The JK Diphtheroids

1986 ◽  
Vol 7 (9) ◽  
pp. 466-469 ◽  
Author(s):  
Paul E. Schoch ◽  
Burke A. Cunha
Keyword(s):  
Clinical Significance ◽  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
Beta Lactam ◽  
Cultural Characteristics ◽  
Gram Positive ◽  
Facultatively Anaerobic ◽  
Beta Lactam Antibiotics ◽  
Clinically Significant

In Bergey's manual, animal and human corynebacteria are a group of aerobic and facultatively anaerobic gram-positive or slightly curved bacilli that are generally nonmotile, catalase-positive, and non-acid fast. The best known and most clinically significant pathogen in the genus Corynebacterium is C. diphtheriae. However, other members of this genus are frequently encountered in the clinical laboratory and usually represent colonization or commensal contamination, since most other corynebacteria are of low virulence and questionable clinical significance. Frequently described as “diphtheroids,” such organisms are usually dismissed as contaminants and are not speciated or subjected to susceptibility testing. The JK diphtheroids may be differentiated from clinically unimportant “diphtheroids” by their resistance to beta-lactam antibiotics and their distinctive morphologic and cultural characteristics (Table 1).

scholarly journals Phenotypic detection of Carbapenamase among Klebsiella pneumoniae isolated from clinical samples using modified Hodged test

2020 ◽  
Vol 13 (3) ◽  
pp. 135-140
Author(s):  
HauwaYakubu ◽  
Mahmud Yerima Iliyasu ◽  
Asma’u Salisu ◽  
Abdulmumin Ibrahim Sulaiman ◽  
Fatima Tahir ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Susceptibility Testing ◽  
University Teaching ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Beta Lactam ◽  
Beta Lactamases ◽  
Beta Lactam Antibiotics ◽  
Microbiological Techniques ◽  
Tract Infections

Carbapenemases are microbial enzymes that confer resistance to virtually all available beta-lactam antibiotics and the most frequent carbapenemases are the Klebsiella pneumoniae Carbapenamase (KPC). Detection of carbapenemases is a significant infection control strategy as the enzymes are often associated with extensive antimicrobial resistance, therapeutic failures and mortality associated with infectious diseases. A total of 400 clinical samples were collected from different groups of patients in Abubakar Tafawa Balewa University Teaching Hospital, Bauchi, Nigeria and 118 K. pneumoniae were isolated using standard microbiological techniques. The isolates were subjected to antibiotic susceptibility testing by Kirby-Bauer disc diffusion method, then screened for Carbapenamase production using modified Hodge test. The results indicated that the isolates were resistant to Ampicillin (61.9%), Ceftriaxone (50.8%) and Ceftazidime (50.8%), then Ciprofloxacin (54.2%), but predominantly sensitive to Imipenem (66.9%), Eterpenem (60.2%) and Meropenem (65.3%). It was found that 38 (32.2%) of the isolates phenotypically shows the presence of Carbapenamase, with highest frequency of (40.7%) among patients, mainly adult females with cases of Urinary Tract Infections (UTIs) and the least from wound (11.8%).This study revealed that the isolates produced other beta-lactamases than KPC or variants of Carbapenamase that cannot be detected by modified Hodge test, thus shows low resistance to carbapenems. Therefore further studies is needed to genotypically confirm the presence of KPC in these isolates.

Rhodococcus Equi Pneumonia: Case Report and Literature Review

1993 ◽  
Vol 27 (11) ◽  
pp. 1340-1342 ◽  
Author(s):  
Bill C. Frame ◽  
Alan F. Petkus
Keyword(s):  
Lung Biopsy ◽  
Rhodococcus Equi ◽  
Hiv Positive ◽  
Cell Mediated Immunity ◽  
Reference Laboratory ◽  
Beta Lactam ◽  
Gram Positive ◽  
Beta Lactam Antibiotics ◽  
Case Summary ◽  
Emergence Of Resistance

