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Pumbwe L, Skilbeck CA, Wexler HM. Impact of anatomic site on growth, efflux-pump expression, cell structure, and stress responsiveness of Bacteroides fragilis. Curr Microbiol 2007; 55:362-5. [PMID: 17882508 DOI: 10.1007/s00284-007-0278-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Accepted: 05/16/2007] [Indexed: 10/22/2022]
Abstract
This study investigated whether B. fragilis from various human sites acquired stable traits enabling it to express certain efflux pumps (EPs), adopt a particular cell structure, and tolerate certain stressors. Isolates from blood, abscess, and stool (n = 11 each) were investigated. Bacteria from various sites portrayed different ultrastructres and EP expression. Blood isolates were tolerant to nutrient limitation and stool isolates to NaCl and bile salt stress. Stressors significantly increased EP expression. These data demonstrate that (1) B. fragilis acquires stable traits from various in vivo microenvironments; (2) that EPs are involved in stress responsiveness; and (3) that EP expression is tightly controlled and site dependent.
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Affiliation(s)
- Lilian Pumbwe
- Greater Los Angeles Veterans Administration Healthcare Systems, University of California, Los Angeles, CA, USA.
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2
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Fang H, Hedberg M, Edlund C, Jarstrand C, Fodor E, Nord CE. Characterization of beta-lactam-resistant Bacteroides fragilis isolates by use of PCR fingerprinting. Anaerobe 2007; 5:11-8. [PMID: 16887657 DOI: 10.1006/anae.1999.0183] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/1998] [Accepted: 02/08/1999] [Indexed: 11/22/2022]
Abstract
PCR fingerprinting was used for characterization of 35 beta-lactam-resistant Bacteroides fragilis strains isolated in Sweden and Hungary. Ten B. fragilis strains showed unique PCR fingerprints by use of the M13 core primer. Their main product was a DNA fragment with a length of 2000-bp which was absent in the other 25 strains and the reference strain B. fragilis ATCC 25285. The 2000-bp fragment from four imipenem-resistant strains gave rise to positive reactions in a specific PCR for detection of ccrA. Printed by the T3B primer, five B. fragilis strains, including the imipenem-resistant strains showed unique PCR fingerprints. The investigated imipenem-resistant strains produced carbapenem-hydrolysing metallo-beta-lactamases. The study indicates that the unique PCR fingerprinting profiles shown in highly beta-lactam resistant B. fragilis strains are correlated to antimicrobial resistance. The PCR fingerprinting technique is a useful tool for differentiation of Bacteroides fragilis strains with high-level beta-lactam resistance.
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Affiliation(s)
- H Fang
- Department of Immunology, Microbiology, Pathology and Infectious Diseases, Karolinska Institute, Huddinge University Hospital, S-141 86, Huddinge, Sweden
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3
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Pumbwe L, Skilbeck CA, Nakano V, Avila-Campos MJ, Piazza RMF, Wexler HM. Bile salts enhance bacterial co-aggregation, bacterial-intestinal epithelial cell adhesion, biofilm formation and antimicrobial resistance of Bacteroides fragilis. Microb Pathog 2007; 43:78-87. [PMID: 17524609 DOI: 10.1016/j.micpath.2007.04.002] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/12/2007] [Indexed: 12/20/2022]
Abstract
Bacteroides fragilis is the most common anaerobic bacterium isolated from human intestinal tract infections. Before B. fragilis interacts with the intestinal epithelial cells, it is exposed to bile salts at physiological concentrations of 0.1-1.3%. The aim of this study was to determine how pre-treatment with bile salts affected B. fragilis cells and their interaction with intestinal epithelial cells. B. fragilis NCTC9343 was treated with conjugated bile salts (BSC) or non-conjugated bile salts (BSM). Cellular ultrastructure was assessed by electron microscopy, gene expression was quantified by comparative quantitative real-time RT-PCR. Adhesion to the HT-29 human intestinal cell line and to PVC microtitre plates (biofilm formation) was determined. Exposure to 0.15% BSC or BSM resulted in overproduction of fimbria-like appendages and outer membrane vesicles, and increased expression of genes encoding RND-type efflux pumps and the major outer membrane protein, OmpA. Bile salt-treated bacteria had increased resistance to structurally unrelated antimicrobial agents and showed a significant increase in bacterial co-aggregation, adhesion to intestinal epithelial cells and biofilm formation. These data suggest that bile salts could enhance intestinal colonization by B. fragilis via several mechanisms, and could therefore be significant to host-pathogen interactions.
