- Email: [email protected]
Re: Acute bacterial prostatitis in Korea
Letters to the Editor / International Journal of Antimicrobial Agents 34 (2009) 181–195
185
Re: Acute bacterial prostatitis in Korea Sir,
Fig. 1. Observed biapenem concentrations in plasma and cerebrospinal fluid (CSF) after a 1-h infusion of 300 mg biapenem, and simulation curves using the mean fixed-effects parameters. S.D., standard deviation.
MIC of the causative pathogen is determined for each patient, the CSF pharmacodynamic-derived breakpoints should help to choose a more appropriate BIPM regimen based on the MIC value. The clinical implications of these findings need to be confirmed in a larger number of patients with various characteristics. Funding: No funding sources. Competing interests: None declared. Ethical approval: Ethics Committee of Hiroshima Prefectural Hospital, Hiroshima, Japan. References [1] Ikawa K, Morikawa N, Ikeda K, Tsumura R, Shibukawa M, Iida K, et al. Considerations of meropenem dosage for bacterial meningitis based on pharmacodynamics in cerebrospinal fluid. Int J Antimicrob Agents 2008;32:96–8. [2] Zhanel GG, Wiebe R, Dilay L, Thomson K, Rubinstein E, Hoban DJ, et al. Comparative review of the carbapenems. Drugs 2007;67:1027–52. [3] Ikeda K, Ikawa K, Ikeda A, Nishikawa Y, Morikawa N. A simple and rapid determination of biapenem in plasma by high-performance liquid chromatography. J Chromatogr B Anal Technol Biomed Life Sci 2006;844:148–52. [4] Lutsar I, McCracken Jr GH, Friedland IR. Antibiotic pharmacodynamics in cerebrospinal fluid. Clin Infect Dis 1998;27:1117–27. [5] Gilbert DN, Moellering RC, Ellopoulos GM, Sande MA, editors. The Sanford guide to antimicrobial therapy. Sperryville, VA: Antimicrobial Therapy Inc.; 2007. p. 22. [6] Yamaguchi K, Ishii Y, Iwata M, Watanabe N, Uehara N, Yasujima M, et al. Nationwide surveillance of parenteral antibiotics containing meropenem activities against clinically isolated strains in 2006 [in Japanese]. Jpn J Antibiot 2007;60:344–77. [7] Ikawa K, Morikawa N, Ikeda K, Ohge H, Sueda T, Suyama H, et al. Pharmacokinetic–pharmacodynamic target attainment analysis of biapenem in adult patients: a dosing strategy. Chemotherapy 2008;54:386–94.
Kazuro Ikawa a,∗ Norifumi Morikawa a Kayo Ikeda a Masaya Katagiri b Katsuzo Kiya b Naoyuki Isobe b Tatsuya Mizoue b Hiroshi Kondo b Motoki Takano b a Department of Clinical Pharmacotherapy, Hiroshima University, 1–2–3 Kasumi, Minami-ku, Hiroshima 734–8551, Japan b Department of Neurosurgery, Hiroshima Prefectural Hospital, 1–5–54 Ujinakanda, Minami-ku, Hiroshima 734–8530, Japan ∗ Corresponding
author. Tel.: +81 82 257 5296; fax: +81 82 257 5320. E-mail address: [email protected] (K. Ikawa)
doi:10.1016/j.ijantimicag.2009.02.001
29 January 2009
We read with great interest the article by Ha et al. [1] regarding the features and outcome of acute bacterial prostatitis (ABP) in a series of 473 inpatients from different Korean urological centres. We have some comments and questions about their results. Ha et al. showed that ABP with prior manipulation of the lower urinary tract was more severe in terms of microbiological features (more resistant pathogens), clinical symptoms (more fever and urinary complaints) and outcome (more abscesses and trend to more recurrence or progression to chronic prostatitis). As previously reported [2], we have also observed that healthcare-related ABP was more severe in terms of resistant pathogens (Enterococcus, Pseudomonas aeruginosa, meticillin-resistant Staphylococcus aureus, multidrug-resistant Escherichia coli etc.) and bacteriological failure. However, in our series we observed a trend to less fever, less chills and less urinary symptoms in healthcare-related ABP (Table 1) [3]. The reason for such a discrepancy is unclear. Our results were obtained in a series of inpatients, among whom one-half (193/371; 52%) were admitted in medical wards and the rate of healthcare-related ABP was similar in urology and medicine (21% vs. 20%). According to the current French recommendations, our definition of healthcare-related ABP included not only infections following manipulation [Foley catheter (35/76; 46%) and prostatic biopsy (19/76; 25%)] but also ABP acquired >48 h after admission. We did not notice more severe symptoms among the group of patients with prior manipulation of the lower urinary tract (data not shown). In their series of urological patients, Ha et al. reported a high rate of post-manipulation ABP that occurred after a prostatic biopsy (57/130; 44%). This feature raises the question of the prophylactic measures used before prostatic biopsy in the different Korean participating centres. The authors stated that the
Table 1 Symptoms, microbiological data and outcome of acute bacterial prostatitis in a series of 371 French inpatients.