OBJECTIVE: To present a case of Rhodococcus equi (RE) pneumonia and discuss its pathophysiology and treatment. CASE SUMMARY: An HIV-positive patient presented with pneumonia. A lung biopsy was performed after sputum and thoracentesis cultures failed to identify a pathogen. The lung biopsy revealed an unidentifiable, diphtheroid-like, gram-positive rod. A bronchoscopy performed five days after the lung biopsy produced the same diphtheroid-like, gram-positive rod. The patient was treated with several injectable antibiotics, but emergence of resistance to two of the antibiotics was suspected. Two weeks after the bacterial isolate was sent to a reference laboratory, it was identified as RE. The patient was discharged on oral antibiotics and experienced no recurrence of RE pneumonia. CONCLUSIONS: RE can be difficult to identify in the microbiology laboratory, or it may be assumed to be a colonizing diphtheroid. The isolation of difficult-to-identify, gram-positive rods, or diphtheroids, from a pulmonary source in a patient with decreased cell-mediated immunity should cause one to suspect RE. RE has been noted to develop resistance to beta-lactam antibiotics during therapy. A prolonged course of combination antibiotic therapy directed at the intracellular component of infection is necessary.

scholarly journals Surveillance of Antimicrobial Susceptibility of Anaerobe Clinical Isolates in Southeast Austria: Bacteroides fragilis Group Is on the Fast Track to Resistance

Antibiotics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 479
Author(s):  
Elisabeth König ◽  
Hans P. Ziegler ◽  
Julia Tribus ◽  
Andrea J. Grisold ◽  
Gebhard Feierl ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Anaerobic Bacteria ◽  
Bacteroides Fragilis ◽  
Beta Lactam ◽  
Gram Positive ◽  
Beta Lactam Antibiotics ◽  
Disk Diffusion Testing ◽  
Bacteroides Fragilis Group ◽  
Resistance Rates ◽  
Human Infections

Anaerobic bacteria play an important role in human infections. Bacteroides spp. are some of the 15 most common pathogens causing nosocomial infections. We present antimicrobial susceptibility testing (AST) results of 114 Gram-positive anaerobic isolates and 110 Bacteroides-fragilis-group-isolates (BFGI). Resistance profiles were determined by MIC gradient testing. Furthermore, we performed disk diffusion testing of BFGI and compared the results of the two methods. Within Gram-positive anaerobes, the highest resistance rates were found for clindamycin and moxifloxacin (21.9% and 16.7%, respectively), and resistance for beta-lactams and metronidazole was low (<1%). For BFGI, the highest resistance rates were also detected for clindamycin and moxifloxacin (50.9% and 36.4%, respectively). Resistance rates for piperacillin/tazobactam and amoxicillin/clavulanic acid were 10% and 7.3%, respectively. Two B. fragilis isolates were classified as multi-drug-resistant (MDR), with resistance against all tested beta-lactam antibiotics. The comparative study of 109 BFGI resulted in 130 discrepancies in 763 readings (17%) with a high number of Very Major Errors (VME) and Major Errors (ME). In summary, resistance rates, with the exception of clindamycin and moxifloxacin, are still low, but we are facing increasing resistance rates for BFGI. Surveillance studies on a regular basis are still recommended.

scholarly journals Metarrhizium anisopliae as a Cause of Sinusitis in Immunocompetent Hosts

1999 ◽  
Vol 37 (1) ◽  
pp. 195-198 ◽  
Author(s):  
Sanjay G. Revankar ◽  
Deanna A. Sutton ◽  
Stephen E. Sanche ◽  
Jyothi Rao ◽  
Marcus Zervos ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Susceptibility Testing ◽  
Chronic Sinusitis ◽  
Clinical Laboratory ◽  
Antifungal Susceptibility ◽  
National Committee ◽  
Insect Populations ◽  
Clinically Significant ◽  
Control Insect

Metarrhizium anisopliae is a common pathogen of insects and has even been used to control insect populations. It is rarely isolated from human or animal sources, but recently, there have been three reported cases of disease, two in humans and one in a cat. We present our experience with five isolates from human sources, including two that were the apparent causes of two cases of sinusitis in immunocompetent hosts. The first patient was a 36-year-old male with frontal and ethmoid sinusitis, and the second was a 79-year-old female with chronic sinusitis. Both patients underwent surgery, and pathology of the surgical specimens revealed branching hyphae. Cultures grew onlyMetarrhizium species. Neither patient received antifungal therapy, and both did well postoperatively. The other three isolates were cultured from bronchoalveolar lavage specimens but were not felt to be clinically significant. Antifungal susceptibility testing using the National Committee for Clinical Laboratory Standards macrobroth method revealed that all isolates were resistant to amphotericin B, 5-flucytosine, and fluconazole. Itraconazole and newer azole compounds were more active. Metarrhizium species may cause disease in humans, even those without evidence of immunosuppression, and are apparently highly resistant to amphotericin B in vitro.