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Affiliation(s)
- Lilian Pumbwe
- Greater Los Angeles Veterans Administration Healthcare Systems, CA, USA.
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4
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Fille M, Mango M, Lechner M, Schaumann R. Bacteroides fragilis Group: Trends in Resistance. Curr Microbiol 2006; 52:153-7. [PMID: 16450067 DOI: 10.1007/s00284-005-0249-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2005] [Accepted: 09/20/2005] [Indexed: 10/25/2022]
Abstract
Representing the major part of the human colon microflora, members of the Bacteroides fragilis group are frequently involved in mixed aerobic and anaerobic infections. Recent studies show an increased resistance of the B. fragilis group against several antimicrobial agents. The aim of the present study was to determine the susceptibility of 87 B. fragilis group strains isolated in 2003/2004 in Western Austria against eight antimicrobial agents by Etest. Furthermore, the resistance patterns were compared with those of 45 B. fragilis group strains isolated in 1992 and referred to the world wide trend towards increased resistance. In 1992 as well as in 2003/2004, all strains were susceptible against metronidazole and imipenem. However, comparing the MIC-values of the B. fragilis group strains collected 1992 with data from 2003/2004, a significant increase in resistance was found for clindamycin (p<0.01). Regarding cefoxitin, a similar trend could be observed. However, this difference was not yet significant (p=0.144). Our findings underline the emerging resistance of the B. fragilis group against antimicrobial agents and underscore the importance of susceptibility testing of anaerobes even in routine laboratories.
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Affiliation(s)
- Manfred Fille
- Department of Hygiene, Microbiology and Social Medicine, Division of Hygiene and Medical Microbiology, Innsbruck Medical University, Innsbruck, Austria.
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5
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Spízek J, Rezanka T. Lincomycin, clindamycin and their applications. Appl Microbiol Biotechnol 2004; 64:455-64. [PMID: 14762701 DOI: 10.1007/s00253-003-1545-7] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2003] [Revised: 12/09/2003] [Accepted: 12/15/2003] [Indexed: 02/03/2023]
Abstract
Lincomycin and clindamycin are lincosamide antibiotics used in clinical practice. Both antibiotics are bacteriostatic and inhibit protein synthesis in sensitive bacteria. They may even be bactericidal at the higher concentrations that can be reached in vivo. Clindamycin is usually more active than lincomycin in the treatment of bacterial infections, in particular those caused by anaerobic species; and it can also be used for the treatment of important protozoal diseases, e.g. malaria, most effectively in combination with primaquine. Resistance to lincomycin and clindamycin may be caused by methylation of 23S ribosomal RNA, modification of the antibiotics by specific enzymes or active efflux from the periplasmic space.
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Affiliation(s)
- J Spízek
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídenská 1083, 142 20 Prague, Czech Republic.
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6
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Spízek J, Novotná J, Rezanka T. Lincosamides: Chemical Structure, Biosynthesis, Mechanism of Action, Resistance, and Applications. ADVANCES IN APPLIED MICROBIOLOGY 2004; 56:121-54. [PMID: 15566978 DOI: 10.1016/s0065-2164(04)56004-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Jaroslav Spízek
- Institute of Microbiology Academy of Sciences of the Czech Republic 142 20 Prague 4, Czech Republic.
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7
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Avelar KES, Otsuki K, Vicente ACP, Vieira JMBD, de Paula GR, Domingues RMCP, Ferreira MCDS. Presence of the cfxA gene in Bacteroides distasonis. Res Microbiol 2003; 154:369-74. [PMID: 12837513 DOI: 10.1016/s0923-2508(03)00093-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In this study we investigated the presence of the cfxA gene (encoding a class A beta-lactamase) in 73 strains of the Bacteroides fragilis group belonging to the species B. distasonis (34), B. vulgatus (14), B. thetaiotaomicron (8), B. merdae (6), B. caccae (9) and B. ovatus (2) isolated from human intestinal microflora of healthy children and adults. Employing specific primers to the cfxA gene, a 312-bp amplified fragment was obtained in 2 strains of B. vulgatus and 9 strains, the majority from children, of B. distasonis. The expression of this enzyme was analysed by determining the MICs to cefoxitin and cefotaxime and values varied from 2 to >256 microg/ml of both cefoxitin and cefotaxime. Sequence analysis of the amplicons corresponding to the cfxA gene from B. distasonis and B. vulgatus revealed identical sequences between these isolates and high similarity with other beta-lactamase genes of anaerobes such as cfxA of B. vulgatus (99%) and cfxA2 of Prevotella intermedia (99%), both sequences of which deposited in Genbank under accession numbers U38243 and AF118110, respectively. However, a fragment obtained from a B. distasonis strain (EC17-4) showed a unique RFLP profile and 87% nucleotide similarity with cfxA and cfxA2 genes. These results seem to suggest a dissemination of these resistance determinants among Bacteroides species.