Symptoms Fever Chills Urinary symptoms
Not healthcare-related (n = 295)
Healthcare-related (n = 76)
P-value
250/295 (85%) 108/295 (37%) 229/295 (78%)
47/76 (62%) 20/76 (26%) 37/76 (49%)
<0.01 0.1 <0.01
15 (26%) 5 (9%) 6 (11%) 8 (14%) 12 (21%)
<0.01 0.5 0.8 0.02 <0.01
Strains isolated in urine (n = 270) Escherichia coli 142 (67%) Proteus spp. 11 (5%) 18 (8%) KES groupa Enterococcus spp. 8 (4%) Pseudomonas 8 (4%) aeruginosa Staphylococcus 3 (1%) aureus Other 23 (11%)
5 (9%) 6 (11%)
0.02 >0.9
E. coli susceptibility (n = 157)b Amoxicillin AMC Ofloxacin SXT
142
15
88 (62%) 93 (65%) 120 (85%) 115 (81%)
7 (47%) 11 (73%) 10 (67%) 7 (47%)
0.4 0.7 0.2 <0.01
Bacterial failure at follow-up
23/124 (19%)
14/29 (48%)
<0.01
AMC, amoxicillin/clavulanic acid; SXT, trimethoprim/sulfamethoxazole. a Klebsiella, Enterobacter, Serratia. b Following the French technical recommendations for in vitro susceptibility testing [3].
186
Letters to the Editor / International Journal of Antimicrobial Agents 34 (2009) 181–195
current guidelines from the European Association of Urology [4] were in use in many Korean urology centres for antibiotic curative treatment. What about the guidelines in use for the antibiotic prophylaxis of prostatic biopsy? Of note, there are some major variations in the recommendations from one country to another: some current guidelines recommend a fluoroquinolone [5,6], whilst others recommend to choose between a fluoroquinolone, trimethoprim/sulfamethoxazole and even metronidazole [4]. Some of these regimens now seem inappropriate, at least in countries with high resistance rates. For instance, the pertinence of fluoroquinolones as prophylactic agents in Korean urological centres seems questionable because of the very low rate of ciprofloxacin susceptibility described by Ha et al. in pathogens isolated from ABP with prior manipulation (53%). However, the gap in the susceptibility rates between ciprofloxacin and ofloxacin (53.3% vs. 91.5%; Table 4 in [1]) for the same pathogens is highly confusing. For their total series (ABP with or without prior manipulation), Ha et al. related a surprising excess of ciprofloxacin resistance compared with ofloxacin, both against E. coli (76.2% of strains susceptible to ciprofloxacin vs. 94.1% to ofloxacin) and against other pathogens (68.4% vs. 77.8%). This contrasts with the well-known cross-resistance between ciprofloxacin and ofloxacin, with a usual slight advantage of ciprofloxacin in terms of minimum inhibitory concentration (MIC) values for Gram-negative pathogens [7]. Thus, we believe that the authors should give more details and references on the methods used for the microbiological susceptibility testing below the statement that tests have been performed “according the guidelines of the National Committee for Clinical Laboratory Standards” (now the Clinical and Laboratory Standards Institute). Because of their high severity, post-biopsy and any other healthcare-related ABP should first be prevented. Antibiotic prophylaxis and treatment regimens should be targeted according to local reliable epidemiological data. Funding: No funding sources. Competing interests: None declared. Ethical approval: Not required.