scholarly journals Stenotrophomonas maltophilia susceptibility testing challenges and strategies

2021 ◽  
Author(s):  
Daniel D. Rhoads
Keyword(s):  
Stenotrophomonas Maltophilia ◽  
Susceptibility Testing ◽  
Beta Lactam ◽  
Commercial Test ◽  
Test Systems ◽  
Link Type ◽  
Beta Lactam Antibiotics ◽  
Challenges And Strategies

Stenotrophomonas maltophilia is intrinsically resistant to many beta lactam antibiotics including carbapenems and is resistant to aminoglycosides, which limits the therapeutic repertoire for managing S. maltophilia infections. Additionally, employing automated in vitro susceptibility testing of S. maltophilia is challenging because commercial test systems’ performance is limited (A. Khan, C. A. Arias, A. Abbott, J. Dien Bard, et al., J Clin Microbiol 59:e00654-21, 2021, https://doi.org/10.1128/JCM.00654-21 ). This commentary will briefly discuss the opportunity to use automated commercial susceptibility testing systems with S. maltophilia with a focus on how to practically implement their use while mitigating risk of error.

scholarly journals Cross-Canada Survey of Resistance of 2747 Aerobic Blood Culture Isolates to Piperacillin/Tazobactam and Other Antibiotics

1998 ◽  
Vol 9 (1) ◽  
pp. 33-44 ◽  
Author(s):  
Kevin R Forward ◽  
Patricia A Franks ◽  
Donald E Low ◽  
Robert Rennie ◽  
Andrew E Simor ◽  
...  
Keyword(s):  
Blood Culture ◽  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
Tertiary Care ◽  
Active Agent ◽  
Dilution Method ◽  
Highly Active ◽  
Facultative Anaerobic ◽  
Clinically Significant ◽  
Microbroth Dilution

OBJECTIVE: To compare the activity of piperacillin/tazobactam with that of other broad parenteral antibiotics against aerobic and facultative anaerobic blood culture isolates in a Canada-wide survey.DESIGN: Fifty-eight laboratories in nine provinces each contributed up to 50 consecutive clinically significant aerobic and facultative anaerobic isolates for susceptibility testing.SETTING: Participating hospitals included both tertiary care and community hospitals.MATERIALS AND METHODS: Testing was performed in five regional centres by using the same microbroth dilution method, and results were interpreted according to National Commitee for Clinical Laboratory Standards M7-A3 and M100-S5 guidelines.RESULTS: Piperacillin/tazobactam and imipenem were both active against more than 99% of the 1616 strains ofEnterobacteriaceaespecies tested. The minimum inhibitory concentration of 90% of isolates (MIC90) of allEnterobacteriaceaespecies was 2 mg/L for piperacillin/tazobactam compared with 64 mg/L for piperacillin alone. Seventeen per cent of strains ofEnterobacteriaceaespecies were susceptible to piperacillin/tazobactam but resistant to piperacillin. Piperacillin/tazobactam was highly active againstPseudomonas aeruginosa, inhibiting 99.1% of strains. MIC90was 8 mg/L. Nine per cent ofP aeruginosastrains were not susceptible to imipenem. Most of these strains had a MIC of 8 mg/L, which falls in the intermediate category. Ninety-seven per cent ofP aeruginosawere susceptible to ciprofloxacin and 97.3% to tobramycin. Ninety-six per cent of strains ofActinobacterspecies were susceptible to piperacillin/tazobactam, whereas only 76% of strains were susceptible to piperacillin alone. Overall, piperacillin/tazobactam was the most active agent tested; 98% of all strains were susceptible, followed closely by imipenem, to which 97.8% of strains were susceptible.CONCLUSIONS: Aerobic blood culture isolates from Canadian centres continue to be highly susceptible to a variety of antibiotics. The broad spectrum of activity of piperacillin/tazobactam suggests that this combination should be considered for empirical treatment of sepsis while awaiting results of cultures and susceptibility testing.

scholarly journals A Cross-Canada Surveillance of Antimicrobial Resistance in Respiratory Tract Pathogens