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Affiliation(s)
- Kátia Eliane Santos Avelar
- Instituto de Microbiologia Prof. Paulo de Góes, CCS, Bloco I, UFRJ Universidade Federal do Rio de Janeiro, Ilha do Fundão, RJ, CEP: 21941-590, Rio de Janeiro, Brazil
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8
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Fang H, Edlund C, Hedberg M, Nord CE. New findings in beta-lactam and metronidazole resistant Bacteroides fragilis group. Int J Antimicrob Agents 2002; 19:361-70. [PMID: 12007843 DOI: 10.1016/s0924-8579(02)00019-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Beta-lactam antibiotics and 5-nitroimidazoles have been extensively used against anaerobic bacteria. However, antibiotic resistance is increasingly common among anaerobic Gram-negative bacilli. The classical mechanisms of resistance to beta-lactams are, (1) production of beta-lactamases; (2) alteration of penicillin-binding proteins (PBPs); and (3) changes in outer membrane permeability to beta-lactams. The 5-nitroimidazole molecule is a prodrug whose activation depends upon reduction of the nitro group in the absence of oxygen. Decreased uptake and altered reduction are believed to be responsible for metronidazole resistance. Five nim genes (A, B, C, D and E) have been identified in Bacteroides fragilis group spp. that confer resistance to 5-nitroimidazole antibiotics. Knowledge of the status and the mechanisms of resistance is critical for both the selection of antimicrobial therapy and the design of new antimicrobial agents. The purpose of this article is to review the mechanisms for and the prevalence of beta-lactam and metronidazole resistance in strains belonging to the B. fragilis group.
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Affiliation(s)
- Hong Fang
- Department of Microbiology, Pathology and Immunology, Karolinska Institute, Huddinge University Hospital, SE-141 86, Stockholm, Sweden.
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9
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Betriu C, Sánchez A, Palau ML, Gómez M, Picazo JJ. In vitro activities of MK-0826 and 16 other antimicrobials against Bacteroides fragilis group strains. Antimicrob Agents Chemother 2001; 45:2372-4. [PMID: 11451700 PMCID: PMC90657 DOI: 10.1128/aac.45.8.2372-2374.2001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The activity of MK-0826, a new carbapenem, against 309 Bacteroides fragilis group strains was investigated and compared with that of 11 other beta-lactam and 5 non-beta-lactam agents. MK-0826 showed excellent activity (MICs ranged from < or =0.06 to 4 microg/ml). The new carbapenem may be useful in the treatment of mixed anaerobic infections involving B. fragilis group strains.
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Affiliation(s)
- C Betriu
- Department of Clinical Microbiology, Hospital Clínico San Carlos, 28040 Madrid, Spain.
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10
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Abstract
The first very effective bactericidal anti-anaerobic drug was metronidazole, introduced in clinical practice in the early 1980s. Sometimes penicillin G and chloramphenicol were used successfully in some anaerobic infections. However, this result was most likely due to Gram-positive anaerobic infections (e.g., Clostridium perfringens). Very rapidly, the anti-anaerobic armamentarium was extended with clindamycin, cefoxitin, imipenem and co-amoxyclav or piperacillin-tazobactam. The resistance rate to metronidazole and imipenem remains low but clindamycin has seen an importance decrease in bacterial susceptibility. New additional drugs could be very helpful to overcome resistance and adverse events. The novelties in this field are fluoroquinolones, which exhibit a good activity against Gram-positive cocci and anaerobes.