References [1] Ha US, Kim ME, Kim CS, Shim BS, Han CH, Lee SD, et al. Acute bacterial prostatitis in Korea: clinical outcome, including symptoms, management, microbiology and course of disease. Int J Antimicrob Agents 2008;31(Suppl. 1):S96–101. [2] Etienne M, Chavanet P, Sibert L, Michel F, Levesque H, Lorcerie B, et al. Acute bacterial prostatitis: heterogeneity in diagnostic criteria and management. Retrospective multicentric analysis of 371 patients diagnosed with acute prostatitis. BMC Infect Dis 2008;8:12. [3] Comité de l’Antibiogramme de la Société Franc¸aise de Microbiologie. 1996 report of the Comité de l’Antibiogramme de la Société Franc¸aise de Microbiologie. Technical recommendations for in vitro susceptibility testing. Clin Microbiol Infect 1996;2S1:11–25. [4] Naber KG, Bjerklund-Johansen TE, Botto H, Grabe M, Lobel B, Palou J, et al. Guidelines on the management of urinary and male genital tract infections (2006 update). Arnhem, The Netherlands: European Association of Urology; 2006. [5] Société Francaise d’Anesthésie et de Réanimation. Recommandations pour la pratique de l’antibioprohylaxie en chirurgie-actualisation 1999. Ann Fr Anesth Reanim 1999;124:441–7. [6] Matsumoto T, Kiyota H, Matsukawa M, Yasuda M, Arakawa S, Monden K; Japanese Society of UTI Cooperative Study Group. Japanese guidelines for prevention of perioperative infections in urological field. Int J Urol 2007;14:890– 909. [7] Hooper DC. Quinolones. In: Mandell GL, Benett JE, Dolin R, editors. Principles and practice of infectious diseases, 1, 6th rev. ed. Philadelphia, PA: Elsevier, Churchill Livingstone; 2005. p. 451–73.
Manuel Etienne ∗ Franc¸ois Caron Rouen University Hospital, Rouen, France
∗ Corresponding
author. Tel.: +33 2 32 88 81 15; fax: +33 2 32 88 68 09. E-mail address: [email protected] (M. Etienne) doi:10.1016/j.ijantimicag.2009.02.004
Genotypic rpoB and gyrA profiles for detection of rifampicin and fluoroquinolone susceptibilities of Mycobacterium tuberculosis isolates directly from clinical sputum specimens Sir, Drug susceptibility testing (DST) is of paramount importance to diagnosis, infection control and provision of proper guidance for the treatment of multidrug-resistant and extensively drug-resistant tuberculosis (MDR-TB and XDR-TB, respectively). Molecular tests on resistance genes allow rapid detection of drug resistance, especially when they are applied directly to clinical samples. Most rifampicin-resistant Mycobacterium tuberculosis strains contain mutations in an 81 bp region of the rpoB gene, which may be used as a surrogate marker for multidrug-resistant disease. Likewise, fluoroquinolone resistance can depict poor prognostic outcome in MDR-TB patients and connotes XDR-TB [1]. Early detection of fluoroquinolone-resistant MDR-TB facilitates treatment with alternative drugs and/or adjunctive surgery to improve prognosis. Molecular approaches for detecting fluoroquinolone resistance generally involve the gyrA gene [2]. Multiplex polymerase chain reaction (PCR) amplimer conformation (MPAC) analysis allows direct detection of mutations in both rpoB and gyrA [2]. Since this procedure can be completed within 6 h, we conducted a field study to evaluate its applicability in rapid and early delineation of rifampicin and fluoroquinolone susceptibilities of M. tuberculosis directly in sputum. Smear-positive sputum specimens were collected over a period of 12 months. Each specimen was subjected to culture by the MGIT system; recoverable colonies were tested for susceptibilities to rifampicin and levofloxacin. The time of reporting usually took 5–8 weeks. The specimens were also subjected to direct gene probe analysis (Gene Probe Inc.) to determine