1999 ◽  
Vol 10 (2) ◽  
pp. 128-133 ◽  
Author(s):  
Ross J Davidson ◽  
Canadian Bacterial Surveillance Network ◽  
Donald E Low
Keyword(s):  
Antimicrobial Resistance ◽  
Clinical Laboratory ◽  
Clinical Isolates ◽  
National Committee ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Minimal Inhibitory Concentrations ◽  
Beta Lactam Antibiotics ◽  
Significant Difference ◽  
High Level

OBJECTIVE: To determine the prevalence of antimicrobial resistance in clinical isolates ofStreptococcus pneumoniae, Haemophilus influenzaeandMoraxella catarrhalisfrom medical centres across Canada.METHODS: Fifty laboratories from across Canada were asked to collect up to 25 consecutive clinical isolates ofS pneumoniae,H influenzaeandM catarrhalisat some time between September 1994 and May 1995, and then again between September and December of 1996. A total of 2364S pneumoniae, 575H influenzaeand 200M catarrhalissamples were collected.H influenzaeandM catarrhalisisolates were tested for the production of beta-lactamase.S pneumoniaeisolates were characterized as penicillin susceptible, intermediately resistant or high level penicillin-resistant. Minimal inhibitory concentrations (MICs) were determined using a microbroth dilution technique described by the National Committee of Clinical Laboratory Standards.RESULTS: Between the two collection periods, there was a significant increase in highly penicillin-resistantS pneumoniaefrom 2.1% to 4.4% (P<0.05) and an increase in intermediately penicillin-resistant strains from 6.4% to 8.9% (P<0.05). A significant increase in high level penicillin-resistantS pneumoniaewas noted among paediatric isolates. No significant difference in the susceptibilities of comparator agents was detected. A significant increase in the number of beta-lactamase producingH influenzae, 34% to 43% (P<0.05) was observed. Ninety-five per cent ofM catarrhalisisolates were beta-lactamase producers in both time periods.CONCLUSIONS: During the course of this study, the incidence of penicillin resistance inS pneumoniaedoubled. As a result of this increase, infections due to this organism in sites where poor penetration of beta-lactam antibiotics occur may become increasingly difficult to manage.

METHODICAL ASPECTS OF ANTIMICROBIAL SUSCEPTIBILITY TESTING OF SALMONELLA (REVIEW OF LITERATURE)

2019 ◽  
Vol 64 (6) ◽  
pp. 368-375
Author(s):  
S. A. Egorova ◽  
L. A. Kaftyreva
Keyword(s):  
Antimicrobial Susceptibility ◽  
Antimicrobial Therapy ◽  
Susceptibility Testing ◽  
Current Data ◽  
Antimicrobial Susceptibility Testing ◽  
Beta Lactam ◽  
Beta Lactams ◽  
Mechanisms Of Resistance ◽  
Clinically Significant ◽  
Result Interpretation

Salmonella is one of the leading food-borne infection pathogen: annually in the Russian Federation about 50 thousand cases of salmonellosis are registered. Antimicrobial therapy is necessary in the case of severe infection in children under 6 years and persons over 50 years, in patients with severe accompanying disease, as well as in the case of generalization of the infection. Beta-lactam antibiotics, quinolones and azithromycin are included in the list of drugs recommended for antimicrobial therapy of salmonellosis, including typhoid fever. The effectiveness of therapy largely depends on the appropriate antimicrobial susceptibility testing: the choice of testing method, indicator antibiotics and result interpretation. Salmonella belong to the Enterobacteriacae family and are characterized by common mechanisms of resistance to quinolones and beta-lactams, but antimicrobial susceptibility testing of Salmonella to these groups of antibiotics has a number of features. The article presents current data on the susceptibility of Salmonella, including S. Typhi, to antibiotics and leading clinically significant resistance mechanisms. The methodical aspects of Salmonella antimicrobial susceptibility testing of the drugs used for the treatment of salmonellosis (quinolones, beta-lactams and azithromycin) are described in detail. Interpretation of Salmonella testing results according the modern international and Russian recommendations are presented. The authors propose the algorithms for Salmonella antimicrobial susceptibility testing of quinolones, cephalosporins and carbapenems, as well as criteria for result interpretation, allowing the detection of clinically significant mechanisms of resistance to beta-lactams (production of beta-lactamases of different molecular classes) and quinolones (chromosomal mutations and acquired resistance genes).

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