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Affiliation(s)
- A Bryskier
- Aventis Pharma, Infectious Disease Group, Clinical Pharmacology, 102, Route de Noisy, 93235, Romainville, Cedex, France.
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11
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das Graças Silva E Souza W, Avelar KE, Antunes LC, Lobo LA, Domingues RM, de Souza Ferreira MC. Resistance profile of Bacteroides fragilis isolated in Brazil. Do they shelter the cfiA gene? J Antimicrob Chemother 2000; 45:475-81. [PMID: 10747824 DOI: 10.1093/jac/45.4.475] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The epidemiology of antimicrobial resistance of clinical isolates and human intestinal strains of Bacteroides fragilis has assumed great importance in the last few years since this microorganism, like other members of the B. fragilis group, can be responsible for the spread of resistance determinants. It is possible that the presence of B. fragilis in polluted aquatic environments might contribute to the spread of resistance. The antimicrobial resistance profile of 44 clinical B. fragilis strains isolated from 1981-1988 and 1991-1998 from the University hospital of Rio de Janeiro, and of 17 faecal and 17 polluted aquatic environmental B. fragilis strains isolated between 1991 and 1998 was determined. The susceptibility tests against penicillin, cefoxitin, imipenem, meropenem, clindamycin, chloramphenicol and metronidazole were performed by Etest in Wilkins-Chalgren agar enriched with 5% sheep blood. Motivated by some high MIC values for cefoxitin and meropenem, the cfiA gene, which codes for a metallo-beta-lactamase, was investigated among all strains, using PCR amplification. The resistance to penicillin was high in the samples from 1981 to 1988 (92.9%) and also in those from 1991 to 1998 (100%), although the MIC90 decreased from 256 mg/L to 24 mg/L. An increase in the resistance level to clindamycin and cefoxitin was seen from one decade to the other, the MIC90 values changing from 4 mg/L to 12 mg/L and from 8 mg/L to 32 mg/L, respectively. The susceptibility profile for metronidazole, chloramphenicol, imipenem and meropenem remained stable, although two clinical strains showed MICs of 6 mg/L and 8 mg/L against meropenem. Almost all human intestinal strains were resistant to penicillin and all of them were susceptible to imipenem, meropenem, chloramphenicol and metronidazole. The MICs of meropenem against two strains isolated from a polluted aquatic environment were 6 mg/L and 32 mg/L. The cfiA gene was detected in five strains, two of which were isolated from clinical specimens against which the MIC values of cefoxitin were high and three from an aquatic environment, whose susceptibility to both cefoxitin and meropenem ranged from sensitive to resistant.
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Affiliation(s)
- W das Graças Silva E Souza
- Departamento de Microbiologia Médica, Instituto de Microbiologia Prof. Paulo de Góes, Universidade Federal do Rio de Janeiro, Brazil
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12
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Fang H, Edlund C, Zhang G, Hedberg M. Detection of imipenem-resistant and metronidazole-resistant Bacteroides fragilis group strains in fecal samples. Clin Microbiol Infect 1999. [DOI: 10.1111/j.1469-0691.1999.tb00709.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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13
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Labbé AC, Bourgault AM, Vincelette J, Turgeon PL, Lamothe F. Trends in antimicrobial resistance among clinical isolates of the Bacteroides fragilis group from 1992 to 1997 in Montreal, Canada. Antimicrob Agents Chemother 1999; 43:2517-9. [PMID: 10508035 PMCID: PMC89511 DOI: 10.1128/aac.43.10.2517] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The objective of the present study was to analyze the susceptibility profiles of 911 clinical strains of the Bacteroides fragilis group isolated from 1992 to 1997 in our institution in order to monitor susceptibility changes over time. Whereas the rates of resistance to metronidazole, imipenem, piperacillin-tazobactam, ticarcillin-clavulanic acid, penicillin, piperacillin, and cefoxitin remained essentially unchanged, there was a significant increase in the rates of resistance to clindamycin, which rose from 8.2% in 1992 to 19.7% in 1997 (P < 0.0004).