whether the acid-fast bacilli belonged to M. tuberculosis complex. The specimens were then subjected to cleaning, DNA extraction and purification, followed by MPAC analysis of rpoB and gyrA to depict susceptibility to rifampicin and levofloxacin [2]. The time of reporting was within the next day of report of the smear-positive results. Data obtained from routine DST and molecular investigations were compared for accuracy, rapidity and cost of analysis. A total of 503 sputum specimens were analysed in this study. The cost of performing MPAC analysis for rpoB and gyrA was ca. US$7.0 per specimen. A summary of MPAC analysis and routine DST is presented in Table 1. Of the 503 specimens, 389 (77.3%) were PCR amplifiable for rpoB, of which 341 (87.7%) were amplifiable for gyrA. For rpoB, 25 specimens exhibited mutated patterns, 15 of which contained rifampicin-resistant M. tuberculosis [minimum inhibitory concentration (MIC) > 64 mg/L]. For the remaining 10 specimens, rifampicin susceptibility was not determined owing to recovery of non-tuberculous mycobacteria (NTM). For gyrA, only six specimens exhibited mutational patterns, one of which contained a mixed culture of M. tuberculosis and NTM, hence DST could not be performed. Organisms recovered from the other five specimens were resistant to levofloxacin, with a MIC > 4.8 mg/L. Two of these contained mutations in rpoB and exhibited resistance to rifampicin concomitantly. Three were resistant to levofloxacin but not rifampicin, suggesting that development of fluoroquinolone resistance is not necessarily associated with resistance to rifampicin. This phenomenon might be due to
185
Re: Acute bacterial prostatitis in Korea Sir,
Fig. 1. Observed biapenem concentrations in plasma and cerebrospinal fluid (CSF) after a 1-h infusion of 300 mg biapenem, and simulation curves using the mean fixed-effects parameters. S.D., standard deviation.
MIC of the causative pathogen is determined for each patient, the CSF pharmacodynamic-derived breakpoints should help to choose a more appropriate BIPM regimen based on the MIC value. The clinical implications of these findings need to be confirmed in a larger number of patients with various characteristics. Funding: No funding sources. Competing interests: None declared. Ethical approval: Ethics Committee of Hiroshima Prefectural Hospital, Hiroshima, Japan. References [1] Ikawa K, Morikawa N, Ikeda K, Tsumura R, Shibukawa M, Iida K, et al. Considerations of meropenem dosage for bacterial meningitis based on pharmacodynamics in cerebrospinal fluid. Int J Antimicrob Agents 2008;32:96–8. [2] Zhanel GG, Wiebe R, Dilay L, Thomson K, Rubinstein E, Hoban DJ, et al. Comparative review of the carbapenems. Drugs 2007;67:1027–52. [3] Ikeda K, Ikawa K, Ikeda A, Nishikawa Y, Morikawa N. A simple and rapid determination of biapenem in plasma by high-performance liquid chromatography. J Chromatogr B Anal Technol Biomed Life Sci 2006;844:148–52. [4] Lutsar I, McCracken Jr GH, Friedland IR. Antibiotic pharmacodynamics in cerebrospinal fluid. Clin Infect Dis 1998;27:1117–27. [5] Gilbert DN, Moellering RC, Ellopoulos GM, Sande MA, editors. The Sanford guide to antimicrobial therapy. Sperryville, VA: Antimicrobial Therapy Inc.; 2007. p. 22. [6] Yamaguchi K, Ishii Y, Iwata M, Watanabe N, Uehara N, Yasujima M, et al. Nationwide surveillance of parenteral antibiotics containing meropenem activities against clinically isolated strains in 2006 [in Japanese]. Jpn J Antibiot 2007;60:344–77. [7] Ikawa K, Morikawa N, Ikeda K, Ohge H, Sueda T, Suyama H, et al. Pharmacokinetic–pharmacodynamic target attainment analysis of biapenem in adult patients: a dosing strategy. Chemotherapy 2008;54:386–94.
