimed to isolate and identify bacteria that cause SSIs in Medical Research Institute, Alexandria University, Egypt, and compare their sensitivities to selected group of antibiotics and natural products. Isolates from 20 patients with SSIs were identified by culturing on blood and MacConkey agars, Gram staining and biochemical reactions. Most Gram-negative isolates (Pseudomonas aeruginosa, Klebsiella spp, Acinetobacter spp) were sensitive to amikacin, imipenem. Gram-positive isolates were Enterococcus faecalis which was sensitive to chloramphenicol, vancomycin, and Staphylococcus aureus which was sensitive to amikacin, imipenem, chloramphenicol. Gram-negative isolates were more sensitive to olive oil at 70 and 100% concentrations, and Acinetobacter spp were resistant at 30% concentration. Gram-positive E. faecalis isolates were most sensitive at 30% concentration. Garlic and oregano oils were more effective against most Gram-positive and negative isolates. E. faecalis was resistant to garlic oil at 30% concentration.Klebsiella spp were resistant to Nigella sativa oil at all concentrations, Acinetobacter sppwere resistant at 30% concentration, and P. aeruginosa was more sensitive at all concentrations than Gram-positive isolates. P. aeruginosa and S. aureus were most sensitive, while Klebsiella spp were resistant to commercial oils (olive, garlic, and chamomile). Olive leaf extract was more effective at four concentrations against all Gram-negative isolates. Gram-positive and -negative isolates were most sensitive to whey mixed with honey. This study refers to the possibility of using olive, garlic and oregano oils, olive leaf extract, and whey mixed with honey in treatment of SSIs. Key words: Isolated bacteria, surgical wounds, natural herbal products.

Background: Gram-positive uropathogens have become common, associated with serious underlying illnesses and increasingly resistant to available antibiotics. Objectives: The goal of this study was to investigate the incidence and risk factors of gram-positive cocci UTIs in hospitalized patients in Medina, KSA and their susceptibility patterns to widely used antimicrobial agents. Methods: During a 12-month study, 165 clinical isolates of gram-positive cocci were recovered from 1137 culture-positive urine specimens at a tertiary hospital. Antimicrobial susceptibility of gram-positive cocci isolates was tested with the disk diffusion and E test methods. Molecular typing of some VRE isolates was done to detect the predominant Van genotypes. Results: Out of 8600 reviewed cases, 1137 (13.2%) were culture positive, 165 cases (14.5%) were gram positive cocci. E.faecalis formed 53.3% (88/165) of isolated gram-positive cocci, followed by E faecium (17.6%), S.agalactiae (23.6%) and S. aureus (5.5%). Multidrug resistant positive cocci formed 9.7% of gram-positive isolates including VRE (8.5%) and MRSA (1.2%). 75% of E. faecalis and 50% of E. faecium isolates were sensitive to nitrofurantoin, all VRE strains were sensitive to linezolid. All S. aureus isolates were sensitive to cefazolin, nirtofurantoin, sulfamethoxazole and vancomycin. 75% of MRSA strains were sensitive to sulfamethoxazole and all were sensitive to vancomycin. All isolates of S. agalactiae were sensitive to cefazolin and nitrofurantoin, and all were resistant to Trimethoprim-sulfamethoxazole. Van B genotype was detected. Conclusion: Vancomycin and nitrofurantoin seem to be effective drugs for treatment of gram positive UTIs. vanB genotype was detected.

Group B Streptococcus (GBS) causes significant morbidity and mortality in neonates, pregnant women and patients with underlying comorbidities. Intrapartum antibiotic prophylaxis (IAP) is currently the mainstay of prevention and effective vaccine against invasive GBS disease is under clinical trial. To describe the serotype distribution of invasive and colonizing GBS isolates in Sri Lanka. Probable GBS isolates from high vaginal swabs (HVS) and sterile body sites were collected from eight selected hospital laboratories. Following confirmation of the identification as group B Streptococcus by phenotypic methods including Lancefield grouping test (Plasmatic UK), isolates were tested for serotyping by latex agglutination test kit (STATEN serum institute, Denmark). Out of the 145 probable GBS isolates only 100 from HVS and 37 from sterile body sites were confirmed as GBS. Serotype III was the most predominant in invasive GBS isolates followed by Ia, Ib, VI, II and V in the descending order of frequency. Serotype VI was the most predominant in HVS isolates followed by serotype III, V, Ia, II, Ib and IV. Difference of GBS serotype distribution between the invasive and HVS group was statistically significant (P value = 0.038). Serotype distribution pattern of the study isolates was comparable to most of the other developing and developed countries and hence will be beneficial in future vaccine introduction. GBS vaccine which is currently under clinical trial (Ia, Ib and III) is potentially effective for preventing 68% of the early onset disease in neonates in this study setting.

Latex particle agglutination (LPA) testing for antigen to group B streptococcus (GBS) has been useful in the diagnosis of GBS sepsis in newborns. However, recent reports have demonstrated that the sensitivity of LPA assays may be as low as 27 to 54%. The purposes of the present study were to directly compare the abilities of four urine antigen assays to detect GBS antigen with clinical urine samples from neonates with GBS bacteremia and to evaluate the effect of the urine concentration on the sensitivities and specificities of these assays. Urine samples were collected serially from neonates with blood cultures positive for GBS or on admission from healthy full-term infants. One milliliter of urine was removed, and the remainder was concentrated to a volume of 1 ml. Unconcentrated samples were serially diluted with normal saline and were assayed to determine the highest dilution which would produce a positive test result. The Wellcogen, Bactigen, and Directigen LPA tests and ICON immunoassay were directly compared by using concentrated and unconcentrated urine specimens and urine specimens with known titers. A total of 94 urine specimens, including 61 concentrated and 75 unconcentrated specimens, from bacteremic infants were available for sensitivity testing, and 220 urine specimens from uninfected infants were available for specificity testing. There were significant differences in sensitivity among the four assays when they were performed on concentrated urine specimens, as follows: Directigen, 98%; Bactigen, 92%; ICON, 89%; Wellcogen, 68%. When the assays were performed on unconcentrated urine specimens, the Directigen (84%) and Bactigen (76%) assays were each significantly more sensitive than the ICON (59%) or Wellcogen (43%) assay. All four assays were significantly more sensitive in detecting GBS antigen in concentrated than in unconcentrated urine. The Directigen assay detected antigen in higher dilutions (geometric mean titer, 1:5) than the ICON (1:3), Bactigen (1.2), or Wellcogen (1:1) assay. The specificity was 99.5% for all four assays when concentrated urine was used and for the Bactigen, Directigen, and ICON assays when unconcentrated urine was used; the Wellcogen assay was 100% specific when unconcentrated urine was used. We conclude that there are significant differences in sensitivity but not specificity among the commercially available assays for the detection of GBS antigenuria when concentrated and unconcentrated urine specimens are tested. These differences in sensitivity may affect the abilities of clinicians to accurately diagnose GBS sepsis before culture results are available.

The revival of fosfomycin