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Affiliation(s)
- A C Labbé
- Département de Microbiologie Médicale et Infectiologie, Centre Hospitalier de l'Université de Montréal, Montréal, Canada
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Betriu C, Gómez M, Palau ML, Sánchez A, Picazo JJ. Activities of new antimicrobial agents (trovafloxacin, moxifloxacin, sanfetrinem, and quinupristin-dalfopristin) against Bacteroides fragilis group: comparison with the activities of 14 other agents. Antimicrob Agents Chemother 1999; 43:2320-2. [PMID: 10471590 PMCID: PMC89472 DOI: 10.1128/aac.43.9.2320] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The antimicrobial activities of trovafloxacin, moxifloxacin, sanfetrinem, quinupristin-dalfopristin, and 14 other antimicrobial agents against 218 Bacteroides fragilis group strains were determined. A group of 10 imipenem-resistant strains were also tested. Imipenem, meropenem, and sanfetrinem had the lowest MICs of all of the beta-lactams. Quinupristin-dalfopristin inhibited all of the strains at 2 microg/ml. Overall, the MICs of trovafloxacin and moxifloxacin for 90% of the strains tested were 1 and 2 microg/ml, respectively.
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Affiliation(s)
- C Betriu
- Servicio de Microbiología Clínica, Hospital Clínico San Carlos, 28040 Madrid, Spain.
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15
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Comparison of the Activity of Meropenem and Imipenem Against Anaerobic Bacteria in Bulgaria. Anaerobe 1999. [DOI: 10.1006/anae.1999.0258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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16
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Abstract
With a few notable exceptions, most antibiotics can be used with relative safety during pregnancy. Moreover, none of the antibiotics to date has been shown to be teratogenic, although tetracycline may cause yellow-brown discoloration of the deciduous teeth (a fetal effect). Thus, antibiotics should not be withheld from the pregnant woman, especially when indicated for serious, life-threatening infections.
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Affiliation(s)
- J S Dashe
- Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, USA
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17
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Bianchini H, Canigia LF, Predari SC, Rollet R, Litterio M, Berestein P, Castello L, De Martino A, Greco G, Hardie N. Broth disk elution method for anaerobic bacteria: a collaborative study to assess its reliability for clinical purposes. Anaerobe 1997; 3:225-31. [PMID: 16887595 DOI: 10.1006/anae.1997.0110] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/1996] [Accepted: 06/09/1997] [Indexed: 11/22/2022]
Abstract
A collaborative study involving seven laboratories was undertaken to evaluate the reproducibility and the reliability of the broth disk elution test against anaerobic bacteria by comparing with the reference agar dilution method. A two breakpoint broth test was also evaluated. Assays were performed using the same testing conditions (i.e. medium, temperature, atmosphere and incubation time). One hundred Gram-negative and Gram-positive clinical isolates were initially studied. Overall agreement of 98.5% and 97.5%, were found for disk elution and the two breakpoint tests, respectively. In order to assess the reliability of the disk elution test, two different lots (LOT1 and LOT2) of disks of piperacillin and clindamycin were selected, to obtain two final concentrations after dilution (10 and 60 mg/mL; 1 and 4 mg/mL, respectively). Two hundred and eighty assays were performed against one strain of both Bacteroides fragilis(piperacillin MIC, 8.0 mg/mL; clindamycin MIC, <0.5 mg/mL) and Bacteroides thetaiotaomicron(piperacillin MIC, 16.0 mg/mL; clindamycin MIC, <0.5 mg/mL). With LOT 1, considering both species and both antibiotics, the agreement among six laboratories ranged from 85% to 100% (P > 0.05) with the higher concentration. Overall agreement among all laboratories was 91%. No optimal agreement (>90%) for clindamycin-Bacteroides thetaiotaomicron using the LOT1 (77%) was found. Since this finding was not observed with LOT2 (100% agreement), discrepancies were attributed to variation between lots. Overall agreement with LOT2 was 100% for all centres. The present study indicates that the broth disk elution method proved to be a reliable and suitable alternative for routine susceptibility testing for anaerobic bacteria, as a resistance screening method for clinical purposes.