Kazuro Ikawa a,∗ Norifumi Morikawa a Kayo Ikeda a Masaya Katagiri b Katsuzo Kiya b Naoyuki Isobe b Tatsuya Mizoue b Hiroshi Kondo b Motoki Takano b a Department of Clinical Pharmacotherapy, Hiroshima University, 1–2–3 Kasumi, Minami-ku, Hiroshima 734–8551, Japan b Department of Neurosurgery, Hiroshima Prefectural Hospital, 1–5–54 Ujinakanda, Minami-ku, Hiroshima 734–8530, Japan ∗ Corresponding
author. Tel.: +81 82 257 5296; fax: +81 82 257 5320. E-mail address: [email protected] (K. Ikawa)
doi:10.1016/j.ijantimicag.2009.02.001
29 January 2009
We read with great interest the article by Ha et al. [1] regarding the features and outcome of acute bacterial prostatitis (ABP) in a series of 473 inpatients from different Korean urological centres. We have some comments and questions about their results. Ha et al. showed that ABP with prior manipulation of the lower urinary tract was more severe in terms of microbiological features (more resistant pathogens), clinical symptoms (more fever and urinary complaints) and outcome (more abscesses and trend to more recurrence or progression to chronic prostatitis). As previously reported [2], we have also observed that healthcare-related ABP was more severe in terms of resistant pathogens (Enterococcus, Pseudomonas aeruginosa, meticillin-resistant Staphylococcus aureus, multidrug-resistant Escherichia coli etc.) and bacteriological failure. However, in our series we observed a trend to less fever, less chills and less urinary symptoms in healthcare-related ABP (Table 1) [3]. The reason for such a discrepancy is unclear. Our results were obtained in a series of inpatients, among whom one-half (193/371; 52%) were admitted in medical wards and the rate of healthcare-related ABP was similar in urology and medicine (21% vs. 20%). According to the current French recommendations, our definition of healthcare-related ABP included not only infections following manipulation [Foley catheter (35/76; 46%) and prostatic biopsy (19/76; 25%)] but also ABP acquired >48 h after admission. We did not notice more severe symptoms among the group of patients with prior manipulation of the lower urinary tract (data not shown). In their series of urological patients, Ha et al. reported a high rate of post-manipulation ABP that occurred after a prostatic biopsy (57/130; 44%). This feature raises the question of the prophylactic measures used before prostatic biopsy in the different Korean participating centres. The authors stated that the
Table 1 Symptoms, microbiological data and outcome of acute bacterial prostatitis in a series of 371 French inpatients.
Symptoms Fever Chills Urinary symptoms
Not healthcare-related (n = 295)
Healthcare-related (n = 76)
P-value
250/295 (85%) 108/295 (37%) 229/295 (78%)
47/76 (62%) 20/76 (26%) 37/76 (49%)
<0.01 0.1 <0.01
15 (26%) 5 (9%) 6 (11%) 8 (14%) 12 (21%)
<0.01 0.5 0.8 0.02 <0.01
Strains isolated in urine (n = 270) Escherichia coli 142 (67%) Proteus spp. 11 (5%) 18 (8%) KES groupa Enterococcus spp. 8 (4%) Pseudomonas 8 (4%) aeruginosa Staphylococcus 3 (1%) aureus Other 23 (11%)
5 (9%) 6 (11%)
0.02 >0.9
E. coli susceptibility (n = 157)b Amoxicillin AMC Ofloxacin SXT
142
15
88 (62%) 93 (65%) 120 (85%) 115 (81%)
7 (47%) 11 (73%) 10 (67%) 7 (47%)
0.4 0.7 0.2 <0.01
Bacterial failure at follow-up
23/124 (19%)
14/29 (48%)
<0.01
AMC, amoxicillin/clavulanic acid; SXT, trimethoprim/sulfamethoxazole. a Klebsiella, Enterobacter, Serratia. b Following the French technical recommendations for in vitro susceptibility testing [3].