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Affiliation(s)
- H Bianchini
- Department of Clinical Analyses, Laboratory of Microbiology, Centre of Medical Education and Clinical Research (CEMIC), Billingshurst 2447, (1425), Buenos Aires, Argentina
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18
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de Carvalho CB, Moreira JL, Ferreira MC. Epidemiology and antimicrobial resistance of B. fragilis group organisms isolated from clinical specimen and human intestinal microbiota. Rev Inst Med Trop Sao Paulo 1996; 38:329-35. [PMID: 9293074 DOI: 10.1590/s0036-46651996000500003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Epidemiological aspects and the antimicrobial susceptibility profile of the Bacteroides fragilis group isolated from clinical and human intestinal specimens were examined in this study. B. fragilis group strains were isolated from 46 (37%) of 124 clinical specimens and the source of the samples was: Blood culture (3), intraabdominal infection (27), brain abscess (2), soft tissue infection (17), respiratory sinus (3), pleural aspirate (9), breast abscess (3), surgical infected wound (22), pelvic inflammatory disease (22), chronic otitis media (9) and miscellaneous (7). Intraabdominal and soft tissue infections were responsible for more than half of the clinical isolates. Susceptibility to penicillin, cefoxitin, tetracycline, metronidazole, chloramphenicol and clindamycin was examined. All isolates were susceptible to metronidazole and chloramphenicol. For clindamycin and cefoxitin the resistance rates observed were 21.7% and 10.9% respectively. Susceptibility profiles varied among the different species tested. A total of 37 species of B. fragilis group isolated from intestinal microbiota of individuals who had no antimicrobial therapy for at least 1 month before the sampling was also examined. All strains were also susceptible to chloramphenicol and metronidazole and the resistance rates to clindamycin and cefoxitin were 19.4% and 5.4% respectively. A few institutions, in Brazil, have monitored the antimicrobial susceptibility of B. fragilis group strains isolated from anaerobic infections. The resistance rates to cefoxitin and clindamycin and the variation in susceptibility patterns among the species isolated in this study emphasize the need for monitoring of susceptibility patterns of B. fragilis group organisms isolated, especially at our University Hospitals.
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Affiliation(s)
- C B de Carvalho
- Laboratório de Microbiologia Médica, Hospital Universitário Walter Cantídio, Universidade Federal do Ceurá, Brasil
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19
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Balfour JA, Bryson HM, Brogden RN. Imipenem/cilastatin: an update of its antibacterial activity, pharmacokinetics and therapeutic efficacy in the treatment of serious infections. Drugs 1996; 51:99-136. [PMID: 8741235 DOI: 10.2165/00003495-199651010-00008] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The prototype carbapenem antibacterial agent imipenem has a very broad spectrum of antibacterial activity, encompassing most Gram-negative and Gram-positive aerobes and anaerobes, including most beta-lactamase-producing species. It is coadministered with a renal dehydropeptidase inhibitor, cilastatin, in order to prevent its renal metabolism in clinical use. Extensive clinical experience gained with imipenem/cilastatin has shown it to provide effective monotherapy for septicaemia, neutropenic fever, and intra-abdominal, lower respiratory tract, genitourinary, gynaecological, skin and soft tissues, and bone and joint infections. In these indications, imipenem/cilastatin generally exhibits similar efficacy to broad-spectrum cephalosporins and other carbapenems and is at least equivalent to standard aminoglycoside-based and other combination regimens. Imipenem/cilastatin is generally well tolerated by adults and children, with local injection site events, gastrointestinal disturbances and dermatological reactions being the most common adverse events. Seizures have also been reported, occurring mostly in patients with impaired renal function or CNS pathology, or with excessive dosage. Although it is no longer a unique compound, as newer carbapenems such as meropenem are becoming available, imipenem/cilastatin nevertheless remains an important agent with established efficacy as monotherapy for moderate to severe bacterial infections. Its particular niche is in treating infections known or suspected to be caused by multiresistant pathogens.
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Affiliation(s)
- J A Balfour
- Adis International Limited, Auckland, New Zealand
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20
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Abstract
Because of the large number of cephalosporins available for use, and for economic reasons, most hospitals have restricted the number of cephalosporins for inclusion on hospital formularies. No more than one first-generation oral and parenteral cephalosporin is necessary. The second- and third-generation oral cephalosporins are more active in vitro against Haemophilus influenzae and Enterobacteriaceae, and the selection of one of these drugs should be based primarily on acquisition cost. There is usually minimal, if any, need for a second-generation parenteral cephalosporin on hospital formularies. The choice of a single third-generation parenteral cephalosporin should be made primarily on the cost of equivalent daily dosages. A single antipseudomonal cephalosporin should be included in the hospital formulary, and the selection should be based on cost and availability.
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Affiliation(s)
- W R Wilson
- Mayo Medical School, Mayo Clinic, Rochester, MN, USA
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