186
Letters to the Editor / International Journal of Antimicrobial Agents 34 (2009) 181–195
current guidelines from the European Association of Urology [4] were in use in many Korean urology centres for antibiotic curative treatment. What about the guidelines in use for the antibiotic prophylaxis of prostatic biopsy? Of note, there are some major variations in the recommendations from one country to another: some current guidelines recommend a fluoroquinolone [5,6], whilst others recommend to choose between a fluoroquinolone, trimethoprim/sulfamethoxazole and even metronidazole [4]. Some of these regimens now seem inappropriate, at least in countries with high resistance rates. For instance, the pertinence of fluoroquinolones as prophylactic agents in Korean urological centres seems questionable because of the very low rate of ciprofloxacin susceptibility described by Ha et al. in pathogens isolated from ABP with prior manipulation (53%). However, the gap in the susceptibility rates between ciprofloxacin and ofloxacin (53.3% vs. 91.5%; Table 4 in [1]) for the same pathogens is highly confusing. For their total series (ABP with or without prior manipulation), Ha et al. related a surprising excess of ciprofloxacin resistance compared with ofloxacin, both against E. coli (76.2% of strains susceptible to ciprofloxacin vs. 94.1% to ofloxacin) and against other pathogens (68.4% vs. 77.8%). This contrasts with the well-known cross-resistance between ciprofloxacin and ofloxacin, with a usual slight advantage of ciprofloxacin in terms of minimum inhibitory concentration (MIC) values for Gram-negative pathogens [7]. Thus, we believe that the authors should give more details and references on the methods used for the microbiological susceptibility testing below the statement that tests have been performed “according the guidelines of the National Committee for Clinical Laboratory Standards” (now the Clinical and Laboratory Standards Institute). Because of their high severity, post-biopsy and any other healthcare-related ABP should first be prevented. Antibiotic prophylaxis and treatment regimens should be targeted according to local reliable epidemiological data. Funding: No funding sources. Competing interests: None declared. Ethical approval: Not required.
References [1] Ha US, Kim ME, Kim CS, Shim BS, Han CH, Lee SD, et al. Acute bacterial prostatitis in Korea: clinical outcome, including symptoms, management, microbiology and course of disease. Int J Antimicrob Agents 2008;31(Suppl. 1):S96–101. [2] Etienne M, Chavanet P, Sibert L, Michel F, Levesque H, Lorcerie B, et al. Acute bacterial prostatitis: heterogeneity in diagnostic criteria and management. Retrospective multicentric analysis of 371 patients diagnosed with acute prostatitis. BMC Infect Dis 2008;8:12. [3] Comité de l’Antibiogramme de la Société Franc¸aise de Microbiologie. 1996 report of the Comité de l’Antibiogramme de la Société Franc¸aise de Microbiologie. Technical recommendations for in vitro susceptibility testing. Clin Microbiol Infect 1996;2S1:11–25. [4] Naber KG, Bjerklund-Johansen TE, Botto H, Grabe M, Lobel B, Palou J, et al. Guidelines on the management of urinary and male genital tract infections (2006 update). Arnhem, The Netherlands: European Association of Urology; 2006. [5] Société Francaise d’Anesthésie et de Réanimation. Recommandations pour la pratique de l’antibioprohylaxie en chirurgie-actualisation 1999. Ann Fr Anesth Reanim 1999;124:441–7. [6] Matsumoto T, Kiyota H, Matsukawa M, Yasuda M, Arakawa S, Monden K; Japanese Society of UTI Cooperative Study Group. Japanese guidelines for prevention of perioperative infections in urological field. Int J Urol 2007;14:890– 909. [7] Hooper DC. Quinolones. In: Mandell GL, Benett JE, Dolin R, editors. Principles and practice of infectious diseases, 1, 6th rev. ed. Philadelphia, PA: Elsevier, Churchill Livingstone; 2005. p. 451–73.
Manuel Etienne ∗ Franc¸ois Caron Rouen University Hospital, Rouen, France
∗ Corresponding
author. Tel.: +33 2 32 88 81 15; fax: +33 2 32 88 68 09. E-mail address: [email protected] (M. Etienne) doi:10.1016/j.ijantimicag.2009.02.004
Genotypic rpoB and gyrA profiles for detection of rifampicin and fluoroquinolone susceptibilities of Mycobacterium tuberculosis isolates directly from clinical sputum specimens Sir, Drug susceptibility testing (DST) is of paramount importance to diagnosis, infection control and provision of proper guidance for the treatment of multidrug-resistant and extensively drug-resistant tuberculosis (MDR-TB and XDR-TB, respectively). Molecular tests on resistance genes allow rapid detection of drug resistance, especially when they are applied directly to clinical samples. Most rifampicin-resistant Mycobacterium tuberculosis strains contain mutations in an 81 bp region of the rpoB gene, which may be used as a surrogate marker for multidrug-resistant disease. Likewise, fluoroquinolone resistance can depict poor prognostic outcome in MDR-TB patients and connotes XDR-TB [1]. Early detection of fluoroquinolone-resistant MDR-TB facilitates treatment with alternative drugs and/or adjunctive surgery to improve prognosis. Molecular approaches for detecting fluoroquinolone resistance generally involve the gyrA gene [2]. Multiplex polymerase chain reaction (PCR) amplimer conformation (MPAC) analysis allows direct detection of mutations in both rpoB and gyrA [2]. Since this procedure can be completed within 6 h, we conducted a field study to evaluate its applicability in rapid and early delineation of rifampicin and fluoroquinolone susceptibilities of M. tuberculosis directly in sputum. Smear-positive sputum specimens were collected over a period of 12 months. Each specimen was subjected to culture by the MGIT system; recoverable colonies were tested for susceptibilities to rifampicin and levofloxacin. The time of reporting usually took 5–8 weeks. The specimens were also subjected to direct gene probe analysis (Gene Probe Inc.) to determine whether the acid-fast bacilli belonged to M. tuberculosis complex. The specimens were then subjected to cleaning, DNA extraction and purification, followed by MPAC analysis of rpoB and gyrA to depict susceptibility to rifampicin and levofloxacin [2]. The time of reporting was within the next day of report of the smear-positive results. Data obtained from routine DST and molecular investigations were compared for accuracy, rapidity and cost of analysis. A total of 503 sputum specimens were analysed in this study. The cost of performing MPAC analysis for rpoB and gyrA was ca. US$7.0 per specimen. A summary of MPAC analysis and routine DST is presented in Table 1. Of the 503 specimens, 389 (77.3%) were PCR amplifiable for rpoB, of which 341 (87.7%) were amplifiable for gyrA. For rpoB, 25 specimens exhibited mutated patterns, 15 of which contained rifampicin-resistant M. tuberculosis [minimum inhibitory concentration (MIC) > 64 mg/L]. For the remaining 10 specimens, rifampicin susceptibility was not determined owing to recovery of non-tuberculous mycobacteria (NTM). For gyrA, only six specimens exhibited mutational patterns, one of which contained a mixed culture of M. tuberculosis and NTM, hence DST could not be performed. Organisms recovered from the other five specimens were resistant to levofloxacin, with a MIC > 4.8 mg/L. Two of these contained mutations in rpoB and exhibited resistance to rifampicin concomitantly. Three were resistant to levofloxacin but not rifampicin, suggesting that development of fluoroquinolone resistance is not necessarily associated with resistance to rifampicin. This phenomenon